Down to Two Weeks till the Missouri Deer Season, and my hunting preparation has been close to non-existent so far.

I got everything together this evening, and got Thunder Beast put together. I cleaned the scope base threads, and mounted my Bullberry 6 screw scope base. I got the Bullberry Hanger bar installed and adjusted, and mounted the Bullberry Forend. I then mounted a Burris 2-7 Ballistic Plex scope in a pair of Burris Zee Rings. I have a Bubble Level on the scope tube.

Thunder Beast is a 7.62 X 54R (308 Bore) Encore. More correctly it would be a 7.62X53R with the .308 bore. The barrel is just shy of 16" not counting the 4 Gill Muzzle Break. She has a full 1" barrel, the same as my 260 Rem Bullberry barrel. Twist is 1 in 12 which should be optimum for 125 - 165 grain bullets.

I should have time Thursday and Friday to get it sighted in. I plan to get some ammo loaded Monday evening after I get off work. I plan to start off with 125 grain Sierra Pro Hunters in front of 50.0 grains of H4895. I am predicting this load to chronograph around 2600 fps. I will probably load a couple at 48.0 and 49.0 to begin my chronograph session with, just to be careful.

I need to find a few minutes between now and this time next week to check all the ladder stands, and the wife's tower stand.

I am normally trying to wear out my hunting handguns the two months before season. That did not happen this year.

Bob R

I like the sound of that load,,, Good Luck to you.

Charles

Good luck!

I have Round One of my test loads for Thunder Beast put together.
prvi-partisan commercial brass
CCI Bench Rest Large Rifle Primers
H4895 Powder
Nozler 125 grain Ballistic Tip bullets
OAL: 2.88

I loaded 5 rounds each with:
47.5 grains (JMS 02 Brass)
48.0 grains
48.5 grains
49.0 grains
49.5 grains
50.0 grains
50.5 grains

FYI: I had 5 rounds of military contract ammunition on hand. It is marked JMS 02. Speculation is that the JMS 02 ammunition is US DOD Contract ammunition of prvi-partizan manufacture. This military ammunition had a lead core .311 Boat-tail Ball Bullet weighing 171-171.5 grains, in front of a 46.0 grain powder charge of a fine grained stick powder closely resembling H4895. The primers had a Red Sealant but were not crimped in.
With 50.5 grains of H4895 in both the DOD Military Contract and commercial prvi-patrizan cases, the powder levels looked to be identical in both.

I should be able to get in a Range trip Thursday.

Bob R

Thursday was a Rain Out. I went to Carters and got a couple more boxes of bullets. I determined that My 50.5 grain load was not a maximum load. I loaded a few more rounds to test at 51.0, 51.5, and 52.0 grains.

Finally it was not raining on Friday Morning. Off to the range I went.

The 51.0 load broke 2800 fps. For what ever reason 51.5 only averaged 4 fps more velocity. The 52.0 load averaged just over 2850 fps.
I decided the 51.0 load at 2800 would work.
I fired 50 rounds during my testing. I loaded a few more rounds and went back to the Range late in the afternoon. I put a target up at 100 yards. I marked a heavy vertical line on the target, and put a 3" Orange Dot on this line. I put a Cross bar at 1.90 above the Dot Center. This would be my 200 yard zero. The first two shots were approximately 4 inches high, and on the line. I came down 8 clicks and fired two more rounds. I was now on the Cross Bar. Perfect 200 yard zero. Before leaving the Range I planted two shots on the 300 yard steel. Holding on the top edge of the steel plate which was 16" high ( Hold Over was 8.4 at 300 yards ) I fired two shots. Both looked to have impacted very close to the Red Dot on the steel targets center.
It looks like Thunder Beast is a shooter.
The four Gill Brake really works well. Recoil was Rifle Scope Mild. The Muzzle Blast was a different story however. It will blow items of the bench's on both sides of you.
Now all I need to complete the build is a case.

Bob R

Sounds like you are finally ready. Good luck on this.

SO WHAT LOAD DID YOU SETTLE ON?

Sounds like a great load. I have to admit, in your original post it sounded like you were looking to stop at 2600 FPS and I figured the '54R would do more. 2800 sounds really nice! I wonder what that bullets velocity will be at 300 yards? Just for giggles, there is also that Barnes 110 grainer you could play with, though it, being designed for the 300 Black Out, would be explosive at close range out of your pistol.

45MAN
Bullet: Nozler 125BT
Powder: H4895
Powder Charge: 51.0
Primers: CCI BR2
Case: Prvi-Partizan

JDK
Per the Hornady Ballistic Calculator
Muzzle: 2800 fps
100 Yards: 2557
200 Yards: 2327
300 yards: 2109

It slows down pretty fast.

Most of my hunting locations are limited on yardage. I do have a couple locations where 200 yards is possible.

I have 150BT and 165BT bullets on hand. I may take a look at a heavier bullet and see what the advantages are.

Bob R

That's still a very capable velocity at 300 with that bullet. looks like a fantastic all-around pistol and load! Keep us updated on you results.

Can't argue with those results. Sounds like you've got yourself a pretty potent performer.

Here is a picture of Thunder Beast in the field. I had no more than taken this picture when I spotted a large doe about 130 yards West of the tower stand. After milling around eating for about 10 minutes, she bedded down until about 4:20 PM.

Thunder Beast's first Range visit.

Close up of the Four Gill Muzzle Brake.

My target from the first 50 rounds of chronograph work. The range was only about 35 yards. The Velocity Spread was 2395 fps thru 2852 fps. That was the reason for all the vertical spread. A 450 fps velocity difference from Mild to near Maximum.

So far I have been very impressed with this build. Mike Russell "Legacy Gun Cases" should have my custom 26" case with shoulder strap delivered shortly. I will still need to scope the Bullberry 260 barrel. Probably a 3-12 Burris.

Bob R