Any experiences or thoughts on keeping the narrow spring guide that uses the 7lb inner spring with standard 16lb 1911 over it, vs. switching to a standard GI short guide & Wolff 23lb single spring?
Better off fitting an EGW square bottom firing pin stop and running a 20# spring. Might even be able to drop it to an 18 or 19#. Don't do that without the new stop though. You will also need to keep a full power mainspring (23#) to do this.
If memory serves me... Ned Christiansen settled on a nearly square bottom on the stop... a 25-pound mainspring... and 18 for the recoil spring in his 10mm builds.
Certainly help to avoid pounding the slide stop pin, bottom lugs of the barrel, and the risk of egging out the slide stop pin hole in the frame. I've seen it and it ain't pretty...
If I could only convince the "More spring to stop the frame destruction" crowd of that little fact, Bill.
The "recoil" spring's primary function is returning the slide. Whatever else it does is incidental.
You are right on the mark there. I have gotten some funny reactions when I tell people that Glock uses the same spring rate recoil spring along the lines of frame sizes. For example the Glock 17, 22, 34, 35 all use the same recoil spring. They look at me and argue.... THAT CAN'T BE... the 40 MUST have a stronger spring. NO... the spring is there to move the slide forward and load the next round.
Glock controls recoil with slide WEIGHT. If you look inside various models they are cut differently to remove mass for the light calibers. The 10mm Glock 20 has THICK slide walls to retain weight. The model 34 has a BIG window cut in the slide and metal machined out along the inner areas where the barrel sits. The slide is longer than the 17... uses the same spring... and so the slide must be lightened to equal the weight of the 17 slide.
When I convert a Delta to a single recoil spring I run a 19 or 20 pound and use a flat bottom FP stop and a 20 pound main when using 10mm loads that replicate hot 40. For full house ammo the main goes to 23 or 25 depending on load.
A person has to fool the gun into thinking the slide is very heavy. That is better done with the main spring. Running super heavy recoil springs opens a whole new can of worms.
Mac & Tuner, while I have both of you here, I'm gonna ask another odd question in regards to this Delta. I had the FP block break in a Colt XSE a few years back (internal metal looked porous, maybe was a MIM part), and that lead to my distrust of FP blocks in 1911s. I made an exception buying this Delta, since all Delta Elites are Series 80. So here are the questions:
Does anyone make a machined from heavy duty rod stock Colt S80 FP block?
Or, if I ditch the S80 parts, is there a preferred alternative to welding to fill the FP actuator cutouts?
Which part broke? There are four, if you count the spring?
None of them are MIM.
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...I had the FP block break in a Colt XSE a few years back
Did it show evidence of improper timing? Was the hammer dropping before the firing pin plunger had cleared the firing pin? That would show up as peening on the body of the plunger and the shoulder of the firing pin.
I've never seen one break that was not due to improper timing.
Very few folks weld the hole in the slide. Messing up the heat treat is a concern. They just leave them open.
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Or, if I ditch the S80 parts, is there a preferred alternative to welding
to fill the FP actuator cutouts?
The holes won't cause any problems. I have a Delta that I pulled the Series 80 parts out of the day I bought it. It's had over 10,000 rounds through since. It was my IPSC gun for over 10 years. All I did was round off the little actuator doohickey (I have no idea what it's called) so that it would act as a spacer for the pin. I know they now sell parts designed to do that. Never had any problems.
Got to be a timing problem. A correctly timed Series 80 system is reliable and trouble free.
In the early days, I rarely saw a timing issue with them. Nowadays, it seems like it's cropping up a lot more often.
You don't need to weld up the frame. Order a TJ's frame blank from Brownells. It fills the space left by both frame levers. Be sure to remove it and inspect it every couple thousand rounds and dress the flanging around the holes. Replace it when it needs to fourth dressing. They're only about 5 bucks, so it's probably a good idea to order 2 or 3.
The Delta has been updated a bit. I have wide and really short fingers, which is why I made some of these changes.
First, I took the wraparound grips off, and put a set of standard checkered rubber grips on it, until I decide which nicer grips to install. I just can't bring myself to cut the front strap out of the pistol's original Delta medallion grips. Midway was out of the smooth, polished blue, Ed Brown flat MSH. As a temporary solution I ordered the $8 Colt grooved Delrin plastic flat MSH, which is just the flat version of the factory MSH anyway. Those changes took care of the grip length.
I shoot with a high thumbs grip too, so a beavertail grip safety was a must. The Wilson semi drop-in fitted surprisingly well, and will let me put off frame tang cutting & refinishing for a bit.
Per y'all's advice I ordered a 25lb mainspring, and put that in the flat MSH. I recycled the other small parts out of the arched MSH. I also ordered the EGW Series 80 oversize flat bottom FP stop. I've done a much better job fitting small parts in the past. I'll admit that my fitting of the new FP stop wasn't pretty, but it is functional. I ordered a Wolff 18.5lb recoil spring, and a Wolff 20lb recoil spring. I already had a standard GI short recoil spring guide. I went ahead and put the an extra power firing pin spring (Wolff is including these with their recoil springs now) in while I had the slide apart. When / If I pull the S80 parts the spring is ready for a Ti firing pin.
So, everything fitted, I took it to the range tonight with the 20lb recoil spring in it (I'll run the 18.5lb soon). Ammo was 50 rounds of Atlanta Arms & Ammo reman' 180gr JFP. The felt recoil difference & improved shooting comfort were amazing. No doubt the heavier mainspring and square bottom FP stop were the main factors. I'm sure the improved grip configuration didn't hurt either.
In short, thank you Mac & Tuner for the great guidance on 10mm 1911 setup.
Delaying the slide a tick longer makes quite a bit of difference in how fast it compresses the spring and in how hard it hits the impact abutment... which is where most of the felt recoil comes from.
The explanation is fairly simple.
Delaying the slide at the outset of the action/reaction robs it of momentum before it gets a full head of steam. Harder to slow it down after it's moving at full speed than it is before.
It also places the bullet farther along in the barrel relative to the slide's position... which means that the bullet clears the muzzle earlier in the system's movement... which removes the accelerating force sooner... which means that the slide starts to decelerate sooner.
Little things mean a lot sometimes.
The recoil system creates an action/reaction event separate and apart from the ballistic event. The spring is the force vector. The stronger the spring, the harder it pushes forward on the slide and rearward on the frame as it compresses. The slower the spring compresses, the more time it takes for the slide to hit the abutment... and spreads the reaction out over a longer period of time.
You've just discovered a little-known part of John Browning's genius.
I use a 24 pound recoil spring in my CDE.
The return of the slide is slowed down somewhat by the picking up of the next round.
There is nothing to slow down the slide going backwards except the recoil spring.
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There is nothing to slow down the slide going backwards except the recoil
spring.
Well... no... but the "recoil" spring's primary function is returning the slide to battery... not decelerating it. That's why it's there. That it does decelerate the slide is incidental, and the result of being compressed so that it can perform its primary function... returning the slide.
Look closely at all the things that work to fight the slide's acceleration and momentum the instant that it starts moving... is what.
One is hidden, and sometimes not readily understood.
I have a Delta that I've had no real problems with but it always seemed to be "not quite right". I always took the recommendation to run these heavy recoil springs and just live with it.
I have a squared off FP stop and heavier mainspring on the way from Midway, should be here tomorrow. Your explanation makes perfect sense, wish I'd known of this years ago.
I said there's nothing to slow down the slide's rearward movement except the recoil spring. Is this wrong?
I also said that the slide picking up a round as it comes forward slows down the slide a little. Is this wrong?
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I said there's nothing to slow down the slides rearward movement except the
recoil spring. Is this wrong?
Everything that has the opportunity to delay or decelerate the slide will do just that. Known as "Outside Forces" as per Newton 1B. To wit: An object in motion will remain in motion unless and until it encounters an outside force. Nothing is everything, but everything is something.
The mainspring is part of it. The slide cocks the hammer, and the mainspring powers the hammer... so the mainspring and the hammer's inertial mass fight the slide's acceleration.
The recoil/action spring is a part of it, of course... but that's not why it's there. The gun can be fired without a recoil spring, and about all that will change is that the shooter will have to manually push the slide back to battery. If you want to test this, I suggest using a full-length guide rod. A standard "stub" guide rod will get cattywampus and crash the gun.
The main delaying force acting against the slide is the passage of the bullet through the barrel... pulling forward on the barrel via friction while the slide drags it backward. This robs the slide of more speed and momentum than all other outside forces combined.
The barrel's inertial mass is fairly significant. The slide carries the barrel with it for a short distance... so that has to be factored in as well.
Rail friction also works to decelerate the slide, even though its influence is miniscule. Gravity is another outside force, small though it may be. Even a gnat that flies into the path of the moving slide represents an outside force. Everything is something.
I picked up a Delta the first year they came out--using factory loads it did not take long to break the slide stop--I took it back to the gun shop & traded for a 45 & never looked back.
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I said theres nothing to slow down the slides rearward movement except the
recoil spring. Is this wrong?
What I am getting from this, and the reason the light bulb came on for me, is that there ARE things that work against the slide to delay it a bit and weaken it's rearward movement besides the recoil spring and it just never occurred to me until these guys brought it up.
The squared off firing pin stop makes the initial movement to the rear a little harder to get started, as does the heavier mainspring by making the hammer harder to re-cock. After this initial hard start there is less energy left in the movement of the slide so you can get away with a lighter recoil spring.
That's what I'm getting from the smart guys conversation anyway. It makes complete sense now that I've seen them explain it and I hope it makes my Delta better behaved and more manageable.
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I hope it makes my Delta better behaved and more manageable.
I think you'll be pleased. Be sure and let us know.
I've been using the small radius on the firing pin stop since way back before EGW started offering the ones with the square bottoms. When the small supply of originals dried up at the gun shows, I made my own.
Just for the record... again... I used them as SOP for reliability tweaks... never for recoil reduction. That they did have an effect on the way the guns behaved in recoil was a bonus, but it was never the intent.
Now on to JERRY's point of the feeding round slowing the slide as it returns to battery... yes. That's absolutely correct. It does.
But...
It's still a standard 1911 frame and it still has a standard slidestop crosspin and it still has standard lower lug feet on the barrel. Using a 24- pound action/recoil spring still represents a 50% increase in impact momentum over the 16-pound spring... and going by the original specs... even a 16 pounds is overspringing the slide a bit.
The slide's forward momentum is essentially brought to a sudden stop by the lower lug feet hitting the slidestop pin... which in turn impacts its mounting holes in the frame. Those lower lug feet are pretty small, and the frame walls that the pin passes through are fairly thin. The lug feet can be pounded and deformed and the holes elongated earlier under 50% more more impact than they were designed to handle in the long term. It's also possible for a vertical crack to form adjacent to the bottom of the holes. I've seen it a few times in LW Commanders with as few as 5,000 rounds down the pipe from shooters using 20 pound springs in the mistaken belief that they're "saving" the frame.
The impact abutment was designed to take the impact. The lower lug feet and the slidestop holes, not so much.
Using overly strong action/recoil springs doesn't keep the gun from breaking. It only changes the place that it breaks. There just ain't any such thing as a free lunch.
TR, come back when you get everything installed, and let us know you like the new setup. I think you'll be impressed.
Tuner, you think a square bottom stop, stock mainspring, and dropping to 14lb recoil spring would increase life on a SA full size lightweight in .45 ACP?
Don't know about increasing the life of the gun to any appreciable degree. The frame isn't the concern anyway. It's the slide that takes the real pounding and the spring has no bearing on that. The slide and barrel assembly is the gun. The frame is essentially no more than the gun mount and the housing for the controls.
There are reports of 1911s enduring tens of thousands of rounds, and wearing out multiple barrels. If the frames were all that fragile, they wouldn't do that with any reasonable spring rate. Far too much is made of "Frame Pounding" and I suspect that it was started by the people who are in the business to sell springs and shock buffers. You know... First convince the buyer that he "needs" it, and then sell it to him.
Back in the day when the 1911 was first adopted up to the mid 1940s, when GI contracts ended forever... the US Army ordered several slides and barrels... along with literally dozens of various other small parts... for each pistol delivered. Neither the slides nor the frames were heat-treated and hardened. Yet, the frames remained in service through multiple slide and barrel replacements... all the way up to the point that they were so badly worn out that you could almost field-strip one by shaking it vigorously.
I've rebuilt a number of these rattletrap frames, and after a little rail peening to reduce the vertical play, they all work fine. Oh, they're often cracked at the front of the rails, but that's really neither here nor there. Nature of the beast with sharp corners and thin cross-sections... and the cracks are self-limiting.
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I made an exception buying this Delta, since all Delta Elites are Series
80.
Huh! That's the first time I've heard that. My stainless Colt, Delta Elite is a Series 70 model, Ser. # DS010XX. I pre-ordered it before they were ever released for sale.
You might want to look a little closer. The Delta Elite came along in 1987... four years after the introduction of the Series 80s. Unless you special-ordered it from the custom shop... and by that point, Colt didn't likely have any pre-80 slides and frames left... it's probably a Series 80.
I stand corrected. I just went out and re-examined it and it is a series 80. I've got so many 1911 models that I get them confused I guess.
Good thing is it's a 5 minute job to turn them all back into Series 70 That's the first thing I do when I get a Series 80... take all that plunger out and grind the little thing-a-ma-jig down round so it's just a spacer. Not on a carry gun of course.
Got my squared off FP stop from Midway today, and a new heavy mainspring, can't wait to try this out.
Tuner (and others) I have another question though. My Delta has been using a full length guide rod since the day I got it. I threw the Colt short plug and double spring in the trash literally the first day I had the gun.
While I had it all apart I figured I'd go back the original way so I ordered a standard 1911 guide rod and plug. When I put it back together it was very difficult to push the plug in far enough to turn the bushing. Is it possible that this plug is too long and needs a little hit with the Dremel? And, if it's too long what am I going to beat up shooting it like this? I got it in far enough for the bushing to turn but I wonder if I'm impeding the slide going all the way back somehow?
Does my question even make sense?
Hmm. Never ran into a plug too long. Too large in diameter or swelled/deformed maybe.
Run it in and out of the bare slide without the spring and see. Look for scraped areas on the finish for a clue as to what you've got.
About this squared off EGW series 80 firing pin stop, I'm looking at Midways web site but I don't see a EGW, squared, series 80, 10mm firing pin stop much less a stainless one listed. They have (out of stock) EGW stops for 9mm and 38 Super series 80, 1911's and series 70 .45 ACP only, listed.
The firing pin stop in my stainless Delta Elite is rounded on the bottom where it contacts the hammer as the slide comes back to cock it.
It would seem that a stiffer mainspring might be more productive but a squared FP stop would seem to cause more wear on the FPS and the hammer as would the added main spring pressure on the guide rails.
I'll re-read this whole thread untill I feel I understand what everyone is getting at but at this point I'm just confused.
My Delta Elite is stock except for an adjustable (stop) trigger and a beaver tail grip safty and I've never noticed any problems with it. I do recall seeing some light peening on the firing pin block when I last detail striped it.
Bar-Sto fitted a new barrel to it and it shoots extreamly tight 1" groups exactly to point of aim at 25 yards.
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About this squared off EGW series 80 firing pin stop, I'm looking at
Midways web site but I don't see a EGW, squared, series 80, 10mm firing pin
stop much less a stainless one listed.
Well I may have ordered the wrong thing, this being new to me. I got Wilson "Square Bottom". I don't know if that's the same as the EGW or not. Hope I didn't get the wrong part.
Quote:
Hmm. Never ran into a plug too long. Too large in diameter or
swelled/deformed maybe.
OK that's odd. Maybe it's not too long, it just feels that way. It's not going in far enough to lock in place with the bushing very easily, so something is hitting something, have to play with it and figure out what I've done.
The Series 80 EGW .38 Super FPS is correct for the Delta Elite. The Wilson is not a true squared bottom like the EGW.
The square bottom firing pin stop does work as per Tuner's advice. As a matter of fact it worked so well in my Colt LWT GM that I found a warranty issue with my gun. The pistol worked just fine with the factory FPS (or so I thought). When I installed the EGW FPS the slide jammed open in a full recoil position. Why you ask! Colt did not bevel the inside rearward edge of the slide recoil spring tunnel and the recoil spring was getting squeezed in between the slide and RS guide. Tuner put his finger on this problem too.
Colt did bevel the slide, but not as much as I'm used to seeing. The pistol seems to be working fine now with the EGW firing pin stop re-installed. I didn't tell Colt that a modification showed a discrepency in their product.
After reading and posting in several threads I sold all of my other recoil springs on e-Bay and will now only use the correct ones.
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It would seem that a stiffer mainspring might be more productive but a
squared FP stop would seem to cause more wear on the FPS and the hammer as
would the added main spring pressure on the guide rails.
Most people don't leave the corner dead square, but cut a light radius or a bevel. I use a 1/16th radius... but some do leave it square. I've had the firing pin stops in my two main beaters for something over 375,000 rounds about evenly split... with the OEM hammers. Never a problem.
The mainspring doesn't have any effect on the frame rails, and using a 25- pound spring is only 2 pounds above standard, so not much chance of damaging anything. The gun just isn't that fragile.
OK, I have re-read this entire thread now and if I have it right?
For the average shooter using hot factory loads, he would do well to replace the stock Colt firing pin stop with an Evolution Gun Works, EGW, Oversized Series 80 - 9mm/38 Super firing pin stop which does not come in stainless steel but it is hardened to Rockwell 48 Rc scale steel and must be fitted to the slide and very slightly radiused and polished on the edge that contacts the hammer.
Next, remove and replace the dual recoil spring pack with a single 15 lb. recoil spring and a standard G.I. spring guide and no buffer pad.
Then replace the hammer mainspring with a 25 lb. spring.
Then go to the range and try it out.
Have I got it right or not?
One last question, how would you measure the spring pressure(s) to be sure they are correct? It would seem that you would squeeze the spring down to it's mounted length on a scale and see how much pressure in lbs. is exerted on the scale, much like you would on a automotive valve spring tester I would think.
If you intend to shoot full house 10mm, you might want to go with an 18 pound recoil spring as per Ned Christiansen's research.
Reading through all this wisdom - one question remains:
What do I do if my Colt Delta Elite works just fine the way it is?
It has a single recoil spring, some short stubby plastic (did Colt really make those?) recoil spring guide, so some previous owner must have already modified it from original.
Works great and I am looking for reliablity before anything else. Now you guys have me worried about 80 series parts, some different firing pin stop I don't even understand and timing issues...
The only thing I don't like is some kind of sticky feeling when pulling the slide back against the stop, which (I think) is because of the 'plastic' spring guide as compared to the solid metal clunk of a PT1911 with a full length (metal) spring guide.
If this is in fact the reason, I could see me changing this part to a metal version.
To make things even more confusing, here is a quote from the Wolff website:
"With the exception of recoil and magazine springs, all other springs offered by W.C. Wolff Company for use in 1911 and Commander series pistols (Hammer Springs, Magazine Catch Springs, Sear Spring, Plunger Tube Spring, Firing Pin Springs, Firing Pin Safety Springs) are the same for the Delta Elite 10mm pistol".
I would think the folks at Wolff know a thing or two about springs, so what is up with the 'main spring' being the same to all other 1911s?
Quote:
I would think the folks at Wolff know a thing or two about springs, so what
is up with the 'main spring' being the same to all other 1911s?
The mainspring is also referred to as the hammer spring by some.
Quote:
It has a single recoil spring, some short stubby plastic (did Colt really
make those?)
The original GI 1911s used a short metal recoil spring guide. The Colt original part on the Delta Elite was plastic, but was a smaller diameter to fit the inner spring of the dual recoil spring.
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Now you guys have me worried about 80 series parts
Listen to Tuner. Ignore my comments about the S80 parts - I'm weird about them. The timing is also related to the Series 80 parts. I basically understand it, but not well enough to explain it like Tuner can.
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some different firing pin stop I don't even understand
The firing pin stop is the little plate on the back of the slide which holds the firing pin into the slide. If you look at the bottom of the FP stop it's radiused. The EGW oversize stop is left squared off on the bottom so that the end user can select however much (or little) radius to put on it.
The small radius on the firing pin stop adds a little delay to the slide. Not much, but when things are moving fast, a little change can have a large effect. It does this by lowering the stop's contact point with the hammer, reducing mechanical advantage in accelerating the hammer. The resistance... the outside force... comes from the mainspring's load and the hammer's inertial mass. Those things must be overcome, and there's only so much driving force and momentum available. The more of it that's expended in overcoming the hammer's movement... the less there is left to keep the slide moving.
By delaying the slide that extra bit, it puts the bullet farther along in the barrel relative to the slide's position, and the bullet escapes earlier... relative to the slide's position...which removes the accelerating forces from the slide earlier. Think of it like a drag race driver stabbing the brake just as he launches the car. Once that momentum is lost, it can't be regained... so the slide is moving slower as it compresses the spring... and slower when it hits the impact abutment. Lower velocity means lower momentum... and impact momentum is what flips the muzzle.
Much is made of the short variants requiring heavy springs in order to keep the slide from hitting the frame "too hard"... but that comes from a basic misunderstanding of the physics involved and of the mechanics of the gun itself. Mostly, it's a misunderstanding of the spring's true function. The spring is there to return the slide... not to decelerate it. That it does do that is incidental.
It's moving faster because of its lower mass... but with the recoil spring removed from both pistols...the 5-inch and the 3-inch... it will hit no harder. It can't. Momentums are equal in both directions. It can't have more momentum than the bullet, even though it's moving faster than the more massive slide... and momentum is what whacks the frame and causes it to move.
In reality, the short, low mass slide probably doesn't hit the frame as hard, all else assumed to be equal. The shorter barrel causes a velocity loss, and because momentums are equal and momentum is a function of Mass X Velocity... the short slide has less momentum than the 5-inch gun.
And to expound further... With equal springs...equal outside force... the short slide will still hit with less impact momentum.
The lower the mass, the faster it decelerates when it encounters a given outside force. More... the higher the velocity of a given mass... the harder a given outside force fights it, and the faster the moving mass is decelerated faster.
Timing:
There will be no timing issues. Springs don't affect timing. Timing is mechanically fixed and the timed function will occur at the appointed place, regardless of how fast or slow the machine runs. Springs affect time, which is a function of speed and distance.
Thanks for the explanation - there sure is a lot of physics going on in an 'dumb old fortyfive'.
So I guess I need a larger diameter, metal guide rod to replace the original plastic Colt one because the previous owner did switch to a single spring?
What is a good source for this part? We'll see if that gets rid of the sticky feeling.
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What is a good source for this part?
http://www.midwayusa.com/Product/287...overnment-blue
Well I managed to sneak out a couple of hours this morning and shoot a little, including 75 or so rounds through this Delta. I was shooting some old Georgia Arms reman stuff I had, so it's not Norma 10mm hot, but a bit more than IPSC major so a good middle of the road load I think.
Seemed to work pretty good. I really like having a lighter recoil spring, makes manipulation a lot better. Functioned 100% and didn't throw the brass a mile away so I guess it's OK? Not sure what to check to see if I'm hurting anything though.
When I got home I took the gun apart to clean it and it went back together without the problems I had before so that recoil spring plug must simply have been tight and needed some breaking in. Dunno. Could barely get it in over the weekend and today I could do it without a bushing wrench so that's good.
I guess I'm good to go, just wonder if there's something I should look for to make sure I'm not beating the gun to death.
Has anyone experianced a shift in the impact point after changing the firing pin retainer and springs? Just curious.
A shift in which impact point? Slide to frame impact point is fixed. It can't shift. Hammer to firing pin stop contact point is lowered, which reduces the mechanical advantage... which makes it harder for the slide to cock the hammer... which absorbs some of the slide's speed and momentum.
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A shift in which impact point? Slide to frame impact point is fixed. It
can't shift.
OK, assuming the bullet is in the barrel for the same length of time, which it is, is the barrel unlocking at a slightly different time in the recoil cycle, there by effecting the impact point of the bullet on the target? Or has the bullet already left the barrel when it starts to unlock?
If we are slowing down the slide, even by a miniscule amount by changing the FPS (firing pin stop) does it effect the impact point on the target?
What have others experianced after they have made the recommended modifications on a Colt, Delta Elite hand gun.
Quote:
Or has the bullet already left the barrel when it starts to unlock?
I think so but it's just a guess. I just did this overhaul on my Delta and it shoots the same anyway. Only have 100 rounds or so through it since then, but I didn't see any difference at all in the way it shoots, just easier to manipulate with the lighter recoil spring.
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OK, assuming the bullet is in the barrel for the same length of time, which
it is, is the barrel unlocking at a slightly different time in the recoil
cycle...
The barrel can't unlock at a different time. You've got time confused with timing. They're not the same thing. Timing is mechanically fixed. Time is a function of speed and distance.
The barrel reaches the start of linkdown at nominally 1/10th inch of rearward travel, regardless of where the bullet is and regardless of how fast the system is moving. The only thing that changes is the bullet's location relative to the slide's... and that's straight line. So, there will be no change in point of impact from that function. There may be a change because of the slight difference in the recoil dynamics, but it'll be very slight.
Autopistols aren't subject to the same impact shift under recoil as revolvers are because the actual recoil from the ballstic event isn't solidly connected to the frame. With the auto, the "gun" is the slide and barrel. The frame is essentially just a gun mount and a housing for the controls. The only connection between the gun and mount is through springs. What you recognize as felt recoil... muzzle flip... mostly comes from the slide impacting the frame, and by the time that happens... a 230-grain bullet at 830 fps is about 20 yards downrange.
(Quote)
The barrel can't unlock at a different time. You've got time confused with
timing. They're not the same thing. Timing is mechanically fixed.
No! No! that's not what I'm saying, I know the mechanical timing is the same.
I'm talking about the barrel? slide lifting up during the recoil moment as, before or after the bullet exits the barrel.
Is the bullet in the same place down or out of the barrel when the barrel unlocks from the slide.
I guess the only way to know is after I change mine and see what happens. It is accurate enough to tell if it was changed.
The EGW, FPS should be here today and the springs, tomorrow.
I should have the FPS fitted by then.
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Is the bullet in the same place down or out of the barrel when the barrel
unlocks from the slide.
By the time the barrel links down, the bullet is long gone.
OK, the new EGW, oversized 9mm/38 Super/40 cal. FPS came in the mail today. I got it carefully fitted and reblued. Installed a standard G.I. recoil spring guide and temporarily used a G.I. .45 recoil spring untill the new springs from Wolff come.
The slide of course is much easier to pull back but it is noticeably harder to start it coming back which is what were after in the first place. I'm anxious to try it out.
One thing I'm still not clear on is whether the use of a recoil buffer pad is needed or not or does it even matter?
Again... Other than for a few rounds to test it... if you're using full- house 10mm ammo, I'd stick with Ned's recipe. I learned a long time ago to listen to the man with experience, and I don't have a lot with the 10.
No shock buffer With Ned's set-up is necessary unless it just makes you feel better. Might not be a bad idea if the GI spring is true USGI spec... which is about 14 pounds.
He didn't write an article. He told me about it when we were discussing the firing pin stop radius.
Springs came today and I've got them installed now. It really makes it a lot stiffer to get the slide moving. I tried it without the recoil spring installed and it took 17 lbs. of effort to get the slide to start moving back. I made the mistake of not measuring it before I changed the firing pin stop and springs but I'm not in the mood of changing it back just to find out, sorry, maybe sometime when I get bored and want something to do.
The new 18-1/2 lb. recoil spring really adds a lot of effort to racking the slide back, but there again I forgot to measure it with the stock Colt springs.
Oh! BTW, It went from a 4 lb. trigger pull to a 5 lb. pull with the heavier hammer spring.
Now to get time to go try it out.
Hm. The stock Colt recoil spring is listed at 22 pounds. An 18.5 variable rate spring should make it easier with the hammer cocked.
The added effort to get the slide moving is caused by the combination of the heavier mainspring and the small radius on the firing pin stop. Once the hammer moves as far as the half-cocked position... true half-cock position... its influence ends, except from a little friction.
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Hm. The stock Colt recoil spring is listed at 22 pounds. An 18.5 variable
rate spring should make it easier with the hammer cocked.
I didn't buy a variable rate spring, just a standard rate 18-1/2 lb. Delta Elite spring, part# 42118 From Wolff Springs. They state that the factory Colt Delta Elite spring is rated at 23 lbs.
I tried it with the hammer cocked and it required 14 lbs. effort to get the slide moving.
With the hammer down it required 28 lbs. effort.
Maybe I should check it with the original dual recoil spring set and see what effort it takes with and without the hammer cocked.
OK, curiousity got the best of me.
With the stock Delta Elite dual recoil spring and the hammer cocked, it takes 9 lbs. effort to get the slide moving.
With the hammer down it took 25 lbs. to get the slide moving. This was with the 25 lb. hammer spring because I didn't want to go to the trouble to swap it out again.
Yep. Been tryin' to tell the folks that the mainspring's got more influence on the slide's acceleration than the recoil spring while the bang event is goin' on.
Just got the Wolff 10mm spring, listed at 23 lbs and man, is it stiff.
My hands/fingers slipped off the slide several times trying to rack the slide.
Should I keep it locked open for a while? Will that wear the pressure down more so then shooting it?
Also got the Ed Brown full metal, short spring guide and it fits perfectly with the correct diameter.
Have not had time to shoot it yet. Will report.
And yes the plastic soft feeling is gone, metal to metal against the stop.
By the way the Wolff recoil spring is shipped with a free firing pin spring. Don't know why they do that - should I drop that one in also?
Do they even wear out much?
Also got a Wilson Combat 9 round mag. Looks wide at the top but fits o.k. Need to shoot it.
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Just got the Wolff 10mm spring, listed at 23 lbs and man, is it stiff.
Is that the 23 lb. recoil spring? I'll bet it is stiff, I got the recommended 18-1/2 spring for hot loads and it is stiff enough at that. I also used the 25 lb. hammer spring.
Yes, swap the firing pin spring when you swap the recoil spring. They don't wear out as quickly but they perform an important safety function (without Series 80) so you don't want to get to the point where it's worn out.
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Should I keep it locked open for a while? Will that wear the pressure down
more so then shooting it?
Better to get the 18-19# recoil spring, 25# mainspring, and square bottom firing pin stop to set it up properly.
OK! I got to shoot my Delta today, not under the conditions that I would prefer, but! I did get to shoot it.
I wanted to check accuracy but couldn't and I wanted to see how the ejected brass behaved but didn't.
The gun behaved quit nicely. I wish that I could get slow motion video of it in action but I cannot. The fired brass looked very good as well as the primers.
I fired both my hottest ammo (135gn Nosler JHP @ 1412 FPS with 13.8 of AA7) and my lighter load of 175gn cast lead @ 1340 FPS. Anything less and I would just use my .45's.
I'm happy but I still want to shoot it under my ideal conditions later though.