I've got a questions for you kings of reloading. I took my CZ 527 FS out today, to test my Nosler 50 gr. Ballistic Tips loaded with IMR 4198. I worked my way up with single shots to check for pressure, and when I hit 20.7 grains (my first group), I was impressed.
I should also tell you guys about how I'm a bit on the weird side (apparently). I always shoot 4 shot groups. I then cancel out the farthest shot, and call it operator error, wind, flinch, whatever. That way I'm always left with a three shot group.
So, I went round robin. The three groups of particular interest were shot with 20.7, 20.9, and 21.1 grains. So I fired one round of each charge (allowing two minutes between shots, as I've always done), and started on the next round. With the 20.7 grain charge, I landed my second shot 1/4" away (to the left) from the first. I was happy with that. The 20.9 grain charge ended up about 3/8" away from the first, and the 21.1 grain charge ended up nearly an inch away from the first. Fine.
On to the third round. My 20.7 grain charge landed the third shot 1 1/2" away (lower) from the first and second. I kind of assumed it was my fault, but didn't think it should have been. The other two ended up in pretty much the same way.
The fourth round put my 20.7 grain charge within a 1/4" (to the right) of the previous shot. The 20.9 and 21.1 charges did the same thing, except they ended up about 1" to the right of the previous shot.
It was -9 degrees Celcius, only a very light breeze. Nothing changed (that I'm aware of) between the second and third rounds to make them drop 1 1/2" lower. I went on to shoot a coyote at about 280 yards with factory ammo (which it was sighted in for) later on towards evening, and the bullet ended up right where it should have, so it can't be the scope. Do any of you folks have any ideas?
I should also tell you guys about how I'm a bit on the weird side (apparently). I always shoot 4 shot groups. I then cancel out the farthest shot, and call it operator error, wind, flinch, whatever. That way I'm always left with a three shot group.
So, I went round robin. The three groups of particular interest were shot with 20.7, 20.9, and 21.1 grains. So I fired one round of each charge (allowing two minutes between shots, as I've always done), and started on the next round. With the 20.7 grain charge, I landed my second shot 1/4" away (to the left) from the first. I was happy with that. The 20.9 grain charge ended up about 3/8" away from the first, and the 21.1 grain charge ended up nearly an inch away from the first. Fine.
On to the third round. My 20.7 grain charge landed the third shot 1 1/2" away (lower) from the first and second. I kind of assumed it was my fault, but didn't think it should have been. The other two ended up in pretty much the same way.
The fourth round put my 20.7 grain charge within a 1/4" (to the right) of the previous shot. The 20.9 and 21.1 charges did the same thing, except they ended up about 1" to the right of the previous shot.
It was -9 degrees Celcius, only a very light breeze. Nothing changed (that I'm aware of) between the second and third rounds to make them drop 1 1/2" lower. I went on to shoot a coyote at about 280 yards with factory ammo (which it was sighted in for) later on towards evening, and the bullet ended up right where it should have, so it can't be the scope. Do any of you folks have any ideas?