Question on what bullet to use in short barrel 308

[Pappy83]

I put together a short barrel .308 for my daughter to use in tactical shoots in our local area, she will need to shoot from 200yds to 700yards. The rifle is a Savage Precision Carbine with a 14.5 inch barrel with a fixed 2 inch muzzle brake. I loaded up 9 168smk loaded with 45gr and RE-15, and 6 Barnes 168gr match triple shocks with same amount of powder. brass was winchester. All the SMK loads shot under 1/2 inch at 100yds 3 shot groups measuring .320, .450, and .457. the 2 groups shot with the Barnes averaged .750. The velocity average with the SMK bullets was 2608 for the 9 shots fired, and the Barnes bullets was 2615. My question is I guess do both of these bullets velocities get her out to 700yds okay. The accuracy is there I figure but is the velocity. I was thinking maybe i needed to go to 155gr bullets. Thanks for the help I know the barrel is short she is very small and this size is perfect for her.

 

[scout1]

Pappy, have you double checked your chrono readings on another chrono. I ran your results through Quick Load and came up with 2437 fps using RE-15 and a 168 SMK at 85 Degrees station temperature w/ a 14.5' barrel.

I would drop down to a 155 grn bullet with IMR-3031 and work up from 42 grains to around 45 max. Anything above 85 degrees you will have to start lower in charge weight, I would drop .1 tenth of a grain for every degree in temperature above 85 for start. Use good judgement and watch for pressure signs as you work up. You can replace a rifle, but not your daughter.

2600 fps with a 155 grn bullet should be enough to get her to 700 yds while still maintaining supersonic flight stability. You never mentioned the twist rate on the barrel so I assumed a 10 twist.

Good luck, Jon

 

[Pappy83]

Yes i shot it through 2 different models, It lost only on average 90fps from when it was at 20inch stock. Also my Noveske 14.5 .308 AR is almost identical in Velocity with these loads. I have found they dont lose as much velocity as people think. The rifle actually shoots better groups now then when it was stock. I have a 16 inch savage tactical rifle in 300 win mag, the velocity fall off was larger with that. I will try the 155's then, we hardly ever get to 85 degrees here, actually it snowed last night, temp is 41 degrees right now. When i shot these groups it was 58 or so outside. Her twist rate is a 10. Thanks for your help, the rifle is really neat for her very compact and shoots groups like crazy, she will have to run with it from set up to set up, we have a deserted air base with 1000m range and bunkers it is neat. it really likes 175gr black hills ammo, I just figured it would not make 700 yards stable with that. here is a picture of the short rig.

 

[MikeyG]

From what you say I guess your daughter is fairly small. How well does she handle recoil? Remember in tactical matches she will get tired and have to fire many shots, some while tired.

A lighter bullet at the same speed will have less recoil so you could try some of the 120ish grain loads and try not to push them too fast.

These loads would be effected by the wind more but learing to read wind would be beter in the long run than getting a flinch.

Good job getting her into the sport. Hopefully we'll see some photos of her holding up trophys soon.