A minor accuracy and velocity update; since it may be all I can manage before the Elk hunt.
I got another chance to shoot some of the 275 grain bullets across a chronograph last Saturday. I was quite surprised at the result. The velocities are as much as 150 fps faster than I had estimated.
Whether it's due to decreased bore friction, from the zinc in the brass; or due to using slightly under-sized projectiles (by 0.0005"); I don't know. But, they are running faster than expected.
Back in post 17
, I had estimated 47.5 grains H4198 to be pushing these bullets at 2,225 fps. However, Saturday's testing showed that load to be averaging 2,363 fps.
From there, the velocities consistently increased.
I was having a bad day and couldn't really hold things together. So, I only managed to print a 4-shot group of about 3" @ 80 yards (I didn't bother measuring).
However, my father was 'on his game', and managed to hold on to a 1-3/4" 4-shot group, at the same distance.
So, these bullets appear to be perfectly capable of "hunting accuracy" at a minimum; and further load development may even tighten things up.
I say "may" because I wasn't able to finish testing everything I had loaded. I had barely gotten started with the .40 S&W bullets.
My experimental "One Ounce Suppository" cast bullet loads managed to shift the scope in its rings, and I didn't have the tools to fix it. So, the .444 had to be put away for the day, without finishing what I had started with either
set of tests.
--The one ounce suppository being a 428 gr bore-rider bullet, whose load increments got it to 1,855 fps in a 6.3 lb rifle, before recoil took revenge on the scope. (I can't say that the shooter was really enjoying the recoil, either, though....)
If all else fails before then... I may just do some more testing during
the Elk hunt.