Since I am not really impressed  with 300BO on deer,  and my wife has stolen  my grendel,  I am exploring  other calibers.
Faxon has a Black Friday deal on 10.5" 458 socom barrels, and now I  am thinking thumper.
Anyone have a 458 socom pistol AR? What is your thoughts? How is the recoil? A little searching  tells me the brass ,bullets and build parts are available,  unlike anything  grendel.

Go with a TROMIX barrel and bolt* or you stand a good chance of regretting it.  Recoil is stiff but completely manageable in an AR pistol.  I have AR pistols in 6.75”, 8”, and 10” as well as a 14” Striker bolt action pistol and with normal deer loads, 325 gr. and under, even hot loads are easily managed if you have shot a .44 magnum.  .458 pistol loads with hot 500 gr. loads can be a bit hard on the wrist but no worse than a .454 Casull or .45-70 Contender.  

*Most .458 barrels made by recent jump on the bandwagon makers do not make their barrel extensions properly and are completely lost when it comes to bolt modifications.  If you buy a late comer barrel and bolt and run into feeding problems, no, it’s probably not the mag.  A properly made barrel and bolt will function 100% from the get go with Lancer or GI style aluminum or SS mags of quality manufacture.  PMags can be a problem if loaded with spitzer bullets or with bullets that have a COAL of 2.250” due to the rib down the front of the mag.  The .458 S came out well before the Pmags and Magpul did not take into consideration the .458 S when making the Pmag.  Some of these problem rifles can be made to work with mag mods but a properly made barrel and bolt will not need any mods to the mags.

Also, start with standard CAR or Rifle buffer and springs.  On a short barreled pistol you may need a HB but don’t go there until you find a reason to do so, such as extractor swipes, ejector swipes, or bent rims.  In the .458 S, those swipes are NOT from over pressure but from timing, which a HB will correct, IF you have that issue.

Don’t forget to have the ejection port opened if using a standard 5.56 upper.  Paladin Machine Shop Service can do this quickly and cheaply, as well as true the face of the receiver.  Tp555-work(at)vfemail.net
The port cover will still latch shut also.

By the way, a stainless steel 10.5” barrel AND bolt from TROMIX is $359.  It will work from the first shot providing you build it correctly.  It does not take many shots of factory ammo to eat up any savings you think you have made trying to get a lesser barrel and bolt to function properly.

Just remember:
Enlarged ejection port.
Properly placed gas block.
Standard buffer and spring.

Even a TROMIX barrel and bolt won’t work if you screw the pooch during the build.

Holy shit, that is fantastic  information,  thank you.I do have a 454 , and a 45/70, so have experienced  some recoil. I will definitely  look at tromix.