I recently picked up a used Norinco 1911 with a serial # of 417xxx.
The man I picked it up from said he had put 1000 rounds through it. I did check out the barrel and slide locking lugs for damage before I bought it and it did have some flanging on the lugs(none on the slide though). It isn't hardly noticeable, however, and I have put about 150 rounds through it without a malfunction. I did check the fired brass and it showed no evidence of headspace issues.
After reading some of the posts on this great board I decided to take it to my local gunsmith and ask him if I had anything to worry about. Yes, I was getting paranoid after seeing some of the posts and pics here on this and other forums. My gunsmith grabbed the barrel and slide, took a couple of measurements and said, "don't worry about it, I've seen alot worse on Colts and USGI pistols". He also mentioned that if their is a slightly late linkdown on the barrel, it would only flange a little then stop. My smith also stated "they are very good pistols".
I will post some pics of my barrel as soon as I am able. I was worried about it but I have much respect for this smith and trust his word. I noticed that even the respected Kunhausen(I hope I spelled that correctly) says a little flanging is acceptable. Don't get me wrong, I have seen some real bad Norinco barrels on various forums and I think it is something to check when buying one. I guess my main question would be; does the flanging only go to a certain point on some pistols then stop? This seems to be the case with mine.
One other barrel related possible issue I have with the Norinco is the bore diameter seems to be large. In fact, when doing a "bullet test" with a FMJ 230 grain cartridge, the bullet inserts all the way into the bore to the case rim. Do the Norincos have large bores?(I doubt it's worn out)
At the above mentioned smith's shop he had an Ithaca USGI 1911 and I was surprised how close the Norinco was to this one. It even had the safety click down past the detent when taking it off safe. The "looseness" of the pistols seemed to be the same also.
Does the gun show any loose breech? With the slide closed, can you push the barrel back and forth?
If it does you need to have it corrected or the barrel/slide will continue to beat each other to death.
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Does the gun show any loose breech? With the slide closed, can you push the
barrel back and forth?
You mean end play, correct? Yes, it does have end play but what I understand, most service 1911's do. I haven't measured the endplay, but I know some is allowable.
If what Doug 344474 means by "loose breech" is the fore-aft play of the barrel when locked into the slide & slide off the frame, the average M1911A1 will have 0.0125" of it.
A 1911 with a tightly fitted oversized-hood barrel will have virtually zero play, but I don't think the average Norinco is like that.
The fore and aft play of the barrel in relation to the slide is loose breech.
An acceptable value is 0.001" to 0.002". Much beyond that and the slide/barrel will soon destroy each other.
When the gun is at battery any loose breech (I will use 0.010") will be taken up because the barrel is stopped by the slide stop and the slide is stopped by the barrel. Any gap between the barrel/slide locking lugs will be taken up towards the back of the lugs. When you touch a round off the the slide starts back and the barrel starts forward. If you give the barrel a 0.010" running start before it hits the forward part of the lug recess in the slide it will start pounding out either the slide or the barrel, or both.
If the Norinco has 0.010 of loose breech from the factory, that may be the reason they have a rep for "flanging." Run it like it is if you wish, but soon the locking lugs will go negative and the gun will blow open and jam big time.
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The fore and aft play of the barrel in relation to the slide is loose
breech.
The USGI guns I have looked at in the past always seemed to have quite a bit of fore and aft play in the barrel and I read on one of the posts here that .015 is the limit for G.I. guns. The USGI 1911'S have always seemed to have a good reputation for longevity. I'm a little confused. G.I. 1911's had a reputation for blowing up? I've never heard of a Norinco kaboom either.
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...015 is the limit for g.i. guns.
For a Gov't Model 1911 built to the latest available blueprint data I've got, the amount of play can be anywhere between 0.005 and 0.020 inch (0.0125 +/- 0.0050 0.0075 inch) and still be within dimensional spec.
Furthermore, a mid-spec example of one of these guns rides the link all the way into battery and the barrel hood does not touch the breechface.
It depends on the vertical lug engagement. If there's only about .025 inch of the upper lugs catching the mating slide lugs... the lugs will deform and set back rapidly...which increases the "running start" that douglas alluded to... which accelerates the process. As the lugs deform, headspace increases... which will eventually lead to a ruptured case if you ignore the "Guppy Belly" warnings for very long.
Later production Norincos generally have good vertical engagement of the lugs, and the flanging takes much longer to notice, though it does show up eventually. Unfortunately, most of them also had generous static headspace dimensions, and a lot of endplay... or endshake... which accelerates the process. The headspace in the Norincos was mostly the result of overly deep chambers, which means that it's not in the kaboom direction like the excess that comes from poor lug fit or deformation... which is a good thing.
Flanging from lug deformation is different than flanging that results from barrel linkdown timing issues, and will show a different shape on the front top corner of the lug that appears the same to the untrained eye. The flanging from timing problems is accompanied by a radiused, or rounded lug corner with the flange slightly further back.
With old, unhardened slides and barrels, both barrel and slide lugs were often deformed, but this isn't the case with the Norincos. The barrels are soft... which is partly why they're hard-chromed... but the slides are hard and tough. When yours beats the barrel lugs out of it, the slide will be ready for more... and fitting a new barrel will bring it back up to snuff. The bad news is that... most Norinco slides have a mislocated 2nd lug, making it necessary to remove material from the lug to get it to also bear on the first and strongest lug.
This is an interesting picture showing an x-ray of a 45 as the bullet leaves the barrel. Notice the lug gap?
Egumpher... That gap is normal when the barrel is as far forward as the lugs will allow.
When a barrel with an overlength hood is used... and closely fitted... the lugs are forced into that position when the gun is static/in-battery... before firing. While I like a closely-fitted barrel hood, I don't like to have it fitted with zero clearance between it and the breechface. .003 inch of clearance is of no consequence, either in accuracy... unless you're chasing one-hole groups at 50 yards... or in longevity.
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...most Norinco slides have a mislocated 2nd lug, making it necessary to
remove material from the lug to get it to also bear on the first and strongest
lug.
Is material removed from the #2 lug of the barrel or the slide?
I'm guessing it's the barrel, but if not, how is a slide lug face dressed?
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This is an interesting picture showing an x-ray of a 45 as the bullet
leaves the barrel. Notice the lug gap?
The X-ray shows what a barrel with minimum loose breech would look like. With excess loose breech the gap would be in the other direction.
It is that gap, when to the rear of the locking lugs, that gives the slide the running start I mentioned.
And for the record, I never said the gun would "KABOOM". I wrote that the "gun will blow open and jam big time." There is a big difference.
Does anyone know about the bore diameter "bullet test" that I did?
The bore seems extremely large and just swallows up an FMJ slug.
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Does anyone know about the bore diameter "bullet test" that I did?
Forgot about that part of your post, but don't forget most FMJ bullets' ogives begin reducing the bullet OD at the case mouth. Then too, it might depend on how the muzzle's crowned. FWIW, my "414" NM barrel muzzle comes within about 1/32" of allowing the case mouth of a round of WCC 64 Match ball to touch.
Only way to really tell what the bore or groove diameter is is to slug it.
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Is material removed from the #2 lug of the barrel or the slide?
From the barrel lug.
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The X-ray shows what a barrel with minimum loose breech would look like.
With excess loose breech the gap would be in the other direction.
The photograph is an X-ray of the gun firing, just before bullet exit. The gap couldn't be shown in any direction other than what it is. The barrel is held forward by the bullet's passage, and the slide pushed back by the recoil forces. The gap between lugs is the result of the difference between the thickness of the lugs and their mating recesses.
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And for the record, I never said the gun would "KABOOM".
But if the headspace grows far enough due to lug setback to let the case back up in the chamber and expose the thin section of the case ahead of the web area and blows downward into the magwell... I assure you that it can kaboom, and if the shards and hot gasses cause a sympathetic detonation of any remaining rounds in the magazine... it will be a kaboom that you'll remember for years.
Go ahead and ask me how I know...
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I guess my pistol is normal and I'll shoot it for awhile.
Exactly how much fore-aft play does the barrel have in the slide?
Dan... The amount of fore/aft play found with a slide off test will be more than what is actually present when the gun is static/in battery. The test measures it at the extremes, and when the gun is assembled with the slide held in battery with spring tension...the the slide and barrel aren't at their extremes. So... if, say... the test shows .015 inch of total endshake, when the gun is standing ready, in battery with a chambered round... the operational amount might not be more than .010 inch.
It's like aligning a thrust bearing. The bearing is levered full forward and the crankshaft full rearward. The total amount of gap is .003... but when the crankshaft is spinning, it's pretty much split, with .0015 inch per side.
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The photograph is an X-ray of the gun firing, just before bullet exit. The
gap couldn't be shown in any direction other than what it is. The barrel is
held forward by the bullet's passage, and the slide pushed back by the recoil
forces. The gap between lugs is the result of the difference between the
thickness of the lugs and their mating recesses.
I did not mean to imply that the gap shown was a result of loose breech. As you state, it is the normal clearance between the slide and barrel lugs.
Maybe I was not clear enough. With loose breech of 0.001" to 0.003", the gaps would be as shown, if the gun was firing or not. The lugs would be tight towards the front, as shown in the X-ray.
However, with loose breech of 0.010" (short hood) the barrel lugs would be towards the back or at least the middle of the slide cuts. When the round was touched off, the barrel would move forward while the slide moves back and the lugs would be meeting each other with some force and with time would beat themselves towards a negative engagement. If allowed to go on long enough, the slide could go back and the barrel could go forward, unlocking 180 out of the way it should go. I don't think this would cause a KABOOM moment, but I could be wrong. Either way, I have no wish to find out.
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But if the headspace grows far enough due to lug setback to let the case
back up in the chamber and expose the thin section of the case ahead of the
web area and blows downward into the magwell... I assure you that it can
kaboom, and if the shards and hot gasses cause a sympathetic detonation of any
remaining rounds in the magazine... it will be a kaboom that you'll remember
for years.
Go ahead and ask me how I know...
I have not had that experience myself. Don't really think I want to, so I'll take your word on it. I have no doubt a KABOOM is possible. Unsupported brass ahead of the case head is a no no. And Headspace needs to be considered when making barrel ramp adjustments forward.
Believe me, I read your posts with great interest and attention. I learn something every time I do. Thanks.
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However, with loose breech of 0.010" (short hood) the barrel lugs would be
towards the back or at least the middle of the slide cuts. When the round was
touched off, the barrel would move forward while the slide moves back and the
lugs would be meeting each other with some force and with time would beat
themselves towards a negative engagement. If allowed to go on long enough, the
slide could go back and the barrel could go forward, unlocking 180 out of the
way it should go. I don't think this would cause a KABOOM moment, but I could
be wrong.
I think we're gettin' onto the same page... but there seems to be a little misunderstanding in the works.
With a few thousandths running start, the lugs become deformed faster than with no running start. No argument there... but the "unlocking" that you're describing can't happen on firing. What can happen is that the lug faces become deformed... barrel front face and slide rear face... and allow the slide and barrel to separate on firing... moving further apart, and thus increasing the dynamic headspace. As headspace grows, the case backs further out of the chamber, stopping when it meets the breechface. As the case backs out of the chamber, it gets closer to an unsupported condition. If it gors far enough, it becomes completely unsupported...and the case bursts, blowing out into the unsupported area... the barrel ramp.
On firing, the barrel can't actually move forward any further than the slidestop crosspin will permit. The barrel is held forward, and the slide moves backward... away from the barrel... but the breech doesn't unlock as long as the bullet is present and the system is under pressure. The barrel engages vertically... but it locks horizontally, when the gun fires. Static/in-battery... the gun isn't actually locked. It locks when it fires, and unlocks when the bullet exits and the pressure drops. At that point, the barrel and slide lugs aren't engaged in opposing directions under shearing forces. They're merely meshed, with no pressure on them. You can remove the barrel hood completely... and the gun will still lock when it fires. The hood has nothing to do do with locking. The fit of the hood... the gap between the edge of the hood and the breechface... only determine the position of the lugs in relation to each other before the gun fires. If it's tight... the barrel lugs are placed closer to the slide's than if it's loose. It reduces the distance of the "running start" that they get when the gun fires... but it has nothing to do with locking or unlocking the breech. The function of the hood is to time the barrel vertically into the slide and keep dirt and debris out of the breech area. Nothing more.
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Exactly how much fore-aft play does the barrel have in the slide?
I will measure it(if I can get a feeler gauge in there), based on Tuner's mentioning that the gun has to be assembled. You measure the clearance between the hood and breechface with a round in the chamber(carefully) correct?
Also, can I use a dummy round? I prefer not to load a live round in the chamber in the house.
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From the barrel lug.
The photograph is an X-ray of the gun firing, just before bullet exit. The gap couldn't be shown in any direction other than what it is. The barrel is held forward by the bullet's passage, and the slide pushed back by the recoil forces. The gap between lugs is the result of the difference between the thickness of the lugs and their mating recesses.
But if the headspace grows far enough due to lug setback to let the case back up in the chamber and expose the thin section of the case ahead of the web area and blows downward into the magwell... I assure you that it can kaboom, and if the shards and hot gasses cause a sympathetic detonation of any remaining rounds in the magazine... it will be a kaboom that you'll remember for years.
Go ahead and ask me how I know...
Is it safe to assume a kaboom happened to you? How many rounds went off and were you hurt seriously (hope not).
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Is it safe to assume a kaboom happened to you?
No. With any used pistol that I aquire, I'm adamant over checking it for headspace and head support before I fire it, especially if I see any signs of a "Ramp and Throat Job" or heavy polishing having been done. I normally look for that before I buy, and... based on how things look... I may not buy it at all, unless I figure in the cost of a new barrel with an adjustment on the price.
I have seen it in other owner's guns, and notified them of the condition... with any due warning. A couple chose to ignore my caveats, with predictable results to follow. One of them only had the fired round to burst. The other guy had the worst of it.
The magazine base place was blown off, and the grip panels splintered. The grip frame bulged, but was repairable. Shooting glasses saved his eyes, but his hands didn't fare as well. A surgeon was required to untangle some of the wood splinters from the small bones in his hand and wrist, and he only regained about 90% of the hand's function due to nerve damage.
I've examined a few others that let go, and the common denominator was insufficient head support combined with excessive headspace... without exception... and the headspace issues were accompanied by lug deformation and setback.
Ron... The static endshake test is made with the gun disassembled with the barrel in the slide... pushed into vertical engagement and held fully forward. Measure the distance between the muzzle and the bushing face. Then, push the barrel full rearward, and measure again. The difference is the total amount of endplay.
Tuner, I'm going to measure the end play right now. It's unfortunate that these folks didn't listen to you, I can't imagine losing the use of my hand(s).
Another question, would comparing(measuring) an unfired cartridge case to a fired case(of the same type and brand) properly represent headspace?
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You measure the clearance between the hood and breechface with a round in
the chamber(carefully) correct?
I see no reason to have a round in the chamber for this.
Measuring the fore-aft play of the barrel in the slide can be done by either measuring changes in the hood-to-breech face gap or changes in the chamber face-to-breechface guide block gap. I do it with the slide off the frame. I think the best measurements are taken at the hood area, but this requires narrow (1/4 or 1/8 inch wide) feeler gauges.
Sounds like Tuner does it with the gun fully assembled, so the gap at the hood is the only one that can be measured - unless he does it by measuring changes in the distance between the barrel muzzle and front of the slide.
Ron... Yes. You can measure your static headspace dimension with a fired, resized case and feeler gauges. As with any gauged headspace test, it will only tell you if the headspace is within allowable limits or not. If it's excessive...it won't tell you why. It only alerts you to the fact that something is wrong. Determining exactly what is wrong requires other measurements.
I measured .014 total endshake (.023-.009) with the slide off the frame. I guess it falls within spec for a service 1911.
That's a tad above average for a GI model. What did you get for its headspace?
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That's a tad above average for a GI model. What did you get for its
headspace?
I didn't measure headspace. I did compare a fired case to a unfired case though and it seems like there is no difference in the lengths, based on what I can see(I don't have a caliper). No bulging or backed out primers either.
You'd said your 'smith had taken a couple of measurements on slide & barrel. One of those may have been the headspace. If not, you can do a fair job of measuring it with a set of narrow feeler gauges and an empty case. However, the case must freely fit all the way to the stop shoulder and its length must be known to the nearest 0.001".
Without a caliper (or a micrometer) I'd recommend you either have your 'smith measure the headspace or find the length of a good-fitting case for you to use in measuring it. It (the headspace) should not exceed 0.920".
Ron, you'll have to actually measure it. Straight-walled pistol cases don't stretch with excessive headspace the way rifle cases do.
I don't want to hijack the thread too much but I have a great example using a Metroarms American Classic that I have been working on.
I decided to try to drop in an original Colt Government barrel into my MetroArms as a learning experience so I have the original Metroarms barrel and the Colt to compare.
I measured the barrel foreword/aft play between each barrel and the slide by measuring how far the barrel extended beyond the bushing like this:
I measured:
Metroarms play: .006 inches (after ~ 750 round on the barrel)
Colt Gov Play: .014 inches (after ~ 500 round on the barrel)
The Metoarms has visually less "polishing or peen" than the Colt.
Colt lugs (.014 play @ 500 rounds)
Metroarms (.006 play @ 750 rounds)
Based on this recent inspection I decided to use the MA barrel to avoid undue slide wear.
That's not peening. That's normal, and comes from lug to lug contact under pressure.
When the gun fires... the barrel is under a forward drag from the passage of the bullet.
At the same time, the slide is slammed backward under recoil. The lugs are meshed with the front faces of the barrel lugs in opposing contact with the rear faces of the slide's lugs. The barrel is drawn back with the slide... against the forward drag of the bullet.
That's the breech lock. Barrel and slide locked together by the lugs being pulled apart under a shearing stress. Lock your hands in front of your chest and pull in opposite directions. Like that.
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That's not peening.
I was looking for a better word than peening because this means that metal moved but it didn't
I was impressed by how noticeable the polishing/removal of bluing was between the two barrels.
Can the noticeable difference be due to the extra play (.014 - .006) with the Colt barrel?
OR perhaps the Colt lug is just contacting better?
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Can the noticeable difference be due to the extra play (.014 - .006) with
the Colt barrel?
No.
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OR perhaps the Colt lug is just contacting better?
Yep. More contact area. Given time and use, the contact area will widen as the lugs pressure seat to each other... which means that metal has to be moved... peened if you prefer...but that's a normal condition for the design. When I think of peening, I think of damage.
Years ago, before hardened slides and harder barrels were in use... the normal way to effect equalized lugs was to fit to the first lug, and leave the forward lugs kissing about a thousandth or two of air. Then, the gun was fired with proof-level ammunition to set the first lug back a bit... and to set the slide's lugs forward a bit... to bring the other two into play. Any flanging of the first lug was dressed off, and the pistol reassembled. Once all three lugs are equalized, further setback was minimized, and the gun had the strongest breech lockup that could be achieved with the small radial lugs.
Pressure seating of the lugs can still be done, but the process is different because of the harder steels, and because it's all done with the barrel lugs... one has to be more careful or risk shearing a lug. Seating and equalization will come eventually with use, as long as the non-bearing lug(s) aren't more than a thousandth from touching. It takes a quite a bit of shooting, though. (Hint) The hotter the pistol gets, the faster the lugs deform.
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Yep. More contact area.
Hello and thank you Tuner. You experience is much appreciated and respected.
I am happy to learn the Colt barrel is OK because it doesn't foul as quickly as the Metroarms and shoots great too. (+ it's hotter )
It took awhile, but here's some pics(sorry for the poor quality) of my lugs:
As you can see, the 1st lug(closest to the trigger) seems to have the most flanging. It seems to only run from around 9 o'clock and 11 o'clock though.
Looks like seating from here. I can't see the faces of the lugs. The thing to be watchful for is a stair-stepped shape on the front face, indicating insufficient vertical engagement. Essentially half the lug is bearing the load, which means that setback deformation will come earlier. If you've got full or nearly full vertical engagement, and the lug is just seating... and bringing the other two into play... it won't likely go any further for a good long while.
Meanwhile, dress the flanging with a fine file or a stone and shoot it. Check for further flanging whenever you tear it down for cleaning.
There is the headspace issue to consider, though. Keep an eye on that.
ron burgundy
19th January 2010
Thanks for the quick reply, Tuner. We have a fun show coming up next weekend, I might just try to get a 7991193 barrel over there and try it out in my Norinco (just in case). I'll try to get a pic of the front of the lugs in the meantime. I still haven't checked headspace, maybe I can find a no go gauge the the aforementioned fun show.
I have a mil-spec Norinco (serial 408***) and it was brand new when I obtained it. I have noticed the barrel lugs are getting a pronounced lip after some serious shooting. The barrel is just super soft on my gun... period.
I will say that the basic parts (frame & slide) of the Norco are made very well. I swapped out the stock sear, disconnector and springs for better quality parts, which made a huge improvement in overall feel. I have not altered the stock extractor.
Like my 1927 Colt-Hartford Argentine daily-carry duty-pistol, this gun will shoot any bullet configuration from any feed lip style, including the junk $8.00 Mil-Spec knock-off SARCO magazines, without any FTE/FTF's.
My Dad's Ballester-Molina also functions with any feed lip style or JHP/FMJ/RNL bullet configuration, commercial and handloaded.