Lead melter
02-28-2008, 03:32 PM
Here are my findings of the second round attempting to find just how fast a pure lead boolit can be driven with some degree of dependable accuracy.
What follows is an accuracy result with chrono figures using IMR-3031 powder in 22, 23, 24 grain charges as these were the most promising of the 5 loads tested last week. This report tested at 100 yards. Groups are 5 rounds.
Also accuracy and chrono figures for 24, 25, 26, 27, 28 grains Win 748. This result tested at 50 yards.
Testing parameters can be found on my post "Testing tomorrow" as of 2/20/08.
22 grains 3031
4.084"
velocity ave.-1321 fps
23 grains 3031
group size exceeded area of target, but 4 rounds in 3.192"
velocity ave.-1476 fps
24 grains 3031
group size exceeded area of target, but 4 rounds in 4.387"
In my opinion the 22 grain charge is probably maximum velocity in this particular rifle using that lube, that powder, that primer, that boolit, the gas check, etc. Your results may vary.
24 grains 748
group 1-3.647"
group 2-4.567", with 4 in 2.447"
group 1 velocity ave.-1414 fps [readings from 1245 fps to 1673 fps]
group 2 velocity ave.-1447 fps [readings from 1298 fps to 1557 fps]
25 grains 748
group 1-3.764", with 4 in 1.387"
group 2-3.532"
group 1 velocity ave.-1236 fps [no extreme spreads]
group 2 velocity ave.-1339 fps [readings from 967 fps to 1553 fps]
26 grains 748
group 1-2.494"
group 2-7.505"
group 1 velocity ave.-1447 fps [readings from 1371 fps to 1647 fps]
group 2 velocity ave.-1493 fps [readings from 1271 fps to 1675 fps]
27 grains 748
group 1-4.612"
group 2-2.742"
group 1 velocity ave.-1513 fps [readings from 1073 fps to 1769 fps]
group 2 velocity ave.-1443 fps [readings from 1217 fps to 1522 fps]
28 grains 748
group 1-6.442"
group 2-3.722"
group 1 velocity ave.-1694 fps [no extreme spreads]
group 2 velocity ave.-1658 fps [no extreme spreads]
My opnion is that the extreme velocity variances in the reduced loads of 748 affect accuracy and consistency too much to be an effective powder for slower velocities. As velocities increased, extreme spreads dropped, but accuracy of the soft boolit would not maintain. Based on this principle, no further testing of 748 will be done on this topic. Gas blow-by was also erratic and voluminous. As you can see, some of these loads varied enough to be downright scary.
Next scheduled is H-4198.
What follows is an accuracy result with chrono figures using IMR-3031 powder in 22, 23, 24 grain charges as these were the most promising of the 5 loads tested last week. This report tested at 100 yards. Groups are 5 rounds.
Also accuracy and chrono figures for 24, 25, 26, 27, 28 grains Win 748. This result tested at 50 yards.
Testing parameters can be found on my post "Testing tomorrow" as of 2/20/08.
22 grains 3031
4.084"
velocity ave.-1321 fps
23 grains 3031
group size exceeded area of target, but 4 rounds in 3.192"
velocity ave.-1476 fps
24 grains 3031
group size exceeded area of target, but 4 rounds in 4.387"
In my opinion the 22 grain charge is probably maximum velocity in this particular rifle using that lube, that powder, that primer, that boolit, the gas check, etc. Your results may vary.
24 grains 748
group 1-3.647"
group 2-4.567", with 4 in 2.447"
group 1 velocity ave.-1414 fps [readings from 1245 fps to 1673 fps]
group 2 velocity ave.-1447 fps [readings from 1298 fps to 1557 fps]
25 grains 748
group 1-3.764", with 4 in 1.387"
group 2-3.532"
group 1 velocity ave.-1236 fps [no extreme spreads]
group 2 velocity ave.-1339 fps [readings from 967 fps to 1553 fps]
26 grains 748
group 1-2.494"
group 2-7.505"
group 1 velocity ave.-1447 fps [readings from 1371 fps to 1647 fps]
group 2 velocity ave.-1493 fps [readings from 1271 fps to 1675 fps]
27 grains 748
group 1-4.612"
group 2-2.742"
group 1 velocity ave.-1513 fps [readings from 1073 fps to 1769 fps]
group 2 velocity ave.-1443 fps [readings from 1217 fps to 1522 fps]
28 grains 748
group 1-6.442"
group 2-3.722"
group 1 velocity ave.-1694 fps [no extreme spreads]
group 2 velocity ave.-1658 fps [no extreme spreads]
My opnion is that the extreme velocity variances in the reduced loads of 748 affect accuracy and consistency too much to be an effective powder for slower velocities. As velocities increased, extreme spreads dropped, but accuracy of the soft boolit would not maintain. Based on this principle, no further testing of 748 will be done on this topic. Gas blow-by was also erratic and voluminous. As you can see, some of these loads varied enough to be downright scary.
Next scheduled is H-4198.