Well, with the 6WOA, my main objective was to get back to the velocities I used to get with some previous lots of Varget. The current lot I have is 50 fps slower with the same charge behind a 107SMK. I use to get about 2720ish fps in the 6WOA but was only geting about 2670-2680 fps with the current lot of Varget with the same charge (27.1 grs. of Varget). This wouldn't be a real problem, but I do not have enough room in the case to fit enough of the current lot of Varget to get back to my old velocity, I need to be able to fit 27.5 grs and can't ( I can with SSA brass, but that brass just doesn't cut it). With 26.6 grains of AR-Comp, Wolf LR primers in R-P brass, I am getting an average of 2716 fps, ES-12, SD-6. I could probably increase that velocity some, but my objective was to get to my old velocity and I achieved that without having a super compressed load. I dropped the charge to 26.5 grs. of AR-Comp, merely because my powder measure throws that charge and I am getting an average velocity of 2710 fps, ES-23, SD-8, but shot an honest 1/4" 5 shot group with this charge. 2000-MR would probably give more velocity, and somewhere down the road I may try it, but I'm concentraiting on the RAT right now trying to decide on the load and powder for it.
With the 6 RAT,
29 grs. of this slow lot of Varget gives me 2763 fps, ES-46, SD-18, with Wolf SRM primers in AA Lapua brass and maybe just under 1/2" 5 shot groups.
29.5 grs. of Varget gives 2807 fps, ES-17, SD-6, and also just under 1/2" groups. This is right on the edge for me and 29.2 grs. I think is a better load pressure wise.
28 grs. of H4895 gives me about 2748 fps, ES-20, SD-7 and also right at 1/2" groups.
And, AR-Comp, 28.4 grs. WSRM primer, AA brass, average of 2821 fps, ES-11, SD-4, less than 1/2" groups, close to 3/8" group.
I did not do a huge amount of test loads, I just wanted to see what some different powders would do and then I just started shooting matches as the real test.
I am currently shooting 28.1-28.2 grs of AR-Comp because I am trying to see how the brass holds at that level. I kind of pushed the pressure on some of the brass working up loads with different powders and some of the primer pockets are a little loose on my 600 yd brass. I will try and shoot a prone match in the next few weeks to see how some of the other brass does that has real tight pockets to see how the pressure is at this level then maybe try it again at 28.4 grs. I am just shooting the same powder charge of AR-Comp behind my short line lines with Hornady 87 BTHP's and they shoot great, I haven't even chrono'd them to see what they are doing, but really don't care. My goal was to shoot 107s at around 2800 and be easy on the brass with accuracy, and I think I am accomplishing that. I am sure 2000-MR would increase my velocity and again, want to work that up some time, but right now I'm just trying to get use to the new upper, cartridge, and Warner rear sight clicks after shooting an RPA for so long. I have also turned the necks on my 600 yd. brass to see what that may or may not accomplish.
My RAT is a 27" Krieger, and the upper is from Holliger, with the 2 1/4" handguard. I have only shot it in 2 matches across the course and no prone matches yet. I have only manage a 195, and 196 in slow prone with it so far, which is a tad below my usual average of about 197, but I think that will come back shortly, I just need a few more matches to get everything settled in. Not to mention that I'm just finally starting to get a reasonable offhand back, but that's another story! Dave
PS: I'm sure the 28.4 grs of AR-Comp is fine, and probably even a little more, but I want to see what happens at my current level first before pushing it back up with the 107s.
