308 vs 30-06 and other rounds? WHY is a 308 better?!?

[Bart B]

Originally Posted by Michael Eichele

25 years ago with the bullets and powders available it took the large magnums to hit the 1000' pound mark at 1000 yards. Now there are 308 loads that hit with 1000 pounds at 1000 yards. Granted, this is the upper limits but illustrates how far we've come with bullet design and velocities.

With Sierra's HPMK bullets in a .308 case, they'll need the following muzzle velocities to hit with 1000 ft/lbs at 1000 yards in standard atmospheric conditions:

190, 3130 fps

210, 2700 fps

240, 2405 fps

How much of what powder will do that in a .308 Win. case with any barrel length up to 30 inches long and what peak pressure are they averaging?

[Michael Eichele]

With RL17 or VVN550 under the 208 AMAX, 2650-2700 is possible with 26" custom barrels. I don't know the pressures but have run them at these speeds with easy normal extraction, primers not cratered with no ejector marks on Remington cases. Both have flat pressure curves which make this possible. It seems though that R17 has the easiest curve but 550 settles in the case better for shorter COALs.

[Bart B]

Originally Posted by Michael Eichele

With RL17 or VVN550 under the 208 AMAX, 2650-2700 is possible with 26" custom barrels. I don't know the pressures but have run them at these speeds with easy normal extraction, primers not cratered with no ejector marks on Remington cases. Both have flat pressure curves which make this possible. It seems though that R17 has the easiest curve but 550 settles in the case better for shorter COALs.

I think such loads are a bit too much for .308 cases. And using the least accurate method known of "measuring" peak pressure as you do (easy normal extraction, primers not cratered with no ejector marks) is a UAUWAG in my opinion. But load ammo to whatever level meets your objectives.

[Michael Eichele]

Bart, I will. thanks for the permission.

All the loads I use are normal levels. I have experimented with many loads but usually run my go to loads much less that those I have topped out at. My 208 load is 2500 despite having pushed them to 2700. For modern components and longer than standard barrels 2500 is pretty mild.

The point here is that what we do today and what we can do is far more advanced than what it was 25 years ago.

FWIW, German Salazar took the 185 over R17 to over 2700 while well under standard pressures. 54000+\- PSI if I recall. That being the case, the 208 over R17 at 2500 FPS should be pretty reasonable. Maybe not maxed but still impressive for the lowly 308.

[Bart B]

Originally Posted by Michael Eichele

All the loads I use are normal levels. I have experimented with many loads but usually run my go to loads much less that those I have topped out at. My 208 load is 2500 despite having pushed them to 2700. For modern components and longer than standard barrels 2500 is pretty mild.

The point here is that what we do today and what we can do is far more advanced than what it was 25 years ago.

FWIW, German Salazar took the 185 over R17 to over 2700 while well under standard pressures. 54000+\- PSI if I recall. That being the case, the 208 over R17 at 2500 FPS should be pretty reasonable. Maybe not maxed but still impressive for the lowly 308.

Will such loads put 20 shots inside 10 inches at 1000?

[Michael Eichele]

With the accuracy/consistency level of my rifle/load combo, it would do it. The weak link of course would be the shooter. Given manageable wind and mirage, I would back this claim up if you want to visit Alaska any time soon. I'll be doing a 600 yard and 1000 yard match later this year. 20 rounds each. I guess we'll know for sure then. But I sure as hell wouldn't bet against it.