308 Ackley improved, .. can if ya want...it was used many yrs ago. I believe the average gain was about 50 fps. I have played with the standard 308 case, alot and improving its performance, so now use a long action so I can seat bullets out to 3.4"...but use around 3.2" and feed out of 30-06 detachable mags in MPA chasis...and now use 8 or 9 twist barrels and 200 to 230 gr bullets. Running 200 gr SMK .715 BC bullets over 2850 fps and 230 ATIP .823 BC at 2620 fps and 225 ELDM .777 BC at 2675 fps. All standard 308 Lapua cases in 30" Bartlein barrel. Increase the powder capacity by seating bullets way out, and increasing the performance. My 200 SMK load...Over 3600 ft/lbs of muzzle energy...at 1000 yards drop 25.6 MOA 1700 fps remaining, 1285 ft/lbs and only 55 inches of wind deflection in 10 mph cross wind. Not bad for a 308 case. I use my standard 308 reamer for the Lapua neck thickness and no neck turn... then throating reamer to move the throat to where I want the bullets to be in relation to its position in the case. Built a fixture for this so that a stop can be set with feeler gauges to go the exact distance needed. So if added to gather with an improved case 2900 fps with a 200gr 715 BC bullet may be possible in your 308 improved case and a 8 twist 30" plus barrel and long action...cause I've run em at 2880 fps pushing the envelope, no blown primers. Lol... have fun...but always try to use power when trimming or neck turning cases...I use a lever collet fixture and a Bridgeport mill, so I can take 308 or 30-06 to 8.6 Blackout in about a second.
So far the 8.6 blackout is a dud, no where as versatile as the 300 blackout...the 3 twist is too much, high velocity bullets explode immediately, like inside your muzzle break, and tear chunks out of the chronograph bayonet. It needs an 8 twist IMO to be more versatile for the average shooter... and that's all I know about that...still exploring and experimenting.
So far the 8.6 blackout is a dud, no where as versatile as the 300 blackout...the 3 twist is too much, high velocity bullets explode immediately, like inside your muzzle break, and tear chunks out of the chronograph bayonet. It needs an 8 twist IMO to be more versatile for the average shooter... and that's all I know about that...still exploring and experimenting.
