I am getting the feeling that this rifle likes burn rates on the slower side.
Tony
I agree. I went through this same drill with the 280 years ago,when RL22 was new on the market.
I tried IMR4350,which gave great accuracy and low velocties(pushing harder gave pressure signs);then to IMR4831,which gave somewhat higher velocities but accuracy soured.
I noticed that some sources used MRP with good results, but it was not commonly available, so tried RL22,which was similar but not the same.
RL22 proved to be the ticket, giving vels in the 3100 fps range and excellent accuracy(bug hole type)with 140 Partitions and BBC's.
Found pretty much the same in other 280's as well.
A pal recently wrung out a KS Mountain rifle in 280...I told him to try R22;he insisted on R19.....which seemed OK until he burned R22,which was visibly better.
Can't guarantee the same results from all 280's,but if I bought a 280 tomorrow R22 would be first up,and I doubt I'll have to look much further.
I'd burn it with a Fed215 mag primer as well.
For some reason R22 and Fed 215's are a safe place to start in the 280 and 7RM.The combo is not chump change in the 270 Win either.
