View Full Version : 1911 Magazine Alignment
March 1, 2009, 06:37 PM
After some time at the range today, I started comparing some things between my Sig GSR Revolution and my Colt LW Commander.
First thing's first, the Colt feeds hollowpoints with no problems at all. The Sig tends to choke on hollowpoints. The Sig also has a tendency to bash the bullet a bit on the feed stroke, even shortening cartridge OAL a hundredth or two if you pull it out and measure before/after.
With the slide locked back on both weapons, I inserted magazines into each gun's respective mag well. I used Colt, Kimber, Wilson, Marlin and Novack magazines for this series of tests.
With every one of them, the magazine had a lot of wobble forwards/backwards in the well of the Sig, and very minimal wobble in the Colt. I can see exactly how the slide causes the mag to tip forward during the feed stroke, mashing the bullet nose on the frame.
How can this be fixed?
March 3, 2009, 10:05 AM
But what I did was swap around my mag release assemblies (I have about half-dozen) until all four guns (one 9x19, one 40 S&W, two 45 ACP) worked right.
So you might try a different brand of mag release; might start with a Nowlin.
April 15, 2009, 06:29 PM
I pulled the magazine catch. It appears to have significant peening.
Replaced with an Ed Brown magazine catch.
My Sig GSR allows for the magazine to float ~3/16 of an inch when fully inserted. Conversely, my Colt Commander allows the magazine to float less than 1/16 of an inch. The Colt holds the rounds up higher for the slide to grab them. The Sig ends up having the bullet nose slammed against the feed ramp.
I'm willing to bet that within 300 rounds, my nice new Ed Brown mag catch will exhibit the same peening as the original mag catch.
For grins, I pulled the mag catch from my Colt and swapped around. No matter which of my three mag catches was in the Colt, it did fine. No matter which of my three mag catches was in the Sig, it held the magazine too low and allowed it to wobble forwards and backwards.
I think the slide is barely grabbing the round and tilting the mag and round "downwards" and slamming them against the forward face of the magazine well, magazine catch and feed ramp. This is causing the peening on the original catch.
If I teacup the pistol, it obviously doesn't give me any grief.
Will this end up possibly being a bad frame? Either a bad cut for the magazine catch hole, or bad mag well geometry?
April 17, 2009, 01:05 AM
It seems you already have one answer to your dilema.
The various magazines you have tried all are loose in the Sig, approximately 3/16".
Of course this places the magazines too low in the pistol to reliably feed.
As you also said "if I teacup the pistol it works well"
I'll assume you mean resting the pistol on the magazine, thus holding the magazine into the proper position.
From 1911 prints, the magazine release hole (.315" dia.) is 1.095 below the slide stop hole. The slide stop hole is .450 below the rails.
Therefore you can measure the mag release hole to the top of the rails with a caliper.
It should measure 1.095" plus .450" minus (1/2 .315") equals 1.3875".
I suspect this dimension will measure something significantly greater.
Of course you can compare your commander to the Sig.
Remove the slides from both pistols. Insert a magazne into each pistol.
Compare the relative height of each magazine. The Sig will be riding lower unless held up into position, ("teacup").
Is it possible your model uses a Sig specific magazine?
April 23, 2009, 01:30 PM
JMB: I wish I could take the measurements you described, but I shipped the pistol back to Sig yesterday.
Is it possible your model uses a Sig specific magazine?
I have the original 2 mags that came with the pistol... Novak magazines. Sig has no proprietary 1911 magazines. Those Novaks (and every other mag I have) work great in my Colt and in my Camp 45.
I also admit I exagerated on the drop distance of the magazine... It's not 3/16 but it sure looks huge when it is allowed to float freely. I measured with my caliper and it is approximately 0.050". The Colt is about 1/3 of that, roughly 0.015".
Also, the mag release hole is "keyed" with (for lack of a better term) a lower bout and an upper bout like a guitar. The lower bout (opposite the latch screw, the smaller one) has some rotational play when inserted into the frame. Tugging up/down on the magazine shows the catch itself has some degree of play because it is not held in place by what I assume to be a correct frame cut. This play is evidenced by the Sig mag catch, the Ed Brown one and the Colt one when inserted into the Sig frame, but none whatsoever when any of the 3 are inserted in the Colt frame.
I think my frame is boogered.
April 23, 2009, 09:18 PM
.050" error in the frame is well beyond tolerances.
I suspect the fine folks at SIG will recognize that and do whatever is necessary to resolve your problem.
I have an AMT which suffers from the same type error of .030".
As you already know, this type of error leads to feed jams.
Please keep us up to date with your results from SIG.
April 30, 2009, 09:32 PM
Got my 1911 back.
Sig just screwed it up worse, so it now exhibits the original problem from 2 years ago as well as the OAL smashing and occasional failure to feed.
They replaced the extractor (which I didn't ask for). Now the nose of the bullet gets stuck on the top of the chamber... probably because the cartridge isn't sliding underneath the extractor easily. The spring tension on the external extractor is higher than it was before.
I'm REALLY irate right now.:mad:
1. Smashes the bullet nose hard against the frame ramp if you don't teacup the magazine.
2. Shortens cartridge OAL.
3. Fails to reliably feed hollowpoints.
4. Drops the magazine in the well 0.050".
It started up with the old drama from 2007 where:
1. It smashes the ever loving heck out of the brass, nearly piercing the case somehow on the bottom about 0.250" above the case head.
2. It "high centers" on the feed ramp and shoves the bullet nose into the top of the chamber, probably because the rim can't get under the extractor properly.
I'm going to talk to a gunsmith here in town about it. I'm really getting frustrated.
May 1, 2009, 11:43 AM
Just heard back from Sig.
They are going to replace the gun entirely.
Bums me out a bit since it was a limited edition... but then again, it obviously ain't working right.
May 3, 2009, 10:54 AM
I suggest taking that as 'good news'.
I sincerely hope your next is perfect.
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