Build Thread A 10.5” 458 Socom upper is finally in the works for me.

osprey · Aug 25, 2020

After building a 16" rifle upper several years ago and realizing what a versatile and devastating round the 458 socom can be, I finally got the nudge I needed to complete a 10.5" pistol upper build. I have actually been collecting parts for a year or so as I come across good prices, but the final pieces (barrel and bolt) have now been ordered. The nudge came in the form or the WA state game laws. I hunt several firearm restriction areas that specified the use of shotgun, bow, muzzleloader, or revolver style pistol only. This years regs I noticed the have included the use of semi auto pistols greater than 40 cal. This opens the door for a braced ar pistol in 458 socom. I have already successfully harvested a deer with my 16" socom with 500 gr maker subsonic expanding bullets and it was very effective. I probably will have to tweak my loads a bit for the shorter barrel but I will have enough time before hunting season. The barrel I will use is a stainless Tromix 10.5" fast twist. At 1:10 it will stabilize the big 500 gr Makers at subsonic speeds out of this short spout. Suppressed this would also make a great hearing safe bump in the night gun. I will update periodically as it comes together.

223to45 · Aug 25, 2020

Sweet. I like my 458. Still messing around with loads.

Next on the list is the Makers.

Ran mine is a 3gun event couple weeks back.

osprey · Sep 8, 2020

I finally found a free chunk of time and built this 10.5" 458 socom upper out and pinned it on the pistol lower where my 300 blk usually resides. It should make for a great deer/pig/bear/ you name it harvester at reasonable ranges. It handles much like a regular 16" carbine with suppressor on and meets the requirements for some of the firearm restriction areas I hunt. I can't wait to shoot it.