How to make a Ruger 10mm?

[November]

Anybody know if it would be possible to convert a Ruger P91 or P94 in .40 to 10mm just by reaming the chamber? Would the P91 be the stronger candidate? Can the Ruger take the extra pressure and abuse? Any mag issues? Thanks for any info.

 

[lee n. field]

Any mag issues?

length. The 10mm is about 1/10th inch longer than .40S&M. Will stock .40 magazines accomidate 10mm rounds?

Otherwise, interesting question. The P90 is the gun supposedly originally designed for 10mm. That would be the prime candidate, but I haven't ever read of anyone converting that.

 

[November]

Well, here's the idea: I've got 800 rounds of 180 gr. lead round nose 10mm target ammo (American Eagle brand, pretty tame stuff) that's too dirty for my Witness 10mm that I like to run with DoubleTap Ammo's 180gr JHP load. I don't mind experimenting on my guns (within reason), so I figure if regular 10mm ammo won't fit the ruger mags I'll just put in stronger recoil springs (I'll check with Wolff), ream the chamber and "shave" some of the lead from the face of the bullet until it fits in the mag and burn up the rest of this target ammo. I can always go back to .40 later. I think the slide of the P91 may be heavier than the P94, so maybe that would be the way to go. Also, I believe the P90 was originally designed to chamber the 10mm, but that never happened, so they re-tooled for .45acp. I think the P91 is identical to the P90 other than caliber and grip-frame width. Anyone know for sure? I guess I've always heard/read/believed that Rugers are "built like a tank", so I'm thinking it may be possible to do this. You're probably saying, "why not just sell/get rid of the ammo"? That's probably the sensible thing to do, but this seems like a cool project and I've got extra barrels. Any other things to be aware of?

 

[November]

Well, it looks like 10mm ammo won't fit in a Ruger .40 mag without some serious bullet shaving. That leaves out the P94 or P91 frames. It looks like it WILL fit in a .45 mag, though. Hmmm....maybe a P90 frame/mag with a reamed P91 slide/barrel combo (if it'll fit)? Wolff sells P91 springs up to 24 pounds so maybe it's still possible.