I was testing some loads in my Weatherby Vanguard 270 Winchester in preparation for deer season. While I'm not going to be shooting it, my younger cousin and sister will be taking it during rifle season. I've been having quite a few issues with the gun lately, though, and today was no different. Here's what's happening:
130 grain Hornady SST - 3.405" OAL
Remington case
53.0 grains IMR 4451
Federal Large Rifle primer
3,020 fps average, 6 fps s.d.
130 grain Hornady SST - 3.405" OAL
Remington case
55.0 grains IMR 4451
Federal Large Rifle primer
3,141 fps average, 18 fps s.d.
As you can see, I'm getting two distinct groups quite some distance apart. However, the individual groups are somewhat tight. In the top picture, the three-shot group was .835", while the three-shot group on the bottom was .740", both at 100 yards. On their own, they would certainly be groups to be proud of, but with the other two bullets grouping elsewhere, I can't be comfortable with these loads yet. There was no real pattern to how the bullets hit, either, and I let the barrel cool between shots, so I don't think barrel heating was the issue.
My question is, what could be causing this? I'm wondering whether I'm not holding the rifle consistently enough between shots. Additionally, I was using a Lead Sled, which I've heard isn't conducive to the best shooting. The way I see it, I have two options: make some loads I've confirmed are accurate and see what happens, or test these loads for accuracy again using my pistol rest and a sandbag to rest off of.