22TCM 1911 and odd problem...

[mattw]

My daughter and I love shooting this pistol, we just hardly ever do it due to a high percentage of split brass. I am used to the normal 1911 firing sequence, but I think something is going awry with this one. My theory... recoil spring is to light and the gun is unlocking to soon and allowing the shoulder to fireform to far forward and splitting the brass. It splits at the body to shoulder junction. Factory ammo, brand new brass loaded and surviving reloads all do it. BTW, the factory rounds as well as my reloads plunk just fine and line up with the edge of the shroud just as they should. I have numerous 1911's, but this is my only bottle neck one and it is driving me nuts. The other though I have had is to trim one way short and drop it in to see if I am headspacing off of the mouth versus the shoulder.

I have attached photos of a factory loaded round with 2 fired rounds and a reload in new brass with 2 fired rounds. The pressure is not excessive and they are lower velocity than factory rounds.

What do the 1911 gurus think? I am going to test the theory next weekend with the 9mm spring, I am sure it will not eject, but I hope to see properly formed cases.

[Groo]

Groo here
Could be a bad chamber check with the mother ship.
Replace the firing pin block with a flat bottom one.
The hammer controls the lockup much more that the slide spring on a 1911.......
most likely a chamber.

[1Hawkeye]

If the firing pin indent on the primer looks like a tear drop that is a sign of opening too soon and you do need a heavier recoil spring.

[mattw]

The gun has been back to RIA for feeding issues... They polished the chamber... They said the chamber is "in spec" and cannot explain the ugly brass. No teardrop firing pin strike. I am almost to the point of ordering a barrel, I sent brass with it the last time, fired of course.

[Misery-Whip]

Do fired unsized cases plunk? If not its definatly timing. Take a chamber cast see what it says.

[35remington]

The gun absolutely cannot unlock “too soon” presuming the gun is not blowback and has the lugs on top of the barrel, which I think it does.

The recoil spring does not control when the gun unlocks, and the gun can only unlock when the bullet has left the barrel. The gun unlocks after the slide travels rearward and is a function of slide travel rather than spring weight. Here again I am presuming the barrel has the standard lugs on the barrel and is not blowback.

A standard 1911 slide and barrel can be fired with no recoil spring whatsoever and it will not unlock “too soon.”

A tear dropped firing pin indent is more a function of a weak firing pin spring than any unlocking issue being “too soon,”. How locked breech pistols function is frequently misunderstood.

[35remington]

A light recoil spring is needed because the momentum and speed the light 22 bullet gives to the slide is low and the slide would not fully cycle to the rear (if a “45” spring were present) as the spring compresses and reaches its full rated strength. During the brief moment the bullet is in the barrel the preload of any relevant spring is very low and does not influence unlocking.

As mentioned, the gun really is incapable of unlocking “too soon” and this is doubly impossible with such a lightweight bullet of low momentum.

[35remington]

Neck/shoulder splits can also be symptomatic of poorly annealed brass.

Depending upon how the chamber is cut and how you are sizing the cases, as well as trimmed case length, it is possible for the cases to be headspacing on either the case mouth or the case shoulder. Ideally when sizing cases the shoulder is not shoved backward greatly.

Actual headspace is the distance between the headspacing surface (shoulder or case mouth) and the face of the breech when the gun is in battery. When in battery some 1911s have a gap twixt barrel hood and breech, so the “plunk test” is a little misleading if this is the condition that is present. In that instance one would have to determine the relevant condition as it applies to your particular 1911.

[35remington]

I might suggest using a comparator to ensure your sized cases do not have their shoulders shoved back excessively compared to cases that are fired and unsized and have come out of your chamber.

[35remington]

What I think I see in the last picture is a loaded case that has its case shoulder significantly further rearward than a fired case. If “crank er down to touch the shellholder plus a bit” or some other nonmeasuring way of sizing the case is being used, the next step is to see if you can accomplish sizing setting the sized case shoulder only a couple of thou back compared to an unsized case.

Doing it this exactingly does get easier with a comparator. Just an idea to run down that is less of a dead end.

[Earlwb]

I think it is poorly annealed brass or some incorrect brass alloy from Armscor. Us reloaders just live with it. But you can buy the empty cases and anneal them yourself before you load them. That seems to work fairly well. But you may still get some that split the necks anyway. I have some of them split the necks even in the bolt action rifle too.

[onelight]

That is an odd problem , it looks like it would be a good candidate for a chamber cast to see what it actually looks like.

[mattw]

@35remington... The jacketed round is factory loaded and the cast load I loaded. I used factory new brass and always size it to be sure it has a good round mouth and and such. When I size it, I set my size die to stop just ahead of the existing shoulder. The fired rounds are moving the shoulder forward, whether they are factory or reloads in new brass. I can try annealing a few to see if that helps, maybe... maybe not. I just cannot accept a 50% failure rate in factory loaded brass.

[onelight]

It seems to me that if your chamber is cut correctly that there is still to much pressure in the case as it is unlocking.
Is it possible a faster burning powder would help ?

[BK7saum]

How close are the fired cases to plunking back into the chamber? What is the protrusion of the case head beyond the barrel hood? If this was something other than a semi-auto, I'd say that the chamber was cut too deep. When checking the plunk test with fired brass, tap on the case head to make sure the case is fully seated. This will tell us a little more about the problem and rule out the correct or overly long chamber.

As stated by Groo, you can replace the firing pin block with a flat bottomed (not fitted) one and retard or slow the unlocking process.

1: measure how far the fired brass has been stretched or pushed back out past the barrel hood

2: replace the firing pin block before any spring changes

[gkainz]

I recall hearing/reading about Armscor 22 tcm brass having "problems" and the last batch of ammo and brass I purchased, the shop mentioned that this batch was after "they addressed the problems" ... yeah, I know - hearsay and nothing to back it up. Just sharing what I've heard. I've not gotten a chance to shoot mine since my last ammo purchase, so I can't verify anything right now.

[roysha]

I am going from what appears to me in your photo. The shoulders on the cases on each side of the factory round, definitely appear sharper and further forward than the factory round.

The photo below shows a factory round with a resized case on the left and a fired but unsized case on the right. Note the shoulders are all in the same place and same angle. My very inexpert opinion is that you have a faulty chamber. I have shot nearly 1000 rounds through my TCM and other then some pretty crappy groups, (patterns) with some of the cast bullet loads, not one problem. I will say one thing however, shooting a TCM in the 9mm barrel just doesn't work very well. Really hard on brass.

[1006]

The brass photos certainly paint a picture of the chamber being too long. Maybe the factory reamed the chamber when you sent it back.

[Virginia John]

I shoot and reload the 22TCM and in the beginning I remember having my fair share of trouble with the sizing and crimping. I am not saying that you do but you may want to look over your protocol and make some scrupulous measurements. You may find it is not the weapon at all.

[mattw]

Currently, I am splitting between 40 and 50 % of the brass, does not matter if they are reloads or factory new.