I've read several old threads but no one really confirmed it.....what is the official BC for the 123 AMAX g1/g7? I've seen some guys saying the g1 listed is too high? I need some reliable numbers for 800 to 1000 yards
123 amax BC
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Originally posted by cst View PostI've read several old threads but no one really confirmed it.....what is the official BC for the 123 AMAX g1/g7? I've seen some guys saying the g1 listed is too high? I need some reliable numbers for 800 to 1000 yards
I've gotten my best results using a G7 of .253, though.
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Originally posted by Kendoist4162 View PostHornady has the G1 BC listed as .510 on their site but no G7 number. There is a VERY good discussion thread on the G1 vs. G7 "thing" on Snipers Hide. Dunno if links are allowed to other places like SH, but it is easy to find. Edited - listen to the man above too. ;-)
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If anyone has the Applied Ballistics 2nd Edition, he might have done the BC analysis on it. Those are pretty authoritative. His analysis on the 123gr Sierra Match King showed that it was actually much higher than Sierra stated, even with their speed range variation. The 123gr SMK ended up being .522, not the listed .510 for G1. G7 was higher too, I think .260.
Someone on the forum should have the books and be able to look it up. He put out some recent ones with 400 different projectiles tested with live fire, not theoretical drag modeling and shape analysis only.NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com
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Here are Litz' numbers for the 123 SST, which I believe is the same (or at least very close) to the AMAX:
G1
overall .462
below 1500 .406
2000-1500 .432
2500-2000 .467
3000-2500 .491
Above 300 .526
G7
overall .236
below 1500 .228
2000-1500 .229
2500-2000 .235
3000-2500 .244
above 3000 .249
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Originally posted by cst View PostSo if Litz is correct with the G7 on the SSTs and I use .244 as my BC....its subsonic by 980yards...SUKS.
When I have used the stated BC on the 123gr AMAX, I was shooting out to 1200yds, and that's with the actual barometric pressure, temperature, and altitude entered into my ballistics program. I was at 4400ft elevation. One thing about tighter rifling is that it spins the pill so much that they stay stable through transonic, so you don't get erratic trajectory after the maximum ordinate like you do with loose twists.
Even still, I'm supersonic out to 1318yds in those conditions.NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com
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Originally posted by LRRPF52 View PostThe 123gr SST is not the same bullet as the 123gr AMAX. The ogives are different, and the cannelure is not present on the 123gr AMAX.
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