450 Bushmaster

[Troublco]

No problem. Let me know what you're looking for in the way of load data, and I'll see what I've got.

[DSB OUTDOORS]

Thanks!! I'll hit you up when I get my .458 build started! I have to finish the .450 Bushy first.

[ShooterJM]

Does the .450 require a new bolt carrier group? From what I've read (albeit not much) it almost sounds like all that's needed is the barrel.

[DSB OUTDOORS]

Does the .450 require a new bolt carrier group? From what I've read (albeit not much) it almost sounds like all that's needed is the barrel.

Hey ShooterJM.
I mainly built the lowers and a couple uppers, but I beleave thats correct!! They use the same upper receiver components for the standard .556 you just add what ever caliber barrel you wan't. Be sure to check the head spacing!! When you get it all together to save some headache. and to be on the safe side!! They do require special mags or if you have some xtra 223 mags lying around, you can get the mag followers, gut out the 223 mag and make you're own.

[ShooterJM]

Well, looks like I need to find a .450 barrel now....

[SideShow Bob]

I don't know about the .450 BM, but with the .458 SOCOM plastic mags don't work, there is a plastic tit on the inside of the plastic mags that hang up on the .458 round.

[meatman]

I don't know about the .450 BM, but with the .458 SOCOM plastic mags don't work, there is a plastic tit on the inside of the plastic mags that hang up on the .458 round.

FWIW, I think it's typically the Pmags with the anti-tilt rib down the front of the magazine that won't work w/o modification. You can actually shave the rib down, but it's a PITA. The SIG556 plastic magazines actually work pretty well w/o modification for the 450BM, plus you can stuff 10-12 rounds in there.

[Troublco]

Does the .450 require a new bolt carrier group? From what I've read (albeit not much) it almost sounds like all that's needed is the barrel.

In addition to the barrel, you will need a bolt for the .450 that fits the cartridge head. It's considerably larger than a 5.56 cartridge case head. My .458 SOCOM bolt looks like it has tinfoil around the outside due to the size of the case head. Best to get a barrel/bolt that have been headspaced to each other if you want to build your own. The .450 Bushy, as pointed out by DSB, does require proprietary mags; something the .458 does not (another factor in my decision to get a SOCOM). Sideshow Bob has a valid point about the PMAGs, these big rounds don't fit well with that plastic rib up front. But any metal mag, like GI, Brownells, C Products, and so on, will take SOCOM rounds just fine. If I remember correctly, you can get 7 SOCOM rounds into a 20 round mag and 10 into a 30 round mag.

[DSB OUTDOORS]

In addition to the barrel, you will need a bolt for the .450 that fits the cartridge head. It's considerably larger than a 5.56 cartridge case head. My .458 SOCOM bolt looks like it has tinfoil around the outside due to the size of the case head. Best to get a barrel/bolt that have been headspaced to each other if you want to build your own. The .450 Busy, as pointed out by DSB, does require proprietary mags; something the .458 does not (another factor in my decision to get a SOCOM). Sideshow Bob has a valid point about the PMAGs, these big rounds don't fit well with that plastic rib up front. But any metal mag, like GI, Brownells, C Products, and so on, will take SOCOM rounds just fine. If I remember correctly, you can get 7 SOCOM rounds into a 20 round mag and 10 into a 30 round mag.

Thanks Troublco!! Not sure how I over looked that one!! Too many

[SideShow Bob]

If I remember correctly, you can get 7 SOCOM rounds into a 20 round mag and 10 into a 30 round mag.

And 3 rounds into a 10 round magazine, 4 if you force it.