hitman1012
06-26-09, 16:19
I have a new LMT MRP rifle with both a 6.8 barrel and a 5.56 barrel. I did a bunch of testing today and here is what I found. The 6.8 barrel has been converted to SPC II and was cut down to 14.5" by ADCO and had a Vortex pinned on. I read what Santos said, so I figured it would help with the gas issue. Well, it still ejects at about the 1-2 O'clock position with the stand. buffer. I cronoed a few diff. loads also. SSA 90 grain Var. averaged 2760 fps.
30 Grains of H322 with 110 grain Horandy (not A-Max's) in SSA brass CCI 400 primers
2594
2608
2594
2596
2609
and grouped right at 2 inches at 100 yds using an Aimpoint. I am gonna stick with this load. Seemed a little hot, but no real crazy pressure sighns.
Then I took off that barrel and put on the 14.5" 5.56 barrel CL. Cronoed SSA 77 OTM and wow! It likes!
2700 average and grouped right at an 1 1/4 same sight.
24.6 grains of TAC in Winch. case and 77 SMK- averaged 2650
That load is way over max, so do not duplicate without starting lower.
With swapping the barrels the 6.8 barrel changed the POI 5" lower, changed the 5.56 back over and it was 1 moa right from where it was before with the 5.56 barrel.
I also tested my Noveske N4 Basic, to compare the two. I will post that later, but the LMT is more accurate and crono's higher.
Also, never missed a beat with either caliber.
Question: what difference does it make if the 6.8 brass ejects there rather than 3 O'clock???? Is it a problem or gonna be problem. I am very happy with those #'s and do not want to change it.
Thanks
30 Grains of H322 with 110 grain Horandy (not A-Max's) in SSA brass CCI 400 primers
2594
2608
2594
2596
2609
and grouped right at 2 inches at 100 yds using an Aimpoint. I am gonna stick with this load. Seemed a little hot, but no real crazy pressure sighns.
Then I took off that barrel and put on the 14.5" 5.56 barrel CL. Cronoed SSA 77 OTM and wow! It likes!
2700 average and grouped right at an 1 1/4 same sight.
24.6 grains of TAC in Winch. case and 77 SMK- averaged 2650
That load is way over max, so do not duplicate without starting lower.
With swapping the barrels the 6.8 barrel changed the POI 5" lower, changed the 5.56 back over and it was 1 moa right from where it was before with the 5.56 barrel.
I also tested my Noveske N4 Basic, to compare the two. I will post that later, but the LMT is more accurate and crono's higher.
Also, never missed a beat with either caliber.
Question: what difference does it make if the 6.8 brass ejects there rather than 3 O'clock???? Is it a problem or gonna be problem. I am very happy with those #'s and do not want to change it.
Thanks