To start off I am relatively new to long range shooting but I am very excited to learn. I have an sps tactical aac sd in .308 as my tool with a mil/mil scope. Tonight I had to run down to my farm and meet a guy delivering a bull so I figured I would try my rifle at distance. I have a 100 yard zero and shot before out to 225 yards at some 3" steel and did well. I don't have access to a chrono so I was hoping tonight I could get on paper and break down my velocity myself for future shooting by plugging in velocities until I was close to the drop I was experiencing.
Well tonight I set up my target and went back to range it...704 yards. I plugged the numbers into strelok taking a guess at 2575 fps from the 20 inch barrel and sent 3 rounds of FGMM 168 down range. It was getting dark so this was all I was able to do. Upon inspecting the target I was pleased and disappointed. My windage was 8, 9, and 10 inches right for the three shots so to me they were stacked really well. These could have been me as I was not paying attention to the level as I was sort of in a hurry. The disappointment was the elevations. All were high as I suspected they would be. When shooting at the steel at 225 with the same velocity in strelok I was consistently hitting high. The problem was the spread on the 3 shots. I was high by 9, 16, and 23 inches. Roughly 2 moa or a 14" spread. I was shooting prone, off a bipod, using a coat for a rear rest. I know, not the best scenario...but I have an idea on what is causing the vertical movement.
When I get behind the rifle I try to line everything up and then shoulder the rifle. First thing I always notice is my heartbeat. Am I shouldering the rifle wrong to be seeing my heartbeat? My heartbeat is definitely a vertical movement in the scope. If I hold the rifle fairly tight it is minimized but I have a feeling its still there and a distance of 700 yards will start to show that. What else would cause the vertical stringing? I don't have the $$$ available for training/classes but there is no way I will be giving up.
I also calculated the corrections I need for the next time I give it a go at this distance....does .3 mils left sound right (it was totally calm with no wind in the valley tonight, so this would be assuming similar conditions next time) and if I use the 16 inches high hole as the average for elevation .6 mils down sound correct? This would give me a dial of 6.2 mil at 700 which to me seemed a little hot for a 20 inch.
Any help is greatly appreciated!
Well tonight I set up my target and went back to range it...704 yards. I plugged the numbers into strelok taking a guess at 2575 fps from the 20 inch barrel and sent 3 rounds of FGMM 168 down range. It was getting dark so this was all I was able to do. Upon inspecting the target I was pleased and disappointed. My windage was 8, 9, and 10 inches right for the three shots so to me they were stacked really well. These could have been me as I was not paying attention to the level as I was sort of in a hurry. The disappointment was the elevations. All were high as I suspected they would be. When shooting at the steel at 225 with the same velocity in strelok I was consistently hitting high. The problem was the spread on the 3 shots. I was high by 9, 16, and 23 inches. Roughly 2 moa or a 14" spread. I was shooting prone, off a bipod, using a coat for a rear rest. I know, not the best scenario...but I have an idea on what is causing the vertical movement.
When I get behind the rifle I try to line everything up and then shoulder the rifle. First thing I always notice is my heartbeat. Am I shouldering the rifle wrong to be seeing my heartbeat? My heartbeat is definitely a vertical movement in the scope. If I hold the rifle fairly tight it is minimized but I have a feeling its still there and a distance of 700 yards will start to show that. What else would cause the vertical stringing? I don't have the $$$ available for training/classes but there is no way I will be giving up.
I also calculated the corrections I need for the next time I give it a go at this distance....does .3 mils left sound right (it was totally calm with no wind in the valley tonight, so this would be assuming similar conditions next time) and if I use the 16 inches high hole as the average for elevation .6 mils down sound correct? This would give me a dial of 6.2 mil at 700 which to me seemed a little hot for a 20 inch.
Any help is greatly appreciated!
