Thumper

[Dave]

Haven't seen it discussed here, but has anyone shot or know of anything beyond the Bushmaster website about their .450 upper nicknamed the thumper? Their site says it is designed to take down all north american game and is accurate to 200 yards. I only ask, because I am building a 20 inch A2 clone on a shadow ops lower that I want to use for longer than 300 yard shooting, and I had considered a .300 blackout upper to use for hog hunts. But the idea of this .450 cartridge has me wondering if it might be better to use for a bigger range of game than the .300.

[MarkCO]

Sorry for the delay, just now saw this.

The .450BM (Thumper) is kind of a niche cartridge. While I personally prefer it to the .458 SOCOM, it does have it's little idiosyncrasies. While there is a website dedicated to the Thumpers (http://450bushmaster.net/) here is my personal opinion based on your post.

Look elsewhere if you want to shoot over 300 yards at game. The .450 is a beast, and insanely accurate, out to about 200 yards. I can still hold 3" groups to 300 yards, but the rainbow trajectory starts in the late 200s. For White Tail and hogs, it is a great round to about 300 or so. Bear and Elk, probably limited to 200 yards due to energy.

The .300 BO with supersonic rounds has about the same energy at the muzzle as the .450BM has at 300 Yards. The .450BM would be far superior to the .300 BO for hunting medium sized game, but with the "longer than 300 yard" desire you have, you really need to look at a 6mm to 7mm diameter projectile if you want to stay with the AR-15 platform. I have both, and you are certainly more than welcome to try them in comparison sometime.

[Colorado Osprey]

If you truely want a 45 cal in a performer, there is a gunsmith Mike Milli aka Dtech who excels and is a pioneer in off caliber AR-15's.
He will make you a WSSM necked up to .458 using rifle bullets instead of the .451-.452 pistol bullets of the Bushmaster.
Performance will be in excess of the 45-70. He also sells a .358 version to have less of a rainbow trajectory at longer ranges. Case capacity is performing to the 30-06 size case equivalent while still fitting in a AR-15 magazine. Olympic Arms did the initial research on the .458 version cartridge but never marketed it.
The 30 cal version is out performing the 30-06 and is just shy of the 300 Win Mag and makes the Black Out look like a BB gun.

His WSSM versions are available in .224,.243,.257,.264,.308, .338,.358 and .458 bores.

Mike is highly sought after and has a great following in the hunting AR community.

[Dave]

Thanks for the advice. For big bore on an AR I decided on .458 since all big bores are niche, but with .458 there seems to be a bit more interest and I can use regular mags, which is also why I'm still considering .300 blk, but might swap my interest in it to suppressed shooting. For longer range and big game hunting I have a Savage in .300 win short mag, the big bore AR would be for medium game at sub 200 yard ranges like deer or speed goats. The 20 inch 5.56 build is for coyotes/small game and testing my limits with a smaller round. Eventually I'd like to have a longer range medium or even big game AR, but I have to go in steps, but I'll keep Dtech in mind for questions when I get there.

[MarkCO]

You going to buy or build? Feel free to drop me a note if you have any questions. There are several .450BMs in CO, but not what I would call common.

[spyder]

I have no experience with the 450, but I know the 458 is fun! If you think about going the 300 route, look into the 7.62x40, that's my next build....

[buckshotbarlow]

CO is right on with Mike, but you'll have to wait...he's super backed up now.

If you truely want a 45 cal in a performer, there is a gunsmith Mike Milli aka Dtech who excels and is a pioneer in off caliber AR-15's.
He will make you a WSSM necked up to .458 using rifle bullets instead of the .451-.452 pistol bullets of the Bushmaster.
Performance will be in excess of the 45-70. He also sells a .358 version to have less of a rainbow trajectory at longer ranges. Case capacity is performing to the 30-06 size case equivalent while still fitting in a AR-15 magazine. Olympic Arms did the initial research on the .458 version cartridge but never marketed it.
The 30 cal version is out performing the 30-06 and is just shy of the 300 Win Mag and makes the Black Out look like a BB gun.

His WSSM versions are available in .224,.243,.257,.264,.308, .338,.358 and .458 bores.

Mike is highly sought after and has a great following in the hunting AR community.

[jerdebson]

MarkCO is right on the 450B. It is very accurate and under 300 yards I would not be afraid of shooting anything in North America. The problem with the 450B is that most people don't realize that it will shoot any .451, .4515, .452 or .454 bullets pretty much just load them. Where the 450B shines IMO is that the .458 bullets can be swadged to .452 and safely used in the 450B. That gives the 450B more bullets to load for what ever your needs are.

We can load the .452 Hornady 230 gr FMJ bullets to over 2500 fps easily in a stock gun. You would not believe how much meat and bone that will go thru before it stops. Some of the adventuresome souls have modified their 450Bs in ways that can bump that to around 2700 fps. That bullet will just keep on going, and stay together. I am just a novice in the 450B arena but having hunted, shot and reloaded for 40 years I find there is a place in my safe for a "Thumper".

In no way am I against the other Big Bores, I would love to have a 458S but there is a limit to what I can afford to build, buy and feed. 1 - .556, 2 - 6.8x43, 1 - 450B, 1 - 6mmAR( so I am shut down for a while.)

[Armada]

Anybody having any luck finding 450 B anywhere?

[Dave]

Anybody having any luck finding 450 B anywhere?

Nope, and the .458S upper I ordered from RRA back in April is on indefinite backorder. Even Bushmaster's website doesn't have anything new on their .450 availability. It looks like manufacturers are just spitting out 5.56 stuff right now to get what they can on the remaining panic buying. Though Buds and even CTD are starting to sell BM and DPMS 5.56 rifles at 800 and under, so I am hoping production might start shifting back to the niche builds.