I am considering a 45 caliber AR-15 upper that will be compatible with heavy 45cal pistol bullets and will have enough power to reliably take big feral hogs at 200 yards without excessive recoil for multiple rapid-fire with a "herd" of those destructive beasts in my pasture.

Is a 45Socom a good choice?  How about alternatives?

TIA,
Sid

458 Socom will get the job done but uses .458" pills.  I went with the 450 Bushmaster because l aready had a shitload of .452" bullets for the Casull and Colt.

I think you meant .450 Bushmaster.  You didn't say which .45 pistol bullets you wanted use.  Some bullets for the .45acp can be used while others not so much.  It has to do with . 45acp bullets being designed to work at much slower speeds than the bushmaster has.  Also .45acp bullets are .451" and the .450 bushmaster are .452".  It can work, but there's that.  

If you're talking .452"  .45 colt or Cassull, then yes, you can use some of those bullets keeping in mind the OAL differences and such.  

The list of "thumper" calibers are from smallest to largest - .350 Legend (newest to the group and I don't know if there's a semi auto platform for it), .450 Bushmaster, .458 Socom and finally the big boy, the .50 Beowulf.  Any and all of these will drop tough critters with relative ease.  There's also another newish option called the .300 Hammer or something like that but I'm not familiar enough with it to give info on it.

I chose a .50 Beowulf because I loved the idea of owning a "baby 50 cal" and ammo is usually the least expensive of the group.  The .458 Socom usually has the most availability of ammo.  The .450 Bushmaster is probably the least used of the group mainly because most people who want a .45 caliber thumper choose the Socom.

I don't know if you are looking for 45 acp type guns, or If you reload and/or want to shoot heavy cast 45 bullets the CMMG 45 Banshee will safely shoot 450 SMC (and 45 super).

So that's a 255gr bullet at up to 1300fps.  Loaded ammo is pretty hard (impossible) to find, but you can find 45 super easy enough or buy 450SMC brass online.

I found this on one gun mag website:

"A noted handgun expert wrote that his wife has used a .45, 260 grain, lead Semi Wad Cutter at 900 FPS to take five Mule Deer and his son has used the same load to take a nice Mule Deer Buck at 90 yards. Those bullets were all fired from a .45 caliber revolver. He said this load will go through an Antelope or a Mule Deer lengthwise at 100 yards. I conclude that a .45 Super 255 grain lead flat point or SWC at 1,075 FPS will do the same or more."

There are plenty of 350 Legend AR-15 pattern uppers out there ready to pin on and go.

Where are you finding that 50 Beowulf is usually cheaper than 350 Legend or 450 Bushmaster? I've never found it for less than what I can get those cartridges for. 450 Bushmaster hangs right around $1.50, slightly less than what I typically find 50 Beo. 350 Legend can be had for a whopping .60-ish cents a round. If you found 50 Beo for that, please share!!!!!!