Bishop Ammunition new biggest AR-10 caliber

Bishop Ammuniiton of Antelope, CA announced on their Facebook feed today that they are going to be having a custom caliber done up for a line of customized rifles they are building which, according to their statement will be - The largest caliber loaded on a necked case available for the AR-10 platform. I take this to mean an oddball caliber upper, such as .458 SOCOM but larger. They actually said that their new caliber will make the .458 look puny, and so I am presuming something along the lines of a .50GI bullet loaded into some oddball large necked case to appear like a scaled up version of a .458 SOCOM, albeit with a more drastically rebated rim to match the .30 cal bolt face, unless they are talking a custom bolt as well, which is essentially then not an AR-10 platform at that point. Who knows.

Has anybody seen any of their pistol ammunition, specifically
.40 S&W and .45 ACP, both “new” ammunition and “remanufactured”

John Moss

Here it is the .475 Bishop Short Magnum:

And with a MSRP of only $189 per a box of 20 rounds.


Seriously? that puts them in the realm of prices along with the African big game stuff like .470 Nitro, or .404 Jeffrey, and well over something like the .458 HAM’R. Not exactly fast-moving price territory for a new caliber.

heck three boxes / 60 rounds of that ammunition or a new AR. Ummm I wonder which I should buy for the most fun.

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My thoughts exactly… I suppose I don’t see the gain in a fancy new AR-10 caliber

I think I have the riddle of their ammo pricing figured out. It looks like they had Roberson Cartridge doing custom cases for them with the BAM headstamp, and these cases by Roberson are turned out of solid brass, making them relatively very pricey. The price shown on RCC’s website is $5.22 per case for this caliber.