18" AR308/AR10 Velocities?

Ronin22

Sergeant of the Hide
Full Member
Minuteman
Aug 19, 2023
244
352
TX
Curious as to what others are seeing with 18" 308 155gr & 168gr. (Hornady)
Mine:
40F.
168 AMAX
43gr Varget
2.800"
2560fps ave

155 AMAX
41.5 IMR3031
2700fps (Admittedly hot in 75-85F.)

I know even the extreme line of powders will increase about 50fps in Summer weather. Maybe I need to stay at the 168gr 2560 to see 2600s at 75F?
 
Try some 2000MR or CFE223. Both ball powders and not the best temp stability but you will get more speed. I’ve also had really good luck with 155’s and 8208 which is relatively temp stable.
 
Your velocity for the 168's is reasonable and I wouldn't get hunting too hard for more. 2000-MR will get you more at the cost of being more temp sensitive.

With 3031 your 155 Amax velocities are a bit fast and will probably be a problem in warmer temps. Varget still works fine with 155's and would reduce this issue.
 
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Your velocity for the 168's is reasonable and I wouldn't get hunting too hard for more. 2000-MR will get you more at the cost of being more temp sensitive.

With 3031 your 155 Amax velocities are a bit fast and will probably be a problem in warmer temps. Varget still works fine with 155's and would reduce this issue.
Cool
That 3031 batch is labeled "Winter" lol. It shot the best with 5rnds .465". Everything else is over an inch.
I only have N135 and TAC for further load development. So far:

30F. 750ft ele
155 Amax
N135: 41gr, 2530fps
41.5gr, 2560fps
42gr, 2605fps (Try 42.5 and stop?)

TAC: 42gr, 2575fps
42.5gr, 2555fps (Weird) (Maybe try 42.7gr?)
43gr, 2685fps (Quite a jump with 1/2gr)

168 Amax
TAC: 41gr, 2455fps
42gr, 2525fps (42.5gr?)
43gr, 2605fps