Bullet weight??

[Meaty]

Hello, Can you folks help me identify a good bullet weight for my 308 Winchester Stealth II. It has a 26" barrel with a 1 in 10 twist. I am shooting paper at 600 yards but would like to push it out to 1000 in the future. I have been looking at some 185 Scenars but here in England the price of reloading components is so expensive I dont want to make a costly mistake! Any advice to this newbie would be appreciated. Thanks. ???

 

[Laurie]

Don't use the 185gn Scenar for 1,000yd - it's a good bullet but low BC compared to many competitors.

The 155gn Scenar is the bullet in the Lapua .30 cal range for very long-range shooting and usually does well even in a fast-twist barrel like yours. However, the bullet I would really recommend is the fairly new Berger 185gn Match BT Long-Range (NOT the 185gn VLD that takes a lot more work to get to shoot well). This is a high BC bullet that is not too difficult to tune for good accuracy. I use Viht N550 with it in Lapua or Norma brass. American shooters speak highly of the Berger 175gn Match BT model in .308W too, but I haven't tried that one myself.

The Berger is an expensive bullet unfortunately and may be hard to get hold of. Try Norman Clark in Rugby or Tim Hannam in North Yorks. Fox Firearms in Stockport gets them too, but I've just got him to put his remaining 185s aside for me.

For shorter range work up to 600yd, give the 175gn Sierra MK a try with N150, VarGet or IMR-4064. This is an easy to tune bullet that works well in most barrels and often gives outstanding accuracy. The 190gn and 200gn Sierra MKs are good long-range bullets, not as technically advanced as the Bergers ballistics wise, but good sound designs with a proven record in long-range shooting.

There are three very high BC modern secant-ogive designs available that your 1-10" twist will stabilise - the 208gn Hornady A-Max, and 210s from Berger and Sierra. All three are VLD type bullets that can be very fussy about seating depth / jump usually needing to be seated so they are chambered hard into the lands to perform well.

Whatever you do, don't use 168s from Hornady, Sierra, Speer, or Nosler at 1,000yd in .308W - they become subsonic and unstable at around 800 yards, likewise A-Maxes other than the 208gn model, or the 180gn Sierra MK. All of these bullets have very steep angle boat-tail rear ends that stabilise the bullet quickly for short range shooting, but destabilise them at long ranges as the velocity drops towards the sound barrier.

Laurie,
York, England

 

[Yellow11]

Tips aren't really that expensive here in the UK...

I suggest you buy a copy of Bryan Litz books on Applied Ballistics and you will end up saving yourself cash and learn to understand the logics that will answer your questions. It also lists G7 BC...

You need to end up with a gyroscopic stability factor of not less than 1.4... A .308, with a 10" twist will fit a lot of tips. Assuming a MV of 2800 fps, then Bergers 190 VLD will give you a GS of 2.3 and the 210 gr gives you a stability factor of 1.7, even the 240 gr Sierra Match king will turn in a GS facor of 1.6,

So really, any heavy tip will work for bucking the wind at 1000 yards.