What would cause this..

[Arik]

I picked up a Norinco 1911 yesterday. It is a 1911a1 copy. Took it home, cleaned it (was really dirty inside) and started playing with it to check for function and whatnot. I first noticed that when the slide was back and a loaded mag was inserted the slide wouldnt go forward using the slingshot method. If I hit the slide release it worked fine. After some playing around and about a dozen field strips I realized the problem was that there was an added buffer on the guide rod. Once I took that buffer off I was able to use the slingshot method to release the slide. While doing this I was using live ammo (BLAZER FMJ). I know, they make snap caps for a reason but I found something else that I wouldnt have had I used snap caps. What I found was the rounds that I was cambering were all pushed into the casings. Some more then others and some not at all. Im guessing that those that were really pushed in were chambered more then the others. What would cause this and should I worry?

The ammo was Blazer aluminum casing fmj

[deadin]

What would cause this and should I worry?

Not sure exactly what is causing the problem other than it sounds like something is really out of spec.

Should you worry?? Most definitely!!
If you were to fire one of those rounds with the bullet pushed in, who knows what kind of pressure peak would result.....

[diamonback68]

Check the feed ramp for dirt or burrs.

[29aholic]

With the buffer in place the slide wont come back far enough for the slide release to drop. Chamber needs throated a little to eliminate the bullet push.

[Andy Griffith]

Also, did you take out and rechamber those same rounds many times? If so, that does tend to loosen the bullet from the case mouth, and also the aluminum doesn't tend to keep as firm a grip on the bullet as brass- it's like it is prone to "relaxation" or something. I haven't got a test or anything to prove it, but I've heard that from the few cheap skates that have tried to reload it- maybe it's only prone to that on reloaded ammo...I don't know.

However, feeding the same ammo many times through the action will cause the bullets to back into the case. Be careful as that can cause an overpressure condition.

[Arik]

Originally Posted by Andy Griffith

Also, did you take out and rechamber those same rounds many times? If so, that does tend to loosen the bullet from the case mouth, and also the aluminum doesn't tend to keep as firm a grip on the bullet as brass- it's like it is prone to "relaxation" or something. I haven't got a test or anything to prove it, but I've heard that from the few cheap skates that have tried to reload it- maybe it's only prone to that on reloaded ammo...I don't know.

However, feeding the same ammo many times through the action will cause the bullets to back into the case. Be careful as that can cause an overpressure condition.

Yes. I used the same 7 rounds. After I noticed some were pushed in I loaded one and chambered it. When I took it out it looked fine but a few more re chamberings pushed it in as well.

[Texas Star]

First, try some normal ammo with brass cases, in a quality brand. Not cheap stuff! But don't keep cycling the same ammo through the gun.

That holds for any auto pistol, not just the Norinco and the other Colt copies or the original Colt.

You can also look at the bullets after cycling and see if the chamber is leaving any marks on them, like the chamber may be too short.

Are Norinco barrels interchangeable with US GI barrels? That might be one fix, if you don't have access to a good gunsmith.

My guess is that the aluminum cases and recycling the ammo are causing your problem.

[Arik]

Yes the Norinco is a true copy of Colts 1911a1 and all part are interchangeable.

The only marks I noticed were on the bullets themselves. Some have small indents in them like the bullet hit something (chamber).

Im going to try other ammo and then Im taking it to a Smith to install an ambi safety and I'll have a him look at the chamber. I'll bring those bullets in too for him to look at.


My ultimate goal is to eventually swap all the internals with either Colt or Wilson Combat bullet proof parts. Since the Norincos were made of recycled railroad ties and track steel this should turn into one hell of a bullet proof 1911!

[Rule 303]

As Moon says, get rid of the shock buffers.

Rule 303

[faol]

Yup, the Shok Buffers should go! I have a Norinco 1911 and it's a gorgeous piece! Have a smith do a nice throat and polish job on the chamber/ feedramp. It'll clean those right up! From what you've described, I'd also check the mag springs; just to be safe.

[Arik]

Yea I took that buffer right off! What's the point of those?

[arjay]

The theory is it keeps the slide from battering the frame,but I think if the gun is sprung properly that really shouldn't be a problem. Ymmv

[boatbum101]

Sounds like barrel could be short chambered . Headspace gauge & reamer is the cure .

[310Pilot]

The cause of the rounds having the bullets set back in the cases was repeatedly chambering them. This is typical when chambering the same round repeatedly in any autoloader, but is especially true in a 1911. A lot of forces which effectively push back on the nose of the bullet are encountered every time a round is chambered, starting wit the slide pushing it forward into the feed ramp, after which it is angled up toward the chamber via the ramp. The nose of the bullet then contacts the chamber roof, which forces it to turn into the chamber proper, all the time being forced forward by the slide, with both spring force and the slides momentum acting on it. That is how the gun was designed to operate, completely normal, but it will cause bullet set back, especially when repeatedly chambering the same round repeatedly. That will result in significant increases in pressure, potentially to unsafe levels, which is why that practice is discouraged.