I have been working on my Ruger MKII 7mm mag for a while.
last weekend I shot a group of 4 inside an inch.
The load was w-w brass, cci 250, 65gr of rl22, 140 gr BT with a col of 3.365.
The load was not that consistant over the chrony so I thought I would try a different primer and play with the col again.
I loaded up the same load as above with the exception of the primer. I switched the primer to a Fed 215 and loaded col lengths in .005 increments from .005 away from lands to .020 away.
col 3.350 3.355 3.360 3.365
fps 2885 3007 2959 2985
fps 2963 3004 2976 2990
fps 2960 2999 2994 2958
fps 3002 3012 2972 3002
fps 2997 3002 2978 2950
AV 2961 3005 2976 2977
ES 116.6 12.69 34.40 52.7
SD 46.7 4.89 12.56 22.06
group 1.625 - .75 - .75 - 1.25
It was nice to see those results over the chrony. The last time I played with col I didn't have the chrony and based my col on the best group size.
I am finally happy with my 7mm. I almost sold it a while back now I am glad I kept it.
last weekend I shot a group of 4 inside an inch.
The load was w-w brass, cci 250, 65gr of rl22, 140 gr BT with a col of 3.365.
The load was not that consistant over the chrony so I thought I would try a different primer and play with the col again.
I loaded up the same load as above with the exception of the primer. I switched the primer to a Fed 215 and loaded col lengths in .005 increments from .005 away from lands to .020 away.
col 3.350 3.355 3.360 3.365
fps 2885 3007 2959 2985
fps 2963 3004 2976 2990
fps 2960 2999 2994 2958
fps 3002 3012 2972 3002
fps 2997 3002 2978 2950
AV 2961 3005 2976 2977
ES 116.6 12.69 34.40 52.7
SD 46.7 4.89 12.56 22.06
group 1.625 - .75 - .75 - 1.25
It was nice to see those results over the chrony. The last time I played with col I didn't have the chrony and based my col on the best group size.
I am finally happy with my 7mm. I almost sold it a while back now I am glad I kept it.
