Tried some 4064 in and OCW test and the promising results were at speeds we're not supposed to see with a 22-inch barrel.
FA 63 Match cases, reloaded 1x before
WLR primers
Seated 2.82 or so OAL
New ordinary match barrel from Springfield Armory
Temp 80 F, humidity probably 30-40.
45.0 (last of the 3 sighters, started at 43.4 and didn't get speeds)
2893.1
Shots were fired round-robin style.
45.3--2898.6, first two shots touching, 3rd an inch away at 11:30
45.6--2890.7, first two shots touching, 3rd 1-3/8 inch away at 10:00
46.0--2912.6, first two shots same hole, 3rd 1-3/8-inch away at 11:30
46.3--2926.9, first shot in the same spot as the first two in the prior three loads' groups, 2nd an inch away at 10:30, 3rd another half-inch above the 2nd
46.6--2959.8, first two shots almost touching, a half-inch left of the rest of the earlier groups' first shots, 3rd shot 7/8-inch away at 11:00.
With the earlier barrel, the rifle tended to shift POA up about 1 MOA after firing 8-12 shots in a string. Perhaps this is also at play.
But since I expected safe velocities to top out at about 2880 or so from a 22-inch, I'm going back for a re-test with 45.6 as the top charge. Faint prints of the line on the bolt where the extractor sits were visible starting at 45.6, and ejector wipe started showing up at 46, so I'm not going to chase the accuracy even at 45.6. I'm not even sure about accepting 45.3 unless I get QuickLoad and the pressure estimate if good for these cases (water capacity 55 grains).
Some of these groups are at 1 MOA with the last shot included, with horizontals between 1/2 and 3/4 (only 1 had horizontal of 1.1 inch). That may be the limit of the barrel, but if it has a POI shift that's predictable in both onset and distance, I can keep shots at 3/4 MOA or significantly less.
I hope.
FA 63 Match cases, reloaded 1x before
WLR primers
Seated 2.82 or so OAL
New ordinary match barrel from Springfield Armory
Temp 80 F, humidity probably 30-40.
45.0 (last of the 3 sighters, started at 43.4 and didn't get speeds)
2893.1
Shots were fired round-robin style.
45.3--2898.6, first two shots touching, 3rd an inch away at 11:30
45.6--2890.7, first two shots touching, 3rd 1-3/8 inch away at 10:00
46.0--2912.6, first two shots same hole, 3rd 1-3/8-inch away at 11:30
46.3--2926.9, first shot in the same spot as the first two in the prior three loads' groups, 2nd an inch away at 10:30, 3rd another half-inch above the 2nd
46.6--2959.8, first two shots almost touching, a half-inch left of the rest of the earlier groups' first shots, 3rd shot 7/8-inch away at 11:00.
With the earlier barrel, the rifle tended to shift POA up about 1 MOA after firing 8-12 shots in a string. Perhaps this is also at play.
But since I expected safe velocities to top out at about 2880 or so from a 22-inch, I'm going back for a re-test with 45.6 as the top charge. Faint prints of the line on the bolt where the extractor sits were visible starting at 45.6, and ejector wipe started showing up at 46, so I'm not going to chase the accuracy even at 45.6. I'm not even sure about accepting 45.3 unless I get QuickLoad and the pressure estimate if good for these cases (water capacity 55 grains).
Some of these groups are at 1 MOA with the last shot included, with horizontals between 1/2 and 3/4 (only 1 had horizontal of 1.1 inch). That may be the limit of the barrel, but if it has a POI shift that's predictable in both onset and distance, I can keep shots at 3/4 MOA or significantly less.
I hope.
