I have 4 new bricks of Eley Match .22lr & I am starting a new 'Node Search' for the CZ452 @ 100 yards. I have a Harrolls Tuner on the CZ but have removed the x-tra 6 ozs. weight, I'm running just the tuner alone.
Why not do this at 50 yards?
At 50 yds. you'll get tight little bug-holes...but...It is said that 50 yd. tuned groups will open a minimum of 3X at 100 yds. I didn't believe that but after testing earlier this year, I found that it is true.
I believe this is attributed to the extra 50 yd. range that the wind has a better chance to influence trajectory.
Other factors, ie. the standard deviation of the ammo, the shooter, the rifle & associated bench equipment...even the bench itself add to making that 50 yd. group 'swell' to 3X larger.
It's just a 'hunch' I have but, why not tune at 100 yds.?
I believe all the variables that influence groups have to be fine tuned together...my goal this next year is to shoot 5 ea. 5 shot groups and have the average size of those groups be consistently less than .400".
This is the first effort to tune this new lot of Eley Match ammo, I started with a span of tuner settings I've used with other lots because I buy only the ammo that is factory rated at 1055 fps. In the CZ they average 1080 fps because of the match chamber.
For me...this is a new method of Node Search, instead of multiple 2 shot groups at each tuner setting I am using 3 shot groups, that gives me a better estimation of the vertical spread. Then look for the most promising setting, possible nodes...and go out and test with the 5 shot groups.
Here each row is a specific tuner setting (spanning .039" down to .035" on the tuner), wind direction and velocity are noted at each bull along with the size of the 3 shot group (I am not compensating for wind drift & allowing them to deviate, this adds data for when I use Kentucky Wind-age and go for my goal)...then those groups are all averaged and written in the left-most column of the card.
After all that, it's a lot of Mulling as I think about the variables that influenced this testing and decide on the parameters of the next test...in this case, I think I need to look at some groups with 2 or 3 thousandths more length on the tuner...ie. .040" ~ .042" or so, we'll see?
I know this is a bad time of year to think about outdoor shooting but here in Northern California I still have some pretty good shooting days ahead until Spring.
At my age 72, it is rough to deal with the cold weather but it is primarily those days where I have a more mild wind that I can get meaningful tuning data.
After Spring, when it starts warming up some, I'll have days where the wind is actually 0 mph or barely detectable on my face...that's when I expect to see this work pay off.
No...I don't compete...this is not preparation for next season, this is just activity in the latest Rabbit Hole I found a couple years ago.