450Bushmaster.net

I got it together, and broke in the barrel per MGM's instructions. It's a very handy little piece. Definately will be threading it and screwing on a brake. As can be expected, it's quite ferocious with synthetic hardware and a short barrel. Some handload testing to follow soon.

Loaded up a couple loads today. Just conserving components with 2 shot groups to get a feel for what it likes. Using the 250gr Hdy mono's and LilGun to start. I used 30-34gr in 1gr increments. The 34gr load really shined, but the primers weren't happy and the action just started to get sticky, so a little too much. These are CCI 400's. I also have WSR I will load next. Not a lot of load info with these mono's. Got a LOT of bullets and powder to work up loads, so the fun is just beginning.

The 450bm is really handicapped with the AR mag length restriction of factory rounds. Here is a pic of a factory shell on the right, and the MGM chamber length. So plenty of room to work with.

Here is a 300gr Pittman Accumax bullet. They are made for high performance smokeless muzzleloader, but work in any 452 cartridge if you have room. They add a lot of range with their awesome bc. I shoot these to 400yds in my mz. Every single deer has been drt. They have an aluminum tip and med jacket thickness for great expansion.

been eyeing those Pittmans or Parker's Black Max for my 45 Raptor.

you shoot any of those Pittmans yet?

Al in Mi wrote:been eyeing those Pittmans or Parker's Black Max for my 45 Raptor.

you shoot any of those Pittmans yet?

Not thru the 450bm yet.

I did in a 460sw Encore barrel. I never got that one shooting good with full power loads tho. Using 454 Casull brass, it was no problem getting good accuracy, but I didnt get a 460 for that. I sent that barrel away, and went with the 450 per MGM's recommendation of it.

Have had enough fun and happy so far, I am dropping off the new tube for threading and a brake. My buddy is a basement gunsmith on the side, and does excellent work at very reasonable cost. I have had him do 4 MGM's, 4 or 5 factory TC's, 2 PacNor's, and a few others, as well as friends guns. ALL have been flawless!

We did a lot of R&D and several designs on the brake on my 460sw barrel that didnt turn out. We came to the conclusion that the fast burning pistol powder was not reaching the brake in a 24" barrel to work. The brake on my 18" AR 450bm worked excellent tho. Not much length difference, but apparently enough.

Rifle cartridges and slow burning powder get the most out of a brake. My 300wm was an angel after the work.

Here is one for the 450bm. We added the 4th hole to try, and it made a noticeable difference. The spacing was off, but we had tried so many ways, it was R&D as said.


This is the most common style he makes. It works great on most applications.



This an an integral brake MGM is using on the 450bm.

I've built and tested a lot of brakes over the years too and the the tank style like Ross Schuler has is hard to beat for $37ish to your door.

Here I went to pick up an MGM and they are out of stock. Keep us posted on yours.

B.

kottke_35 wrote:Here I went to pick up an MGM and they are out of stock. Keep us posted on yours.

B.

Watch MGM's inventory list, or check Haus of Arms. They stock premade ones from MGM, which is how I got this one.