Andrew Leigh
Member
You can look back in my posts and see that I recently debated whether to chase lands or not. So glad I did and I absolutely owe credit to gamestalker for the method of doing a powder work up close to the lands. Previously at 2.8" COAL my best was 0.8" with 40.9gr and 1.1" (@100yrds) with 43.6gr imr4895 in .308 under 168gr SMK's. After loading 0.010" off my lands and redoing a powder workup I got this:
0.375" center to center 4 shot group in the upper right with 41.2gr. As to mechanical vs pressure: I have no clue but awesome question and good read on the replies.
So effectively you are using the OCW method from Dan Newberry, very solid and effective method. I used to use that too but found it rather wasteful of ammo.
You appear to have another node at 43.2gr. You may want to load up and down by 0.2gr and explore that node as well.
Have you been able to replicate that 41.2gr. group?
I would love to test your loads against QL and see if we cannot get some consensus here. Did you chrony the loads? If so would you be willing to provide some data, if so PM me you e-mail address and I will send you a form to complete. I will then input the data into QL and see if the QL output corresponds with your actual data.