Steve, thanks for the tips. I did try re-torquing the gas block screws more evenly and went back out with some Winchester Matchking 69-grain HPBT ammo [not Hornaday .223 match ammo (either 67 or 75 grain, have to check the box)]
. It did seem more accurate but I was shooting at 50 yards instead of 100 and the 2nd day it was less windy and not raining.
Let's say the cheap Federal ammo was 3-5" groups at 100 yards (rain, gusty winds) while the Hornaday match gave 0.75-1.5" groups at 50 yards (no rain, light breezes), which should translate to 1.5-3" groups at 100 yards. But I also figured out the 2nd day some of my trigger pulls are moving the gun around a bit even with front on sandbags. Maybe I need to try it in a Lead Sled to eliminate the human variability.
I want to find out how accurate my Mini can be with the good ammo then mostly go back to shooting the cheap ammo for fun. Here's my rough ammo cost breakdown:
Nice "match" ammo: $1.00-$1.50/round
Regular "cheap" ammo: $0.50/round
Walmart cheap Federal/Perfecta ammo: $0.37/round
Bulk reloaded ammo: $0.30/round
BTW by "cheap" I mean any .223 or 5.56 ammo I can buy for $0.50/round or less. It's usually Winchester NATO 5.56, PMC, Fiocci, Federal bulk pack .223, American Eagle, Aguila (made in Mexico), or Perfecta (made in Spain?). Someday I'll learn to reload my own ammo.
Looking at my 50-yard targets with a ruler, I shot 3 to sight-in (after removing and replacing the scope) then 4 3-shot groups resting the rifle on sandbags. The group sizes were decreasing, probably because I was getting better at pulling the trigger without moving the POI.
- Group 1: 1 7/8"
- Group 2: 1 1/2"
- Group 3: 1"
- Group 4: 11/16" (just under 3/4")
If I can replicate the accuracy of the last 2 groups at 100 yards, that should be 2" or 1.25" groups, and would make me fairly happy.