308 Information
Here is a discription of my rifle, Cz 550 American 308 sporter with 24" barrel, 1in 13 rifeling twist. Rifle is fitted with a 4to 12 x40 Ao scope and Cz mounts, all up the outfit weighs 8lb 12ozs. I bought the rifle new and epoxy bedded the recoil lug area and polished the trigger sears and lightened the trigger to 2 3/4lbs. Rifle was extensievely tested with 6 different projectiles and loads, using seating depth as the main tuning method and virtualy no changes to powder charges. When I felt everything was right I loaded up 3 rounds of each load and fired them off in one session at two targets and here is the result. Definately no wallet groups here as they were all fired in one session with no repeats at my 100yd target frame. Here I have listed load details, height of bullet strike above the aiming mark, accuracy on the day and overall length of loaded rounds. As a rough guide it may be noted that the o.a.l of a round loaded with a 165g Sierra hollow point touching the lands is 2.874". I do all my seating depth testing in metric but have converted them back so that you guys can understand what I am about. 110g Sierra 50g W748 WLR Lapua brass O.A.L 2.539"accuracy .398"for 3shots 2'' above point of aim. 165g Sierra 45g Varget REM91/2 O.A.L 2.676" .25"for3shots 1.3" above point of aim. 168g A MAX 45g Varget CCI 250 O.A.L 2.855" .758" for3shots 2" above point of aim. 125g Sierra 48g AR2206H REM 91/2 O.A.L 2.756 1.375" for 3shots 1 3/4" above point of aim(Group should have been around .5" but had a seniors moment and fired one shot a wrong corner of square bullseye) 130g Speer 48g AR2206H REM91/2 O.A.L 2.717".4" for 3shots 3.5" above point of aim. 180g REM Corelokt 44g Varget WLR O.A.L 2.676" 1.34" for 3shots 0" above point of aim. It should be noted that many of these bullets are seated .196" or more away from the lands. The three light bullet loads clocked around 3,070fps, the 165s 2640 fps and the 180s 2490 fps. Hope this helps Reguards Murphy.