Is my chamber to large on my 1911?


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yzguy
May 27, 2003, 02:06 AM
I have been having problems with extraction from my 1927 (more info on the pistol here (http://www.1bad69.com/gallery/?path=/gallery/GunStuff/1911/)).

I did not have a problem shooting Winchester from Wal-Mart for target shooting, and Golden Sabers for around the house. Recently I got some S&B and UMC, and they are not ejecting about 1 in 3 rounds. The Golden Sabers still work well, but not the other 2.

I know some pistols like some ammo better than others, but wanted to see if maybe some chamber polishing would help. So I took it apart and first checked to see how tight the chamber was with fired casings from each type, and fresh rounds of each type. I think my chamber seems to large (new rounds seem loose).

I took out a set of calipers and made some measurements:

S&B:
.484" Fired Casing widest part
.479" Fired Casing at the opening
.473" Unfired Casing Widest part
.470" Unfired Casing at the opening
.046" Rim thickness

Golden Sabers:
.481" Fired Casing widest part
.477" Fired Casing at the opening
.473" Unfired Casing Widest part
.470" Unfired Casing at the opening
.041" Rim Thickness


.483" inside wall to wall of the rear of the chamber. That seems loose to me.... Do I need a new barrel? (it is quite old).

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GitSome45
May 27, 2003, 04:57 AM
I found alot of help posted on "Gunsmithing & Repair", you might try posting this question on that forum...:)

JMHO,

Howard

1911Tuner
May 27, 2003, 07:54 AM
Howdy yzguy,

An oversized chamber won't cause an extraction burp. In
fact, a pistol with a worn chamber will often get the brass
out without an extractor even being there at all. I just saw
it happen yesterday when I broke a hook during a string.

While your chamber is a little worn, it's not far off the mark,
and since the .45 ACP is a fairly low-pressure round, it shouldn't
hurt a thing unless you are getting odd bulges at the case heads or ballooning on the sides of the cases.

It's likely that your extractor hook is either worn, or has lost
tension, and this usually shows up as a failure to eject or
weak ejection on the last round.

Try this:

Load a dummy round...or a live one if you are VERY careful...
and chamber it at full speed. Don't ride the slide into battery...
let it fly. Remove the magazine and slowly extract the round,
but don't let it touch the ejector. The round should droop slightly
at the front, but stay in place. Shake the gun a couple of times.
If it still stays, the tension is okay and the problem is the hook.

If the round falls down the mag well, setting the tension will cure it. Remove the extractor and stick it in the hole butt-first with the
hook facing left. Put your thumb against the middle, and hook your index finger over the front. Bend the extractor to the left a little. Not too much, just put a slight bow in it. Too much, and
the pistol will stop just sort of battery. Repeat the droop test
until the nose of the bullet just sags when the round extracts.
If the hook is good, this will cure your problems. The reason that
some ammo works okay is probably because it has a larger rim
diameter than the stuff that causes the gun to FTE...This has
the same effect as increasing tension. Set the tension to the ammo with the smaller rim diameter, and it should work fine,
as long as the hook is good.

Hope this squashes your bug,
Tuner

yzguy
May 27, 2003, 11:13 AM
Yeah, I was not sure weather to post it here or under gun smithing, but figured there are probably people who visit this one, that don't always check the gun smithing one (and this is not to much of a gun smithing thing).... and if it really should be there, it would probably get moved.

But in any event, I'll give the extractor checking/tuning a try. I just wanted to make sure my chamber was not shot before moving on to other possible solutions... :)

Nero Steptoe
May 27, 2003, 11:29 AM
I bought Wiegand's extractor tension gages and adjustment tool and have been terribly pleased with 'em. Of course, somebody who's done a zillion extractors probably wouldn't need the Wiegand tool, but would be able to "wing" it, as 1911 tuner suggests.

Kruzr
May 27, 2003, 11:52 AM
Sounds like extractor to me also yzguy. Take a look at this article by Bill Wilson on adjusting extractors. If you need to order a new one, Wilson Combat Bulletproof extractors have worked well for me.
http://www.m1911.org/technic2.htm

flinch
May 27, 2003, 07:12 PM
If the chamber is too large would the brass have some gas streaks or markings down it's side where pressure was escaping?

yzguy
May 27, 2003, 09:53 PM
the spent brass otherwise looks fine....

ok, I tried the extractor test with the S&B and UMC, and both fell right out into the mag well....

I slightly bent the extractor, and now it holds all rounds much better, without dropping them.

I should be able to make it to the range some time this week and see how it does.

Thanks everyone, I'll let you know how it does.

yzguy
June 3, 2003, 12:09 PM
All is well now!!!

Thanks to all for the extractor help!! :)

1911Tuner
June 3, 2003, 12:12 PM
Ahhhhh! Anudder satisfied customer. Music to me thirsty ears...:cool:

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