What pistol calbers can be had in uppers?

I just bought my first AR-15(16" Bushmaster), and I'd love to find a 380 upper for it, if there is such a thing.

Refer to Olympic Arms, they have the largest selection of pistol caliber,,, 380 is not one of them.

Colt pattern (RRA, ASA) is the other choice, with 9mm being the only selection, though you can possibly go a couple other caliber, but would require some machine work.


Why 380, nothing to gain in a longer tube, may not have enough "UUUMMPH" to cycle the bolt in an AR.... Try the "rimfire-pistol caliber" forum.

Thanks SBR7_11.

The reason for a 380 is that I have a 380 pistol. I'd also likely use it on a called in fox this coming winter.

I'll try the other forum. I didn't notice it when I posted this, or would've asked it there instead.

I just checked my .380 ammo. I am surprised to hear after all these years that what I thought was centerfire turns out to be rimfire.Hee. As far as a .380 upper is concerned, why not? .380 is 9mm short. Power-wise you probably wouldn't cycle the regular AR action and figuring out the timing, carrier weight, spring and buffer would be a challenge. So what? For people who are interested in novel calibers the challenge is as much fun as attaining the objective. Why else would there be a .50 BMG AR upper available? If your not inclined to spend big bucks and a whole lot of skull-skill woof and warp trade up your .380 for a Kahr PM-9 9mm, it's smaller then a lot of .380's and most gun savvy people see 9mm as the very bottom of the stopper list. Then go for a 9mm AR-15 and enjoy. Good luck.