knowledge_is_power
Inactive
First off let me say that I'm fairly new to the precision shooting world. I have a Rem 700 .308 with a 20" 1:10 twist. I JUST started reloading and am experimenting with it still. The other day I took 30 rnds out to test fire with my rifle and chronograph. I loaded them with once shot casing I had, 40g of Rx-15 and Sierra 168 grn BTHP. It was a hotter humid day and I started off shooting upwards of 3200 fps. After about half way through, my velocity dropped to around 2300 fps. I snaked my barrel two times five times each with no change. What gives?