My 450 bushmaster pistol adventure

[Eddie Gunks]

So on the 4473 you marked "other"? Also when added to the permit what was provided for caliber?

When you transfer a lower on a 4473 IT IS ALWAYS LABELED “other”

ALWAYS.

 

[Marine Cpl]

Alright so I have been checking out some factory loads for the bushmaster and playing guessing game with velocity for a 12.5" barrel.

Looks like most loads are a 250 grain bullet going (advertised) 2,200fps, I'm going to guess that it's from a 16" barrel but have no way of knowing.. and I figure 25-50fps loss per inch.

So on the high side of 4" losing 200fps I'll be looking at a 250 grain pill going about 2,000fps which should give me about 2,220 FT LB of energy at the muzzle which isnt bad at all...

I figure I can get into hand loading and maybe even work up some loads to try and get closer to the 2,200fps with the shorter barrel and that will give me about 2,687 ft LB if energy which is even better. I can do small batches of handloads just for hunting and off the shelf stuff for fun at the range

Looks like other than extra penetration due to weight, you got yourself a .300 Blackout as far as tissue disruption goes with that velocity.

 

[Edwardteach72]

Few more goodies came in today, more on Thursday and Friday.

Gas tube (carbine length)
Gas Block .875 midweight
Modified Lancer magazine (10 rounds of 5.56 or 4 of .450bm)
New follower for better reliability with the .450



If everything goes to plan.... I will be ordering my barrel and bolt this Friday to complete my build..

 

[repete]

Well done! I don't know how to approach doing this in Monroe County.

It's been awhile but I just found this thread. Monroe Co. shouldn't be a problem with" Multi." They've been using that for TC Contenders for awhile now just ask or tell.

 

[Edwardteach72]

Well dang another package.. my A2 style flash hider... another package tomorrow. And the best part.. all that is left is bolt and barrel which are being ordered Friday morning..

 

[Jem45472]

Well dang another package.. my A2 style flash hider... another package tomorrow. And the best part.. all that is left is bolt and barrel which are being ordered Friday morning..

View attachment 53268

Just in time, I hear .450 is going on the ban list.

 

[Edwardteach72]

Just in time, I hear .450 is going on the ban list.

No I think you are thinking of the .458socom that was designed for the battlefield and murder, while the 450bushmaster is just a humble hunting cartridge

 

[Edwardteach72]

Alright well only thing left to get is my barrel and the bolt. 7am tomorrow morning they will be ordered from Tromix who is super on the ball and if the last 2 packages from them is any indication I should have them by Monday.

Today my dust cover and forward assist came in and they are now installed



And looking at the port cover spring, you can see just how much the XL ejection port is opened up over a standard AR 15

 

[Edwardteach72]

Picked up some ammo today so I have it on hand to function test when my barrel comes in



7.62x39 on the left, .450bm middle, 5.56 right

 

[redtail]

Dont forget the dies.

 

[Edwardteach72]

Dont forget the dies.

Yea I'm going to have to get even just a basic reloading set up. Especially since I'm going to try and find if I can put together a good accurate safe load to send a 250g pill at 2,000 or 2,1000fps

 

[BMF JK]

That’s a nice looking pistol ya got there ! Can’t wait to see pics of the deer ya take with that bad boy .

 

[Edwardteach72]

That’s a nice looking pistol ya got there ! Can’t wait to see pics of the deer ya take with that bad boy .

Thanks Super pumped about testing it out tomorrow. And man tagging a deer with it this year would be wonderful hahhaa

 

[BDinPutnam]

Please run this on a frying pan or two so we can finally settle that issue.

What? It's a .45... technically...

 

[Marine Cpl]

Please run this on a frying pan or two so we can finally settle that issue.

What? It's a .45... technically...

It’s actually a .45 sized 300 Blackout.

 

[Edwardteach72]

It’s actually a .45 sized 300 Blackout.

Sure will sure

 

[Marine Cpl]

Sure will sue

?

 

[Edwardteach72]

Sure* not sue

 

[Marine Cpl]

I don’t understand what that means.Sure will sure. Isn’t that a 45 caliber projectile going at 300 blackout velocities?

 

[BDinPutnam]

I'm sorry I said anything.

 

[Edwardteach72]

I don’t understand what that means.Sure will sure. Isn’t that a 45 caliber projectile going at 300 blackout velocities?

Will as in your old name. Yup you are correct.

They go the same speed so they are the same thing

 

[Marine Cpl]

They go the same speed so they are the same thing

Not exactly. The extra weight of the bushmaster has more penetration for tougher and beefier animals but besides that, they behave the same as far as tissue dispersion goes due to the similar velocity.

 

[Edwardteach72]

Not exactly. The extra weight of the bushmaster has more penetration for tougher and beefier animals but besides that, they behave the same as far as tissue dispersion goes due to the similar velocity.

And close to 1,000ftlb of energy.

After some more research looks like the 450bm is in line with traditional 45/70 loads

 

[Marine Cpl]

And close to 1,000ftlb of energy.

After some more research looks like the 450bm is in line with traditional 45/70 loads

I think the Bushmaster is better. The 45/70 shoots at pistol velocities while the Bushmaster does so at rifle velocities. Bigger hole due to rifle sized stretch cavity.

I think it’s even better then the other competitors too.

 

[Edwardteach72]

I think the Bushmaster is better. The 45/70 shoots at pistol velocities while the Bushmaster does so at rifle velocities. Bigger hole due to rifle sized stretch cavity.

I think it’s even better then the other competitors too.

View attachment 53646

Modern 45/70 can get over 3,000ftlbs

 

[Edwardteach72]

But the 45/70 requires barrel lenght while the .450bm does not

 

[Edwardteach72]

Velocity Testing | Thompson Center Barrels | Match Grade Machine

 

[Edwardteach72]

And a 250g pill at 2,077ftps (13" barrel) gives 2,631ft/lb of energy

But hornady makes a 325g 45/70 doing 2,050fps which comes to 3,032ft/lbs of energy

 

[Marine Cpl]

I wouldn’t put so much stock in energy numbers for killing . The heavier grain bullets have more energy but they go below 2000 FPS so the stretch cavity is smaller and doesn’t become permanent. They pinhole like pistol bullets do and the wound track is the size of the bullet itself.

With something like the Bushmaster going at well over 2000 FPS , the stretch cavity stretches beyond elasticity and the hole is actually bigger than the slower moving bigger grain loads.

 

[BMF JK]

View attachment 53665

how’s it runnin !?