Something new is coming next year from Big Horn Armory:  The AR500 in .500 Auto Mag.  Billed as “the most powerful short range semi-auto in the world”, the ballistics on the new cartridge are most impressive if confirmed. Out of an 18″ barrel, numbers for some of Underwood’s and Doubletap’s loads well exceed ME for the .458 SOCOM and even Brenneke Black Magic Magnum Slugs.  These massive rounds aren’t so slow, either.  Many are moving along at over 2200 fps, not bad for 350-400gr bullets.  For comparison, this somewhat comparable to .458 Win. Mag/375 H&H Mag-level performance at short range.

The diameter and OAL of the cartridge requires it to be chambered in a AR10-based platform, so this power comes with a premium in size and possibly weight over big-bore platforms compatible with AR15 lowers.  Magazines that ship with the rifle with hold 10 rounds.  At first glance, the new rifle and cartridge do not appear to use a “compact” AR10 lower. No word yet on whether we will ever see a massive semiauto handgun chambered in this round.  I have reached out to BHA for more details on the manufacturing status and projected availability of the cartridge itself.  This article will be updated when that information becomes available.

Per Big Horn Armory:

Price: $1999.00

Introducing the Big Horn Armory AR500 semi-auto rifle. Chambered in the 500 Auto Mag cartridge. It is the most powerful short range semi-auto in the world. Based on an AR 308 platform, it is capable of putting 50 BMG power on target with three trigger pulls with very reliable extraction.

The 500 Auto Mag is a rimless 500 S&W Magnum. A very versatile cartridge, It can handle anything from prairie dogs to pachydemrs to Peterbilts. Truck stopping power in a platform weighing less than 10 pounds.

1:24 twist 18″ Barrel, adjustable gas block, full picatinny rail, M-Lok forend, adjustable buttstock, flash suppressor, no sights, 10 round magazine, hard plastic case.

Pre-orders are being taken today for delivery in the first quarter of 2018. $600 deposit required.

500 S&W Loads			BHA Carbine
Factory Loads	Factory P/N	Bullet Mass gr	MV 18″	ME 18″
Buffalo Bore 400 JFN	18A	400	2003	3563
Buffalo Bore 440 LFNGC	18B	440	1808	3193
Buffalo Bore	18C	440	1498	2192
CorBon 275 DPX	HT500SW275	275	2085	2654
CorBon 400 JSP	HT500SW400JSP	400	1936	3329
CorBon 440 HC	HT500SW440HC	440	1844	3322
CorBon	HT500SW500HC	500	1692	3178
CorBon	HT500S500JHP	500	1429	2267
CorBon 275 DPX Special	HT500S275	275	1334	1087
Federal Barnes 275 XPB	P500XB1	275	2238	3058
Hdy 300 SST/FTT	9249	300	2328	3610
Hdy 350 XTP	9250	350	2133	3536
Hdy 500 FP/XTP	9252	500	1536	2619
MagTech 400 SJSP Flat	500A	400	1850	3040
MagTech 325 SJSP Flat	500B	325	2099	3179
MagTech 275 SCHP	500C	275	1917	2244
MagTech 325 FMC Flat	500D	325	2077	3113
MagTech 325 SJSP LL	500L	325	1422	1459
Ultra 325 JHP	500SW1	325	1510	1645
Ultra 440 Cast	500SW2	440	1384	1871
Ultra 375 CastPro	500SW3	375	1506	1888
Underwood 700gr HCLFN	741-20	700	1591	3934
Underwood 350gr XTP	348-20	350	2301	4114
Underwood 350gr Xtreme Penetrator	839-20	350	2241	3903
Underwood 440gr HCLFN	749-20	440	2031	4030
Underwood 500gr HCLFN	744-20	500	1911	4054
Underwood 500gr XTP	349-20	500	1831	3722
Win 350 JHP	X500SW	350	1469	1677
Win 400 PTHP	S500PTHP	400	1970	3447
DoubleTap 400 WFNGC	400WFNGC	400	2281	4621