1911 Ramp angles for different calibers

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target221

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Hi all,

I was looking for information on the ramp angle in 1911 pistols for the various calibers. I've got the angle for the .45ACP and I was hoping that someone could fill in the missing info about the ramp angles that work best for the following calibers:

.45ACP ------> 31.5 degrees (measured from the vertical)
.40S&W
10MM
9mm
 
Well I don't know the angle, I do know that my Norinco NP-29 which is a 9mm bottom end does just fine with a .38 Super top-end, a .38 Special Wadcutter top-end and a .45 ACP top-end....It works great with all of them and I never even thought about ramp angle....Go figure.....

The only mod to the frame group, is to thin the right side of the long ejector to work with the .45 slide...same slide-stop (NP-29) for all combos....

Norkenstein_Multical.jpg
 
Rich, Halger's .38 Special runs in a regular .45 slide (yes, with the lugs), and the barrel is a rechambered .38 Super if I remember correctly. This combination runs a specially modified extractor. The trick to making this combo work , is of course, having the proper Colt .38Special magazine, and these are fairly rare.

I really enjoyed building this set-up, and have a few similar toys myself :D

BTW, there's no such thing as any given "proper" ramp angle, even for fully supported 1911 barrels - we all seem to have our favourites. I've seen ones that obviously don't work, of course :) As far as the non-ramped regular set-ups, I've successfully run .45 top ends on 9mm bottoms, vice-versa, 9mm's on Delta Elites, etc. The integral ramp angle I leave as it comes, and it's never been an issue :)

Gunnar
www.armco-guns.com
 
Rich McFarlane said:
By top end, do you mean the colt lugless slide and factory bll. or do you have some other rig?
Click to expand...
The slide is a Norinco .45 ACP slide with the breech-face slightly relieved and a re-shaped and tweaked extractor...
The barrel is a standard 1911 type, match .38 Super re-chambered for .38 Special....it's at the top left of the picture...

The only change to the NP-29 frame is the ejector, which is a long nose type with the right side of the ejector thinned to clear the ejector cut in the .45 ACP slide...works fine and easier to do than milling the slide to widen the ejector cut....All of fitting of parts done by Gunnar of ARMCO...

I took your advice of many months ago and passed on the Jim Clark Magazines...I have 5 Colts and a couple TRIPLE-K's...I tweaked each mag until it would feed un-sized fired cases reliably....it even works with button nose wadcutters although the extra length impairs reliability somewhat, they tend to bind a bit in some of the magazines...
 
7x61 said:
BTW, there's no such thing as any given "proper" ramp angle, even for fully supported 1911 barrels - we all seem to have our favourites. I've seen ones that obviously don't work, of course :)
Click to expand...
Would it be more appropriate if I said "optimal" or "practical" ramp angle? I can see how every gunsmith may develope a different angle based on their own experience, but even so one must start at some angle which is at least thought to be the correct angle (for a given caliber) at least theoretically speaking.

7x61 said:
As far as the non-ramped regular set-ups, I've successfully run .45 top ends on 9mm bottoms, vice-versa, 9mm's on Delta Elites, etc. The integral ramp angle I leave as it comes, and it's never been an issue :)
www.armco-guns.com
Click to expand...
So if one converted a 45ACP with a ramp angle of 31.5deg to a 9mm (by changing the barrel, slide, extractor, magazine) the gun would still feed reliably with 9mm ammo? I am asking because everything I read about this ramp angle indicates that it is important for the feed reliability of the gun, hence it seems to me that a ramp angle used for the 45ACP load could result in problems!

Should one worry more about the depth to which the ramp angle is cut, perhaps even the shape of the cutout?... For all these discussions I am assuming a properly polished feed ramp of course :)
 
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