Why is my 1911 denting brass/FTF'ing?

[N183CS]

I bought an older SA GI 1911 at a pawn shop a few months ago and have been having issues with it. It is one of the US made pistols. It shoots beautifully when it works but when it doesn't it can be frustrating. It likes to jam half way into feeding a new round. It will fire fine and every now and then the new round will half-feed and get hung up, it appears the extractor isn't springing out of the way enough to let the new round seat in the slide. It will do it maybe 1 time out of twenty. I have tried bending the extractor back to try and relieve some of the tension on the shell and also switched to a heavy Colt commander spring to give it some extra power in seating a round. My gunsmith filed and polished the extractor groove to try and ease the tension on the shell but so far nothing has helped. I have pushed the extractor back by hand and it moves freely and springs far enough out of the way to clear the round completely when feeding. Before I break out the new parts shotgun, is there anything you guys can think of that I haven't covered? I have tried American Eagle, Magtech and Remington 230 grain ball ammo and all have shown the same issues. I polished the feed ramp, chamber and all slide and frame surfaces that showed frition wear with a dremel and metal polish. I keep my 1911 clean all the time so I know it isn't fouling up. My mag is an aftermarket 8 round stainless unit with the factory SA 7 round spring and follower. The SA mag had a crack causing it to jam in the mag well and the 8 round spring in the aftermarket mag didn't have the power needed to hold the follower in place to lock the slide back. Since mixing and matching parts the slide has locked back every time and my mag capacity has been limited to seven rounds.

I have noticed all my fired brass has a pretty substantial dent showing as well as abrasion marks where the dent is. My gunsmith said this is because the GI spec 1911's have ufluted ejection ports but I can't quite picture how this would cause the dents. I'll try to post pics of the issues I'm having soon.

[Fang]

I eagerly await the arrival of pictures to aid in diagnosis.

[N183CS]

I took a few pics of the pistol and fired brass. Here they are. **Disclaimer: I removed the firing pin and spring before loading the round to show the half feed**
http://inlinethumb16.webshots.com/31567/2922819860055386387S600x600Q85.jpg (http://good-times.webshots.com/photo/2922819860055386387RMjwxt)
http://inlinethumb06.webshots.com/34565/2741470420055386387S600x600Q85.jpg (http://good-times.webshots.com/photo/2741470420055386387ruGufh)

The brass photo isn't the best but it shows the dents pretty well right near the edge of the cases. There is a v shaped groove about 1/32" deep and maybe 1/8" long, I can't figure out what it could be rubbing on. My only guess is that the magazine is releasing the round too soon, allowing it to free float for a small portion of its travel before it engages in the extractor groove, causing it to become misaligned with the chamber. The way I recreated the jam was to wiggle the round around until it jammed and when I slowly released the slide there was a brief spot where this happened then it jammed. I'm wondering if the case is coming out at an angle and hitting the top of the chamber on its way out. If it is a magazine related problem, like all the other problems I've had with this gun have been, whats the best replacement mag I should try?

Edit: After looking at the photo, I can see where the shell is getting dented. The 90 degree notch on the barrel, straight up from the trigger on the right side looks suspiciously the same shape as my dents. I'm leaning towards the extractor being the cause of this one.

[Fang]

The brass denting is fairly common in 1911s and usually indicates that the shell is not getting schucked completely clear of the ejection port before the slide starts coming forward. This in turn happens either because the slide is not coming back with enough vigor, the extractor is either grabbing the rim too hard or not holding onto it enough to let it be reliably kicked out by the ejector, or the ejector is not smacking the cartridge hard enough. (The ejector not hitting the case hard and the slide not coming back vigorously can be the exact some thing, but in some cases the ejector can be loose or too short.)

First, though, let's look at the jam, in case the same thing causing it is causing the case dents. It's hard to tell by the photo, but that jam could either be stem bind (where the extractor binds on the rim of the round and prevents the base from sliding up the breech face and into battery) or a three-point jam. A three-point jam is where the barrel is forced up prematurely by the bullet hitting the barrel ramp or roof of the chamber in the wrong place; when the barrel rises, it jams up on the slide, the cartridge wedges into the chamber, and the base of the cartridge gets caught under the extractor.

It's easy to tell the difference between stem bind and a three-point jam: With stem bind, pushing or smacking the back of the slide can force it into battery. With a three-point jam, it ain't going nowhere.

Questions for you:

1. When your 1911 jams, can you push on the back of the slide and force it into battery?

2. What kind of magazines are you using?

3. Are the jams specific to any type of ammunition?

4. Do the jams happen more often with some types than others? Do they occur more often at certain points in the magazine (e.g. within the first three rounds, always on the last round, etc.)?

[B4Ctom1]

2. What kind of magazines are you using?

THIS

as lame as it sounds, almost every problem I have ever had with a 1911 that wasn't caused by me installing lame or stupid parts, was remedied by the use of Chip McCormick magazines. There is another brand that others like as well.

This simple $13 solution along with extractor tuning has turned even the saddest pos 1911 I own into the most reliable 1911 I ever imagined it could be.

After all I the time I wasted, I will never use a different magazine.

[N183CS]

Well the Chip Mccormick mag seemed to have cleared everything up. It is still denting brass, but I can see where it is hitting on the ejection port now because it is leaving a mark. It's right where the metal would have been removed had my gun been a flared ejection port model. I've decided to sell the gun and get something with more capacity, I am tired of loading mags all the time at the range.

[larryh1108]

Some interesting reading on the 1911 feeding issues.

http://forum.m1911.org/showthread.php?t=9178

http://how-i-did-it.org/magazines/

[Fang]

http://how-i-did-it.org/magazines/

Heh, that's my article. But it was thanks to 1911Tuner and Clinotus here that I wrote it.

[larryh1108]

Yes, you had very nice and qualified help but your way of putting it to words for the average Joe to understand is priceless! This is bookmarked for me and will forever be in my frequent review and re-review. You have at least 1 fan in me for your ability to "talk" to us. I personally thank you! You have fueled a passion I already had in the 1911s and taken it to another level. Mt gratitude to you is enormous! You made a difference in my life. :)

[Fang]

That's awfully nice of you to say. Glad that my little article could prove helpful.