I got out yesterday to continue wringing out my new rifle.
https://rokslide.com/forums/threads/winchester-model-70-my-first-customized-rifle.428649/
In November I got the barrel broke in with shoot/clean/shoot procedure (which is maybe imaginary/unnecessary?) and then tested 4 different factory in 10-shot groups to see what shot best.
Today I returned to the range to confirm the zero with the best of those loads and to try to true the velocity based on the drop (I don't own a chrono). These are rounds #81-120or so thru the gun.
I fired 20 rounds in 4 shot strings (limited by magazine capacity & suppressor mirage) my 4th group I noticed the POI was a ways left. When checked the suppressor was about 1/8-1/16 turn loose and when tightened group 5 came right back in to match the others.
a composite of groups 1,2,3, & 5 (excluding loose suppressor) shows POI .05mil left, .08 mil low
a composite of all 5 groups (including loose suppressor) shows POI .11mil left, .06mil low
Given the uncertainty of the 1 loose suppressor group and otherwise mostly less than a click off POA I elected to leave the zero as-is for right now and will check again with another larger group at next range session.
16 vs 20 shot composite with my buddy's excel sheet:
I then went out to 370 (which was the furthest I could shoot to conveniently) and made a guess on velocity based on barrel lg: box velocity 2970 / 24" barrel, I assumed 2870 with my 20.5" barrel (25 fps/in)
I suck & told my spotter that I pulled my first shot in the pink group. then proceeded to shoot 3 more.
adjusted velocity in the 4dof app & changed up my dial from that and fired the yellow group.
I did not have time to shoot at any other distances but my hope for the next range day is to try shooting out to some random distances in the 250-500 range in an attempt to further confirm/refine velocity without a chrono.
just for fun I made an 8 shot composite of my two groups at 370 yds (mathing out the .2mil difference in dial to superimpose)
and even with my bad shot it's a 1.5MOA group which I feel pretty OK about.
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