I took my Ruger out to the range today and I think that I've found a load that it really likes. The last time out I had worked up the load and found that the best lead seemed to be 35.7gr of Varget behind a 50gr Nosler Ballistic Tip BT.
So to comfirm I loaded up 100 rounds to play with and so I could get a decent amount of data regarding the load. Needless to say, I'm VERY impressed with the results. I did go ahead and glass bed the reciever with Acra-Glas, and I adjusted the trigger to minimum pull weight and creep. The trigger still has a bit of creep left because any further reduction causes inadequate sear engagement. I'd say that the pull weight is about 2 lbs.
I shot these groups with the following load:
35.7gr Varget (each charge weighed)
50gr Nosler Ballistic Tip BT
W-W brass (trimmed to uniform length, fireformed to chamber, flashholes deburred and primer pockets recut to uniform depth).
CCI BR-2 Benchrest LR primers.
Mean velocity: 3711fps measured 13ft from muzzle.
I fired 13 five shot groups, with the remaining 35 rounds used to plink clay pigeons off the berm at 225 yards!
All groups were fired at a known distance of 200 yards.
I'm not going to post all of the data from each target, unless someone asks, nor will I post the pictures unless asked in the interest of bandwith for those of us stuck with dial-up.
I measured both the whole 5-shot group, and the smallest 3-shot group within each 5-shot group which is denoted by enclosing the measurement in parentheses.
Smallest Group: 0.689"/0.345 MoA ; (0.210"/0.105 MoA) !!
Largest group: 1.829"/0.915 MoA ; (1.186"/0.593 MoA)
Mean group size: 1.259"/0.630 MoA ; (0.559"/0.280 MoA)
Standard Deviation: 0.348"/0.174 MoA ; (0.272"/0.136 MoA)
Extreme Spread: 1.140"/0.570 MoA ; (0.976"/0.488 MoA)
I did find out that my rifle doesn't take kindly to cleaning...The largest two 5-shot groups were fired right after I'd cleaned the bore, and it was pretty erratic. After about 10 more shots it settled back down and returned to shooting very well. But even so the largest group never exceeded 1 MOA, so I'm still very pleased.
Yeah, Ruger accuracy sucks, my butt!
Mike