I headspaced my new 6br Criterion 1-7.5" twist barrel on to an Origin action a couple of weeks ago. I took it out last week with a load I pulled off of quick load. I changed the defaults to get close bullet length, case capacity, brass length. First outing I started with 15 rounds at 100 yards sighting in and a little break in. It knotted them up easily. I knew the speed would not be what q.l. said from experience with my buddy's 6br ( very similar to mine ). I ran a dope chart of 2850 fps and went with that. I screwed in the 600 yard dope and started banging a 45% impsc, easily again. So I moved over to a 36" gong and shot a 6 shot group that was 5". I then took it to 800 yards. There at 800 was a smaller impsc than the one at 600. I sent 8 rounds down there 4 on in a nice horizontal line on the 8" wide target, the 4 misses were just left and right of target. (Wind). At this time I realize I'm run 2/10th of a mil low on elevation. I now go to the 1000 yard 36" gong. Sent a couple of rounds down there. The 105 Nosler RDF bullet was leaving fairly light marks on the 1" thick steel. I had to come off my 12x Super Sniper scope and go to the Vortex spotting scope to see them. I went back to the rifle and studied the wind a little made a 2/10 mil elevation adjustment and a windage adjustment then shot a 5 group. The group was a little big for my liking but they were fairly together well enough for starters for me with a 6br, seeing how I'm used to running a 6mm Competition Match with a 115 DTAC at 3150. 60 rounds down the tube at this point.
So yesterday I take it to the club I belong to and put a target up at 300 yards and 45% impsc to hear and see some visual impacts (little fuzzy feeling). I shot 40 rounds, some on steel, some in a shoot n see. The 91-100 rounds down the barrel ended up like this, straight down the middle. The group was 9 that had the group at 1.5" the tenth shot at 6 o'clock opened it up to 2". This rifle is for PRS type shooting and I may take it to September's 600 yard f class shoot. All this is with virgin Lapua brass, H4895, CCI 450, Nosler RDF 105's. Before anyone craps on the bullet, I have a stash of Hornaday Amax 105's, and will try the Berger 105 Hybrid if I think I need too.
Don Dunlap
So yesterday I take it to the club I belong to and put a target up at 300 yards and 45% impsc to hear and see some visual impacts (little fuzzy feeling). I shot 40 rounds, some on steel, some in a shoot n see. The 91-100 rounds down the barrel ended up like this, straight down the middle. The group was 9 that had the group at 1.5" the tenth shot at 6 o'clock opened it up to 2". This rifle is for PRS type shooting and I may take it to September's 600 yard f class shoot. All this is with virgin Lapua brass, H4895, CCI 450, Nosler RDF 105's. Before anyone craps on the bullet, I have a stash of Hornaday Amax 105's, and will try the Berger 105 Hybrid if I think I need too.
Don Dunlap
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