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Odd Failure to Feed

1563 Views 3 Replies 2 Participants Last post by  Dan Burwell
The last two range sessions with my MP9 have been plagued with a strange failure-to-feed malfunction. Maybe 10-12 times out of 800 rounds, the slide fails to completely return to battery. The cartridge seems to hang up just about 1/8" short of full lockup. Tapping the magazine or bumping the rear of the slide will not cause it to close, but all of the problematic cartridges chambered properly when I removed them and reinserted them into the magazine.

So far I've only fired this pistol with my handloads, 147grn. Zero JHPs over 3.x grains of Titegroup, mixed cases, Federal primers. I'm perfectly willing to accept that my handloads are the problem, but I saved a couple of bad rounds and mic'd them, and they're all fully in spec (C.O.A.L. within 5 thou of 1.100", etc.)

Any ideas?

- Chris
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Don't suppose you are running a light recoil spring or have a boat of rounds on your factory spring? I had asimialr issue when I was running a an 11# spring. Seemed like it was border line strong enought to bring thr gun into battery any little debris would stop it short. Usually when it happened to me I could just bump the slide and it would close.
As a matter of fact... Yeah, I'm running a 13# ISMI spring. I'll stick the factory spring back in there and give it a try.

- Chris

If you want to keep the 13# spring you may be able to use a reduced power striker spring. I really don't like using them as it makes the trigger a bit creepy and can cause light primer strikes (it doesn't in my gun, but I have some pretty screwy striker modifications that may be keeping mine running).

If the recoil impulse is more important to you than the trigger feel this may be what you need.
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