77 hpbt loading suggestion

[round]

Iv'e had better luck running 77's in a 1:7

 

[Fern]

Define shotgun pattern for us. Please. What power scope and any other details about the pattern and shooting set up. Suppressor? Check all the fasteners. Might be worth running the bore scope in there and trying a spare scope. Be open to the idea it just might not shoot small groups. Have you shot the rifle too? Is the barrel crown ok

Lots of good info appreciate it all
Scopebis a Leupold x18
No suppressor just the brake that came on it
Shots two shots ok then starts flinging 2” flyers in random directions.
I have not shot it yet buddy just wanted to see if I could help him come up with a load that works
He shot factory Winchester 55gvmax rounds and not sure what else
He hopes to also use it on on dogs and on ked up some sierra 60g varminter hp but he bought 500 of these 77s on recommendation of another shopper who spoke very highly of them paired with 7 /1/2 primers.

 

[CF Junkie]

A 1/8 twist should stabilize a 77gr HPBT without any problem.
But rifle barrels always seem to have preferences and his may not prefer heavier bullets.

I had a 1:9 twist .223 (I measured the twist at 1:8.75) that stabilized 77 SMKs and they shot great, better than all the other bullet weights that I tried other than 73 gr Bergers.

Could be your friend is letting the recoil move him around a bit and he is not in the same position after a couple of shots. Funny how little things matter so much, and if you aren't really self-observant, you don't even notice you are changing your set up and moving your Point of Aim.

 

[coldboreshot]

You may want to explore other recipes other than just powder choice. Maybe another brass and primer. A sleeve of primers, an lb. of powder and a bag of brass might be worth the satisfaction. Hell, for me, half the enjoyment is the experimentation.