Hollowpoints are nosediving, FMJ's aren't

A second message from me. My M40 is an early gun, serial number in the 11-hundreds and I have no idea how many rounds any previous owners fired through it. I just recently bought it and cleaned it (but not removing the guts from the frame). Then I went shooting.

Two 12 round, brand new magazines and 100 shots no problem, using 165 grain full jacketed bullets. Then, I switched to the 165 grain Federal Hydra Shocks. The problems started.

Again and again, in the first 6 shots from a magazine there were 2 or 3 rounds that nosedived into the feedramp and stopped the slid. Once tapping the slide with knuckles was enough to make it close. After about 6 rounds, no problems. So what causes this kind of jam? I have old gun (maybe a weakish recoil spring?) and new magazines. Any thoughts on this?

Bart Noir

 

Well, all we know right now is that your M40 MIGHT not like Federal Hydra-Shoks. I say try at least two other brands of JHPs before worrying. Want to do this on the cheap? Well, just head to your local Wally World and pick up two different boxes of cheap JHPs they stock: Winchester White Box Personal Protection/ Defense ammo and UMC-Remington JHPs. I have tried the UMCs in 9mm and though dirty, they fed well and were very accurate.

If you find that these do not feed well then you might just try getting the Federal Expending FMJs. Navy87Guy bought some and seemed to like its performance in his M9. Hope this helps!

 

if your serial number is that low it might be eligible for the trigger upgrade if it hasn't had it.

if it's had 20K + rounds or so it should be due for new spring/guide rod assembly and or new extractor.

take the guts out of the frame and slide and compare everything to the examples in the maintenance tutorials here.

don't know what you paid for the gun or how much use or abuse it's seen, but if you bought it used w/out firing and the serial number is that low (indicating it was one of the first circa 1999) you might be looking at a tune-up.

USAsteyr has all the parts, and dennis (the gunsmith there who does warranty jobs) can tell you about the old and new triggers. Easy well to tell old from new is if the pin running through it is on the bottom third it is eligible for the factory retrofit, if it's in the middle it's had it.

IDPASteyr can tell you more about signs of wear and when what parts need replacing, at 80K rounds he is our round count champ.

That feedramp should look like a mirror and I've never heard of Hydrashoks not feeding. But some rare gun may not take one certain round that all it's comrades will.