My FM HiPower only shoots 124 gr ammo? Is this weird?

[Dorrin79]

So, an update on my FM Hipower.

Following the advice of our esteemed experts, I removed the extractor and cleaned the extractor channel.

I then got some different ammo weights and brands to try in it.

Results?

Still jammed 2-3 times per mag with 115 gr WWB.

Jammed EVERY SINGLE SHOT with 147 gr FMJ. (I only tried one mag's worth)

Fired 50 rounds of CCI Blazer 124 gr, 50 rds of UMC (or PMC?) 124 gr, and 2 clips of 124gr +P EFMJ with no failures.

At this point I am forced to conclude that my gun only feeds/extracts 124 gr ammo.

So, I ask of you, what the heck? Is that normal for mil-surp firearms? Other than my MKII .22lr, this is the first ammo-sensitive gun I have encountered.

 

[Hellbore]

Perhaps a lighter recoil spring would solve your problem?

Also, is the gun broken in and properly lubed? I wonder if it needs smoothing out...

Just guesses, I'm new to guns...

One thing I was thinking about was that you said it was mil-surplus. I believe 124 gr is used in the military exclusively isn't it? 9mm NATO? Maybe even heavier? I'm thinking that the recoil spring may have been replaced with a heaver one at some point or the gun otherwise tuned to use 124 grain exclusively.

Also I read that the WWB ammo has a different angle on the rim on the back an has been known to jam in several guns. Did you try any other brands of 115gr ammo yet? (not wolf either )

 

[Sean Smith]

Jammed on 1 brand of 115gr is not = won't work with any 115gr.

Suggest that a heavier recoil spring is more likely to make it feed than a lighter one, but that neither addresses the root cause of the problem.

 

[tlhelmer]

That is unusual, but at least your gun functions with the best overall weight (IMHO) 9mm bullet. Does is handle 124 gr. +p ammo as well? I prefer the Winchester 127 gr. +p+ Rangers, but I could live with 124 gr easily.