Spun together a build which came about from multiple "Black Friday / Cyber Monday" sales on components.

I already had the lower so it was just an upper build.

Barrel/Bolt was from Tromix, I was amazed at the lightweight profile, when I first picked up the USPS box on the porch I thought "Did they forget to put the barrel in here".

Generic steel lopro gas block, black mid-length gas tube, NIB bolt carrier, cheap Chinese hand guard (steel barrel nut), Wilson combat muzzle brake (I hate unique threads I considered the Wilson my only brake option), and a F-1 firearms upper receiver.



Test fired the build yesterday with Hornady 250gr factory ammo at 100 yards, below is a 4 shot group off double bags.



I am deciding to not spend 30.00 bucks a box to shoot factory ammo albeit with performance like shown above I really wouldn't have a problem doing so....

I am handloading a muzzle loader bullet (Monoflex - GMX) which is also 250 grains however in this photo you'll see that the muzzle loader bullet is longer than the factory FTX projectile.



I tested a variety of Lil'Gun loads and decided that 34.8 grains at 2251 fps was the best in terms of velocity and accuracy. The group size opened up slightly from the factory loads - I EMPHASIZE slightly



Recoil on this lightweight upper build is stout, a quick and direct punch back, however I shot 50 rounds without any discomfort.

The Sightmark PhotonXT didn't skip a beat ! I had tried it previously on a 458 Socom build and the recoil would shutoff the scope - no problems with 450 Bushmaster.

I hope to get this gun afield in January, I'll post up pictures of bullet performance on hogs.

I am overall IMPRESSED by the caliber so far!

Looks like fun! No suppressor?

Nice shooting!

The Bowers is on sale at the moment - 699 plus stamp and incidentals but I kind of like the short compact AND lightweight feel as it sits .

I've seen videos of 458 Socom with the Bowers and it just looks like a long tube of metal , not sure that it tames the recoil as much as on smaller bore calibers...

That's good shootin!

Never seen that upper before. Looks nice.
Interesting that the 458 had more recoil than the 450. I figured they would be about the same.
The Bowers cans are heavy and they do a pretty good job of suppressing and taming the recoil of the big bores. I shot a buddy's 50 Beo once without hearing protection. VERY loud and lots of recoil. Made me not want one anymore. Then I shot it with the Bowers can on a couple months later. It was now hearing safe and definitely tamed the recoil. I wanted one again. I have a 458 and a Bowers 50 can. Haven't taken it to the range yet.

The only knock I have on the upper receiver is that it requires the use of a 70.00 reaction rod to install the barrel and muzzle brake. This is to avoid fracturing or deforming the upper receiver when applying the necessary torque. It's a necessity in my eyes as I usually use vice blocks and I am one of Murphy's best friends.

Bullet: Hornady Monoflex .452 (sold as a .50 muzzleloader w/ Sabot)

I settled on 34.8 grains of Lil'Gun and got the kinks worked out of the extractor and magazine so I headed to the lease on Saturday and put the 450b through its paces.

No hiccups and with the Sightmark PhotonXT there was very little rise and drop from 30 - 150 yards which should be considered the gun's "effective range".

Overall I am happy with the weight/recoil/performance of the 450b, now to find the best hunting bullet and go from there...

I didn't know that big bore was capable of such consistent shooting. That's super cool! Congrats!

And this is with a fixed mag digital scope, you'd get really small groups with a real optic.

The 3x6 inch bulleyes looks like a tiny dot on the digital scope beyond 150 yards so I have to really concentrate on holding still and pulling through the trigger consistently.

Just shows some fine work on the shooter's part!

You will be happy with the Bushmaster's performance on hogs !