#1
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20VT AA1680 head scratcher
I finally got a hold of some 2200 and 1680 and tested some loads today. Using the same charges of 2200 in R-P and LC brass I essentially got the same velocity (brass made no difference). Doing the same thing with AA1680 I usedm18.5 grains in the R-P brass averages 3680 FPS. In the LC brass, 18.5 averaged.......4376 fps - the bolt lifted with no effort and no flat or cratered primers.- The POA was about an inch lower than the previous group. (All brass was neck turned 0.228-0.229 for my 0.232 neck).
Has anyone seen this with higher charges of 1680 with LC brass? Just wondering, I had excellent results with 2200 and it will be my primary powder and if I use 1680 I won't use LC brass. |
#2
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Quote:
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#3
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20VT AA1680 head scratcher
Something is off, check your chrony and run another couple. Should not be that much difference. Bill K
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#4
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Ditto......Chrony malfunction.....no way.
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#5
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For reference I ran 18.3 of AA1680 with 32’s out of a 26” Pac nor with 10” twist at 3975. New Lapua brass. Primers started to flatten on edges and started expansion at .200”. Not my best groups. Even if they were we were gonna take our foot off the gas. I don’t subscribe to the “4000 is safe” in a Vartarg club. Don’t mean to ruffle any feathers by saying that but “just sayin”.
Now, shooting 4000 with the 24 NTX is another story..... But I’d have to agree, check the chrony. |
#6
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This^^^^^^
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#7
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I will double check - since this was my backup chrono, it will be awhile before I can verify. They were the last 4 shots out of about 50 for the day. I hope it is the chrono as the last group was 0.43"
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