This is a proposal for a wildcat made from a 50BMG case. It is mostly based on a written description of one David White which I can not locate. I include his description. So what was not said was inferred by me. I just put a spin on it by adding a .264 bullet in a sabot. According to software, V0 could be in the vicinity of 4500fps while staying under 65000psi. Because of the severely rebated rim/extractor area, it will function through a standard action. The main advantage of this cartridge is it shoots flat on a 20cm vital area out to 500m.

Here is the original posts by DW:

“I have been building what I call “BOOMER” rounds for almost 20 years now. I use the 50 BMG case but I cut it back to a total length of 2.500 inches. I have a 7mm BOOMER, 308 BOOMER, 338 BOOMER, 375 BOOMER, 416 BOOMER and 458 BOOMER…

These rounds are all relatively short and fat, kinda like the WSM and B-R cartridges. They are all minimum body taper with a 60 degree shoulder angle….

Because of the cost and availability of actions that could handle a round like this, it has been quite limited. I have turned the cartridge case head down on these and built them on Pre-War Model 70’s and Remington 700 actions and everyone just seemed to fall in love with them….”


for one, I do NOT chamber for these particular rounds in a barrel less than 30″ in length! To me, it just doesn’t make sence and for the most part, most guys will go with a 34″ or 36″ barrel to help the cartridge achieve it’s full potential…

The velocity of these cartridges will run a good 400-500 fps. faster than what the Ultra Mags will and for the most part, 3-shot groups will run a consistant 3/4″ or less at 300 yards when fired from a bench. I tell the guys NOT to shoot more than three rounds at a time and then let the barrel completely cool down before it is fired again. Barrel “accuracy” seems to hold well for up to 1,000 rounds and with the barrel being as long as it is, sfter 1,000 rounds have been fired through it, you can shorten it 3″ and rechamber it and gain another 500 accurate rounds through it. By accurate, I mean being able to keep 3-shots inside an inch at 300 yards. Just me personally but when it starts going out side that, it becomes useless. I say this because I am a 1,000 yard “deer hunter” or shooter, whatever you want to call it and I demand extreme accuracy from my rifles..”

R 264

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