Shrinkmd
Member
I made up some different strength batches of .357 Magnum with the following:
New Starline .357 brass
Montana Gold 125 gr JHP
Federal SP primers
Alliant 2400 (recent manufacture)
These were shot from a 627 PC 5" V-comp (with the comp installed, but it is after the barrel ends, so in theory isn't affecting it like a port in the barrel, right?) It was warm, about 85 degrees or so.
16 gr 2400
High: 1324
Low: 1204
E.S.: 120
Ave.: 1249.3
S.D.: 36.7
95%: 29.2
16.5 gr 2400
High: 1285
Low: 1197
E.S.: 88
Ave.: 1255.1
S.D.: 26.9
95%: 21.4
17 gr 2400
High: 1309
Low: 1209
E.S.: 100
Ave.: 1272.8
S.D.: 32.5
95%: 25.8
So the velocity isn't really going up much despite 0.5 gr increments in powder charge. 1 gr of 2400 only adds 20 fps???
Granted, these are only 10 shot samples, so I will retry this another day at the range when I have more time. Do these results make sense? Lyman says you can go to 17.7 gr 2400, and Alliant's GDHP data lists max at 17.5.
Given that they aren't going any faster, should I try working up any more or call it a day? Lyman 49th says these should be going 1478 with the 17.7 load out of a 4" universal receiver. Are the Montana Gold bullets too hard, so they are slowing down in the bore? I know you're not supposed to use magnum primers with the 2400, but the data from Lyman says they use CCI 550's with all the loads.
Of course, now that I look more carefully, the Alliant data lists 1409 out of a 10" barrel, wheras Lyman says 1478 out of the 4" universal receiver. I'm even more confused. By Alliant's data, my results don't look too bad, considering I'm missing 5" of barrel as well as having a cylinder gap.
So what kind of chrono results are people getting from similar loads?
New Starline .357 brass
Montana Gold 125 gr JHP
Federal SP primers
Alliant 2400 (recent manufacture)
These were shot from a 627 PC 5" V-comp (with the comp installed, but it is after the barrel ends, so in theory isn't affecting it like a port in the barrel, right?) It was warm, about 85 degrees or so.
16 gr 2400
High: 1324
Low: 1204
E.S.: 120
Ave.: 1249.3
S.D.: 36.7
95%: 29.2
16.5 gr 2400
High: 1285
Low: 1197
E.S.: 88
Ave.: 1255.1
S.D.: 26.9
95%: 21.4
17 gr 2400
High: 1309
Low: 1209
E.S.: 100
Ave.: 1272.8
S.D.: 32.5
95%: 25.8
So the velocity isn't really going up much despite 0.5 gr increments in powder charge. 1 gr of 2400 only adds 20 fps???
Granted, these are only 10 shot samples, so I will retry this another day at the range when I have more time. Do these results make sense? Lyman says you can go to 17.7 gr 2400, and Alliant's GDHP data lists max at 17.5.
Given that they aren't going any faster, should I try working up any more or call it a day? Lyman 49th says these should be going 1478 with the 17.7 load out of a 4" universal receiver. Are the Montana Gold bullets too hard, so they are slowing down in the bore? I know you're not supposed to use magnum primers with the 2400, but the data from Lyman says they use CCI 550's with all the loads.
Of course, now that I look more carefully, the Alliant data lists 1409 out of a 10" barrel, wheras Lyman says 1478 out of the 4" universal receiver. I'm even more confused. By Alliant's data, my results don't look too bad, considering I'm missing 5" of barrel as well as having a cylinder gap.
So what kind of chrono results are people getting from similar loads?
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