P17 308 new loads for the new year help.

527vamint · December 5, 2016

New year coming soon,I want to get my p17 spot on,I'm looking at selecting a more appropriate bullet for it and cutting costs a bit.

Winchester p17 308

27" barrel 1:14 3/4 twist.

I'm shooting at 100m mainly and 300m every other month.

Currently I'm using 46g of n140 155g amax and cci br primers in lapua brass @ around 2890, the brass is nearing the end of its life so I'm changing to ppu brass,which I have collected. Im getting a 2" group with peepsights and 3/4-1" group scoped of a bipod.

The p17 will be shot mainly free hand off the elbows,10 rounds in 100 seconds.

Can anyone recommend any cheaper powder,primers and a bullets.

Obviously I'd rather be more accurate than sacrifice accuracy for cost.

It's a 1:14 3/4" twist sorry.

Cheers

GeorgeB · December 5, 2016

The twist rate of 14.75" is a limiting factor in your choice of bullets which will be fully stabilized. The Berger Twist Rate Stability Calculator gives a gyroscopic stability factor for the 155gr Amax with this twist rate of 1.09, which is considered "marginally stable". The minimum recommended twist for this bullet is quoted as 1 in 12.5"

You will get better results with a shorter bullet, such as the 135gr or 150gr Sierra Match King.

527vamint · December 5, 2016

Thanks for the info,tried 155g lapua senars,not great,it liked surplus ammo,which was burden primed with a silver coated bullet 147g in a brown cardboard box with Russian righting on? . I suspected a lighter bullet would be better,just using up what had,then stuck with it.

Davy · December 5, 2016

P17 (M1917) so I assume originally chambered in 30-06 and converted to target rifle at some point. 1:14 would suggest an older barrel, maybe even a S&L cut rifled so it would be worth slugging it first off as it might be a bit tight. Personally from an accuracy view point I would shoot it with SMK #2155 155 grain bullets and keep the MV down as it will probably not appreciate hot loads. A modest load of TR140/RS50 would do the trick and PPV brass is fine if you have a ready supply.