Re: .308 making the distance?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LawnMM</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MAT 4-82</div><div class="ubbcode-body">You don't say what your platform is and that can make a difference on recomendations. lowlights suggestions are very good for .308 overall. You mention 850yd accuracy deterioration. Is this verified group size or are you just getting fewer hits on steel at this distance +? Couple of posters mention the transonic issue with lighter bullets but this is more an issue with gasguns
(USMC used to use 168s at 1K in their magnums for example)and the Palma guys do well with the 155s. If mag length is a factor for you then VLDs might not be a good option. </div></div>
Its an issue of the bullet going transonic, I'm not sure how it's going to matter what its fired out of, if the muzzle velocity is the same bolt vs gas gun won't matter. The 168 Sierra is pretty notorious for transonic instability.
The 155 Lapua does much better, and has a much better ballistic coefficient, which is why its accurate at range despite its lighter weight. Its a well designed bullet. Berger produces 175gr projectiles specifically designed to be stable through the transonic part of the bullet's flight. If you plan to shoot at ranges beyond what your round will still be supersonic they may be a worthwhile investment.
For most people, I think the standard offerings from Sierra and Hornady in the 175 and 178 grain varieties will be supersonic farther than most people can shoot accurately. For example, Hornady designed their 178 HPBT to be supersonic to 1200 yards at sea level. If you plan to shoot farther than 1200 yards, at which point the transonic issue is a concern, there are better calibers and projectiles to use than 308.
A 208 Amax at 2500fps here in Colorado is supersonic to like 1600 yards. If I planned on doing a bunch of shooting at the mile marker, I think I would look much harder at the 300 Winchester Magnums and .338 Lapua Magnums to get it done with more ease and repeatability. This is to say nothing of the fact that my shooting skills probably aren't adequate for that task even if my rifle is.
For 0-1000yds in 308, just use a 175 or 178 grain bullet and be done with it.
Rich </div></div>
My point is that the max safe MV in most cases can't be the same. A bolt gun can utilize higher pressures than a gas operated semiauto and thus achieve higher velocities necessary for stability. That's why I gave the example of 168s in USMC .300 mags and ask about the rifle. A 208out of a gasgun would be a high pressure load @ 2500fps. I believe those shooting 155s at 1K are pushing them around 2900+ If the OP has a boltgun other bullets are feasible. If he has a gasgun not so much. That's why I ask
