1911 9mm Ammo Nose Dive

original: thehighroad.org
Retrieved: November 13, 2011
Last Post: Lanuary 7, 2008

schmeky
January 5, 2008

Having problems with a 1911 I had converted to from .38 Super to 9mm. The top round always "nose dives" and hangs up on the frame ramp. This also happens frequently to the subsequent rounds. I can't get through a full mag without problems.

I am thinking about polishing the frame ramp, just below the barrel ramp, being careful to remove only enough metal to provide a good polished, slick surface.

I have tried 3 different magazines; a new Colt 9mm, a new MetalForm 9mm, and a no-name magazine. All mags display the same feed problem.


1911Tuner
January 5, 2008

Take it over to Wild Bill Caldwell there in Monroe. It's likely somethin' simple. Most feed problems are caused by the magazines.


schmeky
January 5, 2008

Thank you for the reply. Who is Wild Bill Caldwell? I assume he's listed in the phone book? Or has a shop?


JimPGov
January 5, 2008

Common problem. Call EGW. They have a special mag catch which holds up the mag a little higher. It eliminates most of the conversion problems.


1911Tuner
January 6, 2008

schmeky... Bill is a pistolsmith and custom knife maker. Don't know if he's in the book, but you can find him over on Pistolsmith.com forum. You'll have to join, but shoot him a PM and tell him that a pair of ladies named Bobbie Sue and Roxy told ya to look him up.

Your issue is most like magazine related, but in case the ramp needs a little work, Bill will be able to do it without losing the angle and jackin' up the pistol.


schmeky
January 6, 2008

I sent a brand new Rock Island Armory .38 Super frame assembly, new Essex slide, 9mm Match barrel, and all new top shelf parts to someone everyone on this forum probably knows. I wanted the barrel and slide fitted, extractor adjusted, function testing, etc.

When I got the pistol back, it wouldn't even chamber the 1st round, did the nose dive into the frame ramp thing. Would have 2-3 failures to feed with evey mag of factory ball ammo. I was aggravated.

JimPGov,

I'll check into this item this coming week.


1911Tuner
January 6, 2008

Quote:
I wanted the barrel and slide fitted, extractor adjusted, function testing, etc. When I got the pistol back, it wouldn't even chamber the 1st round, did the nose dive into the frame ramp thing. In that case... It sounds like maybe incorrect feed ramp geometry. Can you post a picture?

Just for chuckles... Remove the extractor and see if it'll chamber the top round in the mag.


Old Fuff
January 6, 2008

Are you using 9mm or .38 Super magazines? Also, was the slide intended for 9mm or .38 Super? It sounds like the breechface might be hitting too high on the cartridge head, thus causing the round to nose down.


schmeky
January 6, 2008

No, I have not tried it without the extractor, but I am aware of chambering a round sans extractor for testing. Good suggestion. I have Jerry Knuhansens' (sp) .45 manuals and I use them for reference. I do not delude myself concerning gunsmithing.

I decided to veeerry gently polish the frame ramp with graduated wet/dry paper, 400/1000/2000 then finished polishing with a small crocus wheel in my dremel using a polishing compound. The ramp was very rough before I smoothed it. I then used my lighted magnifying light to examine the barrel ramp. It had fairly pronounced machining marks. I carefully & gently polished it as well. I then loaded the mag to capacity (9 rounds) and closed the slide with the slide stop.

The difference is amazing. It now chambers reliably and sounds completely different. I have chambered about 50 rounds off the top of the mag with no nose diving now. The slide now closes with that "schaaalllcct" sound, with a fluid, smooth feel. I plan to test it this coming weekend.

Old Fluff,

They are 9mm mags.

I'll take a picture an post how the ramp and barrel look after polishing.


Clark
January 6, 2008

I have had cartridges nose dive.

There are a bunch of variables to play with:

How fast is the recoil spring pushing the slide moving forward when it hits the cartridge?

What his the angle of the ramp?

How rough is the ramp?

How far forward is the ramp?

What is the pivot point of the cartridge to nose dive, with the feed lips?

How heavy is the cartridge?

How much force in the magazine spring?

How many cartridges in the magazine that the mag spring must accelerate upward?

What is the bullet shape?

What is the over all length of the cartridge?

Has the cartridge been resized since seating by a Lee Factory crimp die ring?

Are the feed lips bent?

Are the feed lips smooth?

Where does the breech face first strike the cartridge head to push?

Sometimes I load up some dummy rounds and jack round through the action while I watch for what is causing the hang up.


jmorris
January 7, 2008

By far most of the single stack 9mm 1911 feed problems I’ve seen have been the cause of the magazine/s. The most common is a burr on the inside of the magazine (see photo) formed during the stamping process, remove the follower and spring then polish the burr out (a piece of sandpaper around a pencil will work).


schmeky
January 7, 2008

Thank you for your input. I would not have believed the difference a little polishing would have made without experiencing it first hand. This picture didn't turn out very good, but I wanted to show you what I did. I concentrated on just polishing, being careful not to alter any angles and trying to remove as little metal as possible.

PICTURE 404


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