TUNING a .22lr BR at 100 yards...

[OS OK]

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.

[nicholst55]

Very nice. I'd be interested to see your final results, after you've found your node(s). I'd like to see how your preferred setting works at 50 yards, just because!

[BLAHUT]

If you get your tuner to work at 100 when you go to fifty may be even tighter ??
I used a finger size block of lead with a piece of rubber around barrel and a hose clamp. Just takes time and good Reckords.
Now the question is does your gun like this ammo or is there a better brand out there ???
I chased this dream for years....... I found a lot number the gun liked, before I started with trying to tune, to get tighter.....

[steveu]

Nice write up and bench!

[dverna]

OS OK, it does not work that way. The best tuner setting for 50 yards will be different at 100 yards.

It is why tuners get adjusted for different ranges. I could not believe it until I saw an article on it.

If I can find the article, I will post it for you.

Found it. Look near the end if you do not want to wade through all the other stuff:

http://www.varmintal.com/a22lr.htm

[OS OK]

Very nice. I'd be interested to see your final results, after you've found your node(s). I'd like to see how your preferred setting works at 50 yards, just because!

Me too & I will eventually go back to the 50 just to see this.


BLAHUT...If you get your tuner to work at 100 when you go to fifty may be even tighter ?? ( I think it will be. )
I used a finger size block of lead with a piece of rubber around barrel and a hose clamp. Just takes time and good Reckords.
Now the question is does your gun like this ammo or is there a better brand out there ??? ( I can tune anything of quality but the SD's have to be 10 or less. )
I chased this dream for years.......

steveu...Nice write up and bench! ( Thank you. )

**********************

I think that making little improvements as I go along will all add to the 'best tune' I am looking for.
One thing I did before breaking into this new lot was to install a new striker spring...

The new spring is maybe 3/32's longer and suposed to have 10% more striking energy...this should help to stoke the fire and get a better SD. I have yet to chrono this new lot but that will get done. We have to know those numbers.

[OS OK]

OS OK, it does not work that way. The best tuner setting for 50 yards will be different at 100 yards.

It is why tuners get adjusted for different ranges. I could not believe it until I saw an article on it.

If I can find the article, I will post it for you.

I would appreciate that Don ... this is something I'd like to understand too. Thank You!
I think that I am dealing with the projectile leaving the muzzle on the up-stroke of the harmonic...this way the faster rounds with a flatter trajectory are hitting lower in a group & the slower exiting rounds have a slightly increased bore angle and arc higher and fall back with the faster POI's.

[dverna]

Charlie.

Added the link in post 5. Enjoy.

[OS OK]

OS OK, it does not work that way. The best tuner setting for 50 yards will be different at 100 yards.

It is why tuners get adjusted for different ranges. I could not believe it until I saw an article on it.

If I can find the article, I will post it for you.

Found it. Look near the end if you do not want to wade through all the other stuff:

http://www.varmintal.com/a22lr.htm

I made a big mistake Don..."I assumed something."

I had it in my head that once they had that POI @ 50 yards, that gravity would catch each of them and pull them to earth on the same down turn of the arc.
As it turns out the slower round will drop another .540" than the faster one.

I was close in my assumption but...'No cigar'! ...

The Slower tuned @ 50 yards...



The faster tuned at 50 yards...



I think I'll 'GUESS' on this...but I guess the tunes will be only about .005" apart on the tuner setting?

[tazman]

You guys are now well beyond anything I can do or help with.
I will continue to read and maybe ask a question now and again but this is something I simply can't do.
Enjoy your rabbit hole guys.

[OS OK]

You guys are now well beyond anything I can do or help with.
I will continue to read and maybe ask a question now and again but this is something I simply can't do.
Enjoy your rabbit hole guys.

Taz...you've had some pretty good ideas before...good info on barrel deflection @ 50 yards, stuff I never knew. Don't clam up on us now Buddy!

After all...this is a discussion & discovery thread, ain't nothing concrete here just yet.

[dverna]

Tazman, how someone has fun is not the same for everyone. I enjoy learning especially about shooting. I may not ever use what I learn but it is still knowledge. The link I posted demonstrates that. I learned something I will never use but it may help someone else like Charlie and Harry.

Charlie’s first thread convinced me going down the tuner rabbit hole was not for me. Still, I tried to contribute as best I could and I learned from his efforts. I love to shoot but am too cheap to play extensively with match grade .22’s. But I could tag along with Charlie and enjoy his journey. Just I will enjoy Harry’s efforts.

Charlie’s work took me into shooting quality PCP air guns. It came at a time when shortages and prices made CF shooting prohibitive. It has been a lot of cheap fun. Not for everyone, but works for me. I have a new project with the Daystate for next year and will post on it separately.

I hope you will continue to share your experience with us even if this seems too far down the rabbit hole.

[OS OK]

ANOTHER LITTLE ANNOYING VARIABLE...is that wind-age adjustment on the Caldwell Rock BR.

It's a spot where the Bean-Counters talked Caldwell into putting cheap plastic washers where a pair of bearings should have been placed. The washers wear, they are not smooth turning and the slack in the fitment causes an effect like 'thread lash'. The adjusting knob will pull the top rest to one direction and when you go to make a fine wind-age adjustment in the POA the knob has a slack of about 30º before positive engagement in the other direction.
You can tighten the nylock nut on the assembly firm enough to rid the 'thread lash'-slack but it makes the knob difficult to turn. That may not sound like a big deal but when your concentrating on making lil'bug-holes, annoyances like this are a PITB.
My way of seeing this is ''If you expect to shoot precision, your gear needs to operate with precision too."

Well...Harry and I have been doing our 'Backyard Engineering' and have come up with replacing those black plastic washers with a set of 8mm bearings...here are the sets where I'll replace the plastic...



These bearing sets are 5mm thick so they took up enough space that I had to install the nylock 8mm nut backwards. It is staying put OK but I have another set of 'roller' type bearings coming in January that are only 4mm thick. That may get me the room to replace that nut correctly.
Here's a little better view...






Before putting it back together I spent some time with some 400 grit wet/dry paper smoothing all the surfaces that rub against each other. I found a place where they didn't grind off all the casting that oozes out in their mould process and that was interfering also...a file took care of this...



Here it is re-assembled and the difference from before & after is like night & day! It is smooth & positive and the thread-lash-slack is gone. When you adjust the wind-age now it feels like a precision assembly.



Harry and I have another revision planned if we can cut that collar, the long tube between the knob and the bearing set on the right...if we can take about 1/2" off it's length it will give me enough space to install a 'wave type' spring washer so that I can have spring tension on the assembly instead of relying on the tightness of the nylock nut.
It'll be January before anything happens with that.

[mdatlanta]

Nice fix! This is an interesting thread.

[Hannibal]

I used to shoot my .22lr out to 300 yards. Never worried about a barrel tuner. Standard velocity 40 grain Federal in the blue box. You need a round where the velocity is very consistent and not every rifle likes the same load. 6" steel. Could ring it 10 out of 10 times usually. Once I figured out the drop it was actually rather boring. The big challenge was the wind. If it was calm or sustained then it was easy, but even a light wind was a problem if it was variable.

My big suggestion would be wind flags if you aren't using them already.

22lr can be extremely frustrating chasing accuracy because you're at the mercy of the ammunition.

Edit to add - something else that I recently learned the hard way. During accuracy testing it's common to shoot a considerable distance from the point of aim. That's all well and good but the further from the point of aim the point of impact is, the more critical scope cant is. Use a target with long vertical and horizontal lines and keep the scope crosshairs perfectly aligned with them. The effects of scope cant is magnified when the POA and POI are separated. The bigger the separation the bigger the effect.

[OS OK]

Hannibal...> The big challenge was the wind. If it was calm or sustained then it was easy, but even a light wind was a problem if it was variable.

I certainly agree with you there & agree with using wind flags, I use several and at strategic locations between the bench & backstop.
I shoot on a ridge and the velocity of the wind can get really strong but it's the direction that throws a kink in the wind solution for each shot...
On the 100 yard range the first 50 yards from the bench is relatively open to the full value wind of the normal direction of wind.
It is that second 50 yards to the target where the wind is molested by that thick treeline, from that gate in the center of the photo going to the right up to the backstop.



On this range, it is that combination of wind effects that ultimately determine where the round is going to print on the target. That's a tough call.
I use several wind ribbons evenly spaced about 25 yards apart but the most important of the wind flags is the wind vane I place at the midpoint in this range...



The vane type wind flag gives me the exact direction and velocity there at the midpoint of the range. It is this indicator that gives me the directional offset in my POA. If I had only one wind indicator, it would be this one here...



Another indicator I use at the bench is the wind meter, this one stays on for the entire bench session...it gives me the 'current' wind speed at the bench and it gives me the 'high' wind speed & the 'average' wind speed. This information changes by the minute and it is a great indicator of the 'general conditions' in each session.



Hannibal...> Edit to add - something else that I recently learned the hard way. During accuracy testing it's common to shoot a considerable distance from the point of aim. That's all well and good but the further from the point of aim the point of impact is, the more critical scope cant is. Use a target with long vertical and horizontal lines and keep the scope crosshairs perfectly aligned with them. The effects of scope cant is magnified when the POA and POI are separated. The bigger the separation the bigger the effect.

I've done all I can to alleviate 'cant' of the rifle. This being 'Bench Rest' shooting that front rest & the way it mates with the fore-foot of the stock eliminates cant...that is, so long as the rest is level. That part is covered from the concrete pad up to the bench...everything is level.



Thanks for your helpful comments Hannibal...I hope you stick with us through spring, I think that about late spring of 23 I will have this rig shooting an average of .400" or less for 5 each of 5 shot groups. That's part of my goal.
The other part is hitting what I am aiming at...



This is the simple target I plan to use. 3/4" stick-on spots, 2 rows of 5 spots with warmers above top left.
Hitting what I'm aiming at means to keep all 5 shots in each group 'on the green spot'...anything off spot means a 'fail'.
The green monster target I am currently using is for getting my testing done, I have a stack of those and they are quick and simple.

[OS OK]

I got out on Christmas day and shot a test card...I wanted to look at the tuner set at .040" down through .036".

Hannibal...Had me thinking about 'rifle cant' so I took the level to the bench to make dang sure about that!



It was what I call a Wind = 0 mph day, what I mean by that is that the wind meter didn't record any current, average or maximum numbers because it will not record wind less than about 1.2 mph. ( It's a cheap wind meter I got off Amazon, $38 ... but it is worth every penny to me. )



But...and there's always a 'butt' in there, but I could feel a varying slight breeze on the back of my neck. It was coming from 5 through 7:00, basically a 1/4'ing tailwind that was just tickling the wind flags.
These slight breezes do have an effect on your round as indicated below on the chart.



Again my purpose was to look at various settings on the tuner with 3 shot groups but not compensating in any way for the wind or trying to tune the scope in to a '0-wind 100 yard zero'...I let them loose and am only concerned with group sizes per setting and their averages.
If there's any promising settings, I would go back and shoot some 5 shot groups to make the testing a little more realistic. When I do find what I think is the tune for this new lot of Eley Match I will increase group size again and re-test...



I know that you all have heard folks saying that 3 shot groups are meaningless when you are claiming some 'MOA status' of your rifle & ammo.
I think that this target will show this clearly when you look at the 3 shot average group size and look at the 5 shot group size...this is what they are trying to explain.

For example I took a closer look at tuner settings .037" & .036" with 5 shot groups.
Look at the increase in group size.

Tuner @ .037" (3 shot group) average size is .456" ... (5 shot group) average size is .709" ... net increase is .253"

Tuner @ .036" (3 shot group) average size is .422" ... (5 shot group) average size is .791" ... net increase is .369"

I can re-test over & over again with the same settings & get a slight varying net increase of the averages going from 3 to 5 shot groups...each test is affected by the conditions of the particular day they were tested & that has a bearing, also the shooter has a bearing on the results no matter how skillful he thinks he is.
That's my opinion about that unless one of you fellas have something to add.

Remember this thread is a 'discussion of discovery' as we progress so don't be afraid to put your 2¢ in.
charlie

[dverna]

Charlie,

This year I did some 10 shot group testing. I saw how much the 5 shot groups were “Fooling” me. Guys shooting three shot groups are deluding themselves.

50 years ago, I was blessed to have a mentor, when I was competing In Bullseye shooting, who had a Ransom rest. He was adamant about shooting 50 shot groups at 50 yards. I thought he was nuts...but he was no fool.

BTW, I have many questions about folks who shoot two shot groups to dial in tuners. Supposedly it works...but I cannot figure out how.

[OS OK]

Charlie,

This year I did some 10 shot group testing. I saw how much the 5 shot groups were “Fooling” me. Guys shooting three shot groups are deluding themselves.

50 years ago, I was blessed to have a mentor, when I was competing In Bullseye shooting, who had a Ransom rest. He was adamant about shooting 50 shot groups at 50 yards. I thought he was nuts...but he was no fool.

BTW, I have many questions about folks who shoot two shot groups to dial in tuners. Supposedly it works...but I cannot figure out how.

Don...Here's a bit of a 'thumb-nail' explanation, the two shot tuner testing is but a search in discovery...for...two shot groups that show the least amount of vertical displacement. But...they can deceive you because without using a chrono at the same time & recording the speed of each shot in each 2 shot group, you will not know whether or not the faster round is hitting lower...meaning...that you are actually shooting and having the round leave the barrel muzzle on the upswing of the barrel. That's what they call 'positive compensation' or some fancy 50¢ word.
Allowing the slower round and it's longer barrel time to leave the muzzle on a little higher muzzle angle.
The slower round arc's a tad-bit higher and drops back near or on the POI of the faster round. But...that's just the beginning because a quality tuner with .001" increment adjustments in barrel length may have 3 sets of adjoining two shot groups that appear close in their vertical displacement...now you have to increase the shot number within the test groups to determine the actual node. Many times those two shot groups have one POI & that helps to find the node much faster but that one hole can be an anomaly...wind can muddy the results pretty quickly.
Sounds complicated but it's not really...but...sometimes it takes many rounds of expensive ammo to find that magic node.
Determination and recording good empirical data is what educates the shooter quickly in future node searches.

[OS OK]

Charlie,

BTW, I have many questions about folks who shoot two shot groups to dial in tuners. Supposedly it works...but I cannot figure out how.

Don...here's an example of a node search on Eley Match, (when I order Match I always buy it rated for 1055 fps) this time they were out of those lots.
Still...the node search won't be far off the 1055 fps node I have for the previous order. I don't need a chronograph here to plot individual POI's, that work has been done earlier in the year. My last lot was rated @ 1055 fps and averages 1080 fps in my barrel/chamber. This new lot is very close.
I don't know Eley's procedure in rating their lots but something I've noticed is...for the half dozen lots I've bought in the last 2 years rated at 1055 fps, their average fps does change by a few fps in my rifle from lot to lot & their ES & SD's change also.

2-shot search for 'minimal vertical dispersion'...(remember to consider the wind, these are not as accurate as they could be indoors)



A few days later I decide to look at 5-shot groups for settings .036" ~ .032" ...



The tuner work above is done at 50 yards. I chose the .034" tuner setting to move over to the 100 yard range and see how it does? (this is before I was made aware of having to re-tune for the longer range)...



This is unusual in that I normally will shoot an entire card in one stretch...for some reason I don't recall, I stopped at target 6 for 25 minutes.
When I resumed, I shot 5 warmers on the 'B' spot and then went to spots 7 & 8. The groups opened...I think this is where I started to think that the lube had changed in the barrel in that 25 minutes.
Maybe it becomes 'crusty' or 'dryer'...I don't know or whether the little bit of warmth in the bore bled off and I have a 'cold bore barrel' when I started again, I don't know?
That's something I am still mulling over?