Hey guys. Im having hell at 800 with the 155 A-Max. Here is my load, 308 Win, 155 A-Max, Winchester Brass, CCI primer, 46.3gr RL-15, Remington 700 20" barrel. Chrony says I am averaging 2775fps with this load.
Actual dopes
100 - 0
200 - +0.6
300 - +1.3
400 - +2.4
500 - +3.9
600 - +4.9
700 - +6.3
800 - ????
JBM says to get that trajectory I the bullet is actually going only 2600fps using the G7 BC of .212, and it is super sonic to about 900 yards.
Yesterday I was working the rifle out and had no issues getting a modest group out to 700. The wind was absolutly calm, there was a storm about 6 hours out so I was shooting in the calm before it hit. Im shooting a cardboard box that is 2 feet wide and 6 feet tall with a black aiming point at the top. When I moved back to 800 I shot 5 rounds and went down to check the target and there were no shots on the target with 7.3mils dialed. I thought that was weird, and maybe I still shot under the target?? So I went back to the line and dialed it up to 7.7mils and shot another 5 rounds. Still nothing on paper. WTF?? SO I thought maybe I am over adjusting and shooting over the target. So I dialed it back down to 7.0mils and put an aiming point in the middle of the card board and shot 5 more. This time I got one clean hole about 0.8mil low and one keyhole about 1 mil low but no clue where the other 3 shots went. What the hell is going on?? Is the bullet going subsonic earlier than I think and massively destabilizing and going all over the place? Does the 155 A-Max suffer the same issues as the 168 SMK when it goes subsonic? Ive got some 155 SMK 2155s, should I try them? Their G7 is only 0.002 higher and they are not as consistent bullet to bullet as the A-maxs.
Actual dopes
100 - 0
200 - +0.6
300 - +1.3
400 - +2.4
500 - +3.9
600 - +4.9
700 - +6.3
800 - ????
JBM says to get that trajectory I the bullet is actually going only 2600fps using the G7 BC of .212, and it is super sonic to about 900 yards.
Yesterday I was working the rifle out and had no issues getting a modest group out to 700. The wind was absolutly calm, there was a storm about 6 hours out so I was shooting in the calm before it hit. Im shooting a cardboard box that is 2 feet wide and 6 feet tall with a black aiming point at the top. When I moved back to 800 I shot 5 rounds and went down to check the target and there were no shots on the target with 7.3mils dialed. I thought that was weird, and maybe I still shot under the target?? So I went back to the line and dialed it up to 7.7mils and shot another 5 rounds. Still nothing on paper. WTF?? SO I thought maybe I am over adjusting and shooting over the target. So I dialed it back down to 7.0mils and put an aiming point in the middle of the card board and shot 5 more. This time I got one clean hole about 0.8mil low and one keyhole about 1 mil low but no clue where the other 3 shots went. What the hell is going on?? Is the bullet going subsonic earlier than I think and massively destabilizing and going all over the place? Does the 155 A-Max suffer the same issues as the 168 SMK when it goes subsonic? Ive got some 155 SMK 2155s, should I try them? Their G7 is only 0.002 higher and they are not as consistent bullet to bullet as the A-maxs.