roysha
09-18-2013, 03:44 PM
I'm not sure I'm posting this in the right place but since most of the current crop of AR platform .223/5.56 rifles seem to have 9" twist or tighter I thought it might be appropriate here.
After comparing the 69 grain Sierra Match and the 55 grain Sierra SPT (55 grain being more or less the accepted "Standard" weight) using the Sierra ballistic program, in virtually all categories except wind drift at extended ranges, (400 yards or more), the 55 grain bullet exceeded the performance of the 69 grain bullet. This was using velocity compared to velocity, (ie. both fired from the same length barrel and not comparing a 16" M-4 to a 24" Varmint). I can only imagine what the 70+ and 80 grain bullets give up.
Assuming the accuracy is the same for both bullets, and having shot many rifles with both these bullets I believe that would not be an issue, I am at a loss to understand all the fuss about the longer, heavier bullets. I see nothing but a down side to pretty much anything more than 60 or so grains. Perhaps there is something I am missing here and someone could explain it to me. I am truly curious.
One last thing, before anybody jumps in with their 22-250 or Swift results, please reread the title.
After comparing the 69 grain Sierra Match and the 55 grain Sierra SPT (55 grain being more or less the accepted "Standard" weight) using the Sierra ballistic program, in virtually all categories except wind drift at extended ranges, (400 yards or more), the 55 grain bullet exceeded the performance of the 69 grain bullet. This was using velocity compared to velocity, (ie. both fired from the same length barrel and not comparing a 16" M-4 to a 24" Varmint). I can only imagine what the 70+ and 80 grain bullets give up.
Assuming the accuracy is the same for both bullets, and having shot many rifles with both these bullets I believe that would not be an issue, I am at a loss to understand all the fuss about the longer, heavier bullets. I see nothing but a down side to pretty much anything more than 60 or so grains. Perhaps there is something I am missing here and someone could explain it to me. I am truly curious.
One last thing, before anybody jumps in with their 22-250 or Swift results, please reread the title.