Large SD on H322 loads?

[Copperhead]

Shooting T3 in 204.
Loading 32 VMax ,Hornady Brass, H322 25.8, 26 ,26.2grains, , CCI 450 primers.
Using RCBS charge master, Lee sizing die, Forster seating die.
Caldwell chrony
I m getting decent groups .75 but the SD is 75-80 with a range of 3770 to 3900 .
Any input as to experience or ideas as to why welcome.

[Rick in Oregon]

Any input as to experience or ideas as to why welcome.

From past experience, I believe that H322 is not ideally suited to the 204, being a bit on the fast side for consistent performance. I use it with good success in my 17M4, also in my 221FB on occasion. The smaller case is better suited to the burn rate of H322.

My best powders in the 204 have been RL-10X, Benchmark and H4895 with the 39/40gr bullets. I know powder is hard to come by right now, but try another more suitable powder in your rifle if possible. It appears you've got a decent barrel on her, you just need a better powder with the proper burn rate (slower) for the 204 case.

Let us know how it all shakes out when you've had a chance to try something different.