I was bored so I decided to make a subsonic load for my 7mm saum. I was going to buy some larger round nose bullets but I figured with the ammo shortage I should use something on my shelf. I ended up with 11 gr of trail boss under 139 hornady interlock. It chronoed at 1060 and sounds like a popcorn fart.
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Nice, hows the accuracy?
Haven't had a chance to test accuracy yet just loaded one of each 14, 13, 12, 11, 10.5 of trail boss. Ran them through the chrono. 11 was at 1062 and 10.5 was at 998. Next time at the range I will test accuracy.
I have been wanting to make a subsonic load for my 7wsm and 7saum. Nice timing. Do you only put the powder in the case? No filler? Always heard you had to add so kind of filler with that small of amount of powder.
Trail boss is a very bulky powder. I think the case filled to case neck was about 17-18 gr. I just tried sw 160 sgk with 12gr and got about 950 ish. I should be able to add almost to 13gr and still be subsonic. I did see some velocity spreads with the 11 gr and 139s. 1 of 10 would break sound barrier.
I need to test accuracy with the 160s. Hopefully with more case fill I will get better velocity spread.
