FWIW, I'm getting 2,665fps from Black Hills 139gr Scenars in 260REM in my 20" LMT MWS that clock 2,755fps out of my 23" GAP bolt gun. That works out to about 30fps per inch change for the 3" difference in barrel length. The LMT 260 is a 1-9 twist unlike their 6.5CM, so I'm stuck with the 130gr...