I saw this post on another forum from Chuck Rogers. When looking at this I'm trying to get my mind around how you could lower the ramp to .400, keep the appropriate angle (31.5) and not decrease the length between the top of the ramp and the barrel ramp. Can someone help me over this mental hurdle?
From Mr. Rogers:
I do not know the source of this picture. I believe it to be fairly
accurate, although I prefer a bit deeper for reliable function with modern
hollowpoint ammo.
Quote:
...I'm trying to get my mind around how you could lower the ramp to .400,
keep the appropriate angle (31.5) and not decrease the length between the top
of the ramp and the barrel ramp. Can someone help me over this mental
hurdle?
All three of those things cannot be done.The only way the 31.5° angle can be maintained while lowering the bottom corner 0.040" (vertically) is to move the ramp forward without changing its angle, by about 0.025" in the "horizontal" direction.
Doing this will also decrease the distance between the top of the frame ramp and the bottom of the barrel ramp by that same amount, or about 0.025".
That drawing is a bit misleading because it does not show the barrel bed. Here's how I prefer to draw it:
PICTURE 404
The dimensions in my drawing are based on the mid-spec values of the Ordnance dimensions, and thus differ from those in the drawing you posted.
Thanks niemi24s. Do you agree with the lower ramp bottom being more conducive for hollow points? If you move the top of the feed ramp forward or closer horizontally to the bottom of the barrel ramp, how would you adjust the distance or 1/32 setback, if you get to close to the barrel ramp? Also if you lesson the distance to the slide stop hole, but maintain the proper barrel ramp distance from the feed ramp top, does that adversely effect anything?
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Do you agree with the lower ramp bottom being more conducive for hollow
points?
No opinion on that as I don't shoot hollow points in a 1911.
Quote:
If you move the top of the feed ramp forward or closer horizontally to the
bottom of the barrel ramp, how would you adjust the distance or 1/32 setback,
if you get to close to the barrel ramp?
Move (cut) the barrel ramp forward to regain the 1/32" if you felt it imperative to do so.
Quote:
Also if you lesson the distance to the slide stop hole, but maintain the
proper barrel ramp distance from the feed ramp top, does that adversely effect
anything?
Moving the barrel ramp forward at its same angle and profile will reduce the amount of support the chamber gives the aft end of the case - which could be a dangerous thing to do depending on the gun's actual headspace.
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Do you agree with the lower ramp bottom being more conducive for hollow
points?
I can't see how that would make a difference unless the bullets are striking below the ramp bottom. How often does that really happen? I usually have a clean spot about halfway up the ramp after a day at the range, so I'm not sure a hollow point is going strike low enough to miss the ramp altogether (although I shoot only FMJ).
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I can't see how that would make a difference unless the bullets are
striking below the ramp bottom.
And I'm not sure that even possible. I just put 2 empty cases in a magazine, inserted the magazine and noticed the scooped-out part in the front of the mag tube was just about even with the ramp's bottom corner.
Seems like the magazine would prevent even a WC from hitting below the ramp.
Maybe moving the ramp forward helps HP's feed better just because the slide & cartridge will have built up a little more speed by the time the bullet hits the ramp? Maybe this extra speed sets the HP back so far its base is into that part of the case that begins to reduce in ID? Maybe this extra resistance to bullet setback helps the HP finally glance up off the ramp into the chamber? Maybe I'm starting to hallucinate?
Would love to understand why Rogers says "I prefer a bit deeper for reliable function with modern hollow point ammo... After final polishing. Now measures .400" deep."
I have a Baer and a Springfield (SF replaced factory parts with quality parts). The depth on the baer is a bout .375 and the SF is about .420 depth. Both eat everything without hiccups.
Original post with pics here, but not a lot of additional info. You can see if you look at marks at the top of the rail the new cut moved the top of the ramp forward.
http://www.thehighroad.org/showthread.php?t=18975
The deep cut on the ramp looks more impressive especially when it is shined up to a mirror polish. Many gunsmiths insist that the mirror polish is absolutely necessary for reliable feeding, and customers generally believe it. As ramp depth is increased the top edge of the ramp moves forward, eventually causing a new set of problems.
I believe you increase the ramp length to accomodate 8 round mags better and some hollow points.
The first "bullet" on the 8 rounder will hit lower than a 7 rounder, as we all know.
And, some HP's are shorter than standard spec ball ammo so they will hit the ramp lower also.
Combine a 8 round mag and some HP's and you might have problems with the standard ramp length.
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I believe you increase the ramp length to accommodate 8 round mags better
and some hollow points.
The first "bullet" on the 8 rounder will hit lower than a 7 rounder, as we all know.
Yes, we do know that, if we are comparing the same exact ammo. However the top round is still constrained by the magazine itself. For purposes of clarification, there is a difference between the ramp length and the ramp depth. The main focus of the original question seems to point to a ramp depth question. The assumption is made that the ramp angle will not be changed from the correct 31.5 degrees.
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Combine a 8 round mag and some HP's and you might have problems with the
standard ramp length.
Agreed. But if I may... "standard ramp depth". This behavior resulted in the never ending list modifications to the original 1911 design that we are all familiar with today. Unfortunately modifying the design to be optimal for wadcutters usually means giving up controlled feeding for "who knows" feeding. Mirror polished feedramps and large relief cuts on the barrel mouth are both examples of ways to increase the likelihood that the wadcutter will eventually find its way into the chamber. Good to weigh what you are giving up as well as what you are getting.
Had previously mentioned I didn't think a bullet could possibly hit below the frame feed ramp because the magazine cutout was "just about even" with it. Guess it's actually a little below it...
...but I still think contact below the ramp is very unlikely.
Which, I suppose, begs the question: could a round nose dive so much in the magazine it could get hung up on the front of the magazine tube?