Could FTE be magazine related in Smith 645?

[Capt. Charlie]

I posted this several weeks ago up in the semi-auto forum and got very limited response. I probably should have posted it here to begin with, and it appears the mods missed my request to move it here, so here goes again. I don't like double posts, but I need answers. Here's the problem:

I have a S&W Mod. 645 that, prior to this, has performed flawlessly for 2 decades. The original magazines were dropped one too many times and I had to replace them. I bought six "Pro-mag" magazines, which is supposed to fit the 645, the 6045, and so on. Now I hadn't fired it for a few months, but when I put it away, it was working great. The first time I used the new magazines, every other case has failed to extract. I've inspected and cleaned under the extractor, and I can't see any problem there. Could the new magazines cause this or is it a coincidence and I have another problem?

[michael t]

I would think a extractor problem. But from my experiance with Pro mags I wouldn't walk across the street for them. If they were giving them away by the case Go find a good factory mag and see what happens.
I am not a gun smith nor do I ever plan on being one.

[J.D.B.]

Midway sells the factory mags. They are pricey, though at $30.00 a copy. At some point, Smith changed all the .45 mags to a set-up they call "accu-glide" as I recall from conversations with their rep. The feed angle is critical he told me, and that was the biggest change on the current mag. I had to alter my slide stop on my 745 to keep it from eating the followers (per factory instruction) and they are flawless since then. Try one new factory mag and see if the trouble stops or stays with the Pro-mags. As posted above, my experience with Pro-mags was that they were outright garbage(the clowns were selling mags cheap for Glocks. No metal lining in them, so when they were halfway full, the rounds would come "fountaining" up out of them. They took them back and refunded my money, no questions).
Josh

[DnPRK]

Describe the FTE.

Does the case remain in the chamber?
Is the case extracted from the chamber but fails to clear the ejection port? Stovepipe?

[Capt. Charlie]

The case remains in the chamber. At the most, it might extract 2 or 3 mm.

[4V50 Gary]

Check the extractor hook and the extractor spring.

[Capt. Charlie]

The hook is clean and free of burrs or rough edges, and pivots smoothly under extractor spring pressure. I'm stumped.

[4V50 Gary]

It extracts every other case, right? So the problem is intermittent. Hyper-function? The action is working faster than the normal speed for extractor to do its job. Have you changed ammo or is the recoil guide spring now too weak?

Compare the lips of and old mag to your new after-market Pro-mags. I'm wondering if they're causing underfunction (opposite of hyper-function). The mag lips may be so high as to cause drag. Alternatively, the spring tension of the mag spring may be too strong and thus it slows down the rearward motion of the slide. This is one reason why I don't like aftermarket magazines. Unless they build them to factory specs, they may limit the range of ammo or conditions under which the gun will function reliably.

[Capt. Charlie]

...is the recoil guide spring now too weak?

Now THAT is a real possibility Gary! This weapon is around 20 yrs. old with a lot of rounds through it, and the spring is the original one. It had been sitting in the safe for over 6 months before I got the new mags. Maybe it was just time.

Except for higher quality 1911 mags, I don't care for the after market mags either, but as was stated below, factory mags for this thing are rarer than feathers on an alligator. I'll try to see if it's hyperfunctioning or dragging on the mags. Other than that, it's off to the 'smith I go, and he's backed up about 6 months on work .