New 22 rifle - Searching the accuracy

[Jayjay1]

Hi all,

I have a CZ455 with a 22" Lothar Walther bull barrel and a Meopta 5-30x56 on top of it.

I wasn´t really satisfied, so I tried it prone and from the bench, with bipod and a sand bag at the front.
I´ve tried 10 different ammos today, best group was 2.5" at 100 meters.

To find a solution I´ve measured the velocities, because I thought maybe I´m breaking through the speed of sound backwards and the bullets may tumble a bit.
Some were under, some at and some over the s-o-s at V0, couldn´t find a context.

I´ve noticed also, that the barrel seems to be full of powder or parts of the bullets, I barely could see light through it.
Is this normal?

Can it be, that I just didn´t find the right ammo yet?

Any thoughts or recommandations are welcome,
cheers,
Jay

 

[ma smith]

did you clean it?

 

[Jayjay1]

You mean before I began to shoot?

I pulled a boresnake through.
Have ordered a cleaning rod for the .22, it is on delay since weeks.

 

[Defender32]

What was your ammo of choice??

I would pull a snake through it a few times with some sort of cleaner on it. CLP, Balistol, Boretech Rimfire blend.

 

[Jayjay1]

Geco Rifle
Federal
Blazer
RWS Rifle Match S
RWS Target Rifle
RWS Club
SK Rifle Match
Winchester Super X
CCI Mini-Mag
CCI SV
Magtech
all 40gr.

 

[jbell]

Geco Rifle
Federal
Blazer
RWS Rifle Match S
RWS Target Rifle
RWS Club
SK Rifle Match
Winchester Super X
CCI Mini-Mag
CCI SV
Magtech
all 40gr.

After you clean the bore properly stop wasting your time and money with that ammo and get some true quality ammo. Right now your limiting factor is ammo.

 

[Jayjay1]

Well, so what is high quality ammo?

 

[jbell]

Eley Tenex, Eley match, Lapua Midas, Lapua Xact, Lapua CenterX
Start with those and find the lot your rifle likes. Feel free to PM me if you have any specific questions about lot testing, I am happy to help in any way I can.

 

[dash4cash]

Lapua Center X, Lapua Midas, Eley Tenex, Eley Match

 

[Jayjay1]

Thanks guys, I appreciate your help.

Will have to look where I can get that ammo though.

 

[b6graham]

switching ammo types back to back probably doesnt help much either

 

[jbell]

switching ammo types back to back probably doesnt help much either

Exactly
People will tell you to clean between ammo brand, but personally I think it's not necessary. If your barrel is seasoned to one brand say Lapua and switch to Eley you can expect the first 5-6 rounds to produce a screamer group. Ignore it! Round 7-15 maybe up to 20 will go to shit and start to settle in. After that you can start to assess what the ammo will do in your barrel. This is a generalization but you will find it's going to be within 2-3 rounds correct.

Switching between Eley Tenex and Eley Match there will be no change. Same goes for or Lapua Center X, Midas, or Xact.

 

[Jayjay1]

Well, that declares something.
I made 5 shot groups of each ammo type and then I repeated it with 10 shot groups, but it didn´t help much.

I think I have to start over again.

Thank you again.


Will staying subsonic help?
I´m shooting 99% of the time at 100 meters.

 

[b6graham]

Exactly
People will tell you to clean between ammo brand, but personally I think it's not necessary. If your barrel is seasoned to one brand say Lapua and switch to Eley you can expect the first 5-6 rounds to produce a screamer group. Ignore it! Round 7-15 maybe up to 20 will go to shit and start to settle in. After that you can start to assess what the ammo will do in your barrel. This is a generalization but you will find it's going to be within 2-3 rounds correct.

Switching between Eley Tenex and Eley Match there will be no change. Same goes for or Lapua Center X, Midas, or Xact.

yup

biggest mistake people make is doing 5 or 10 shot groups and just switch ammo and repeat over and over without reseasoning the barrel

 

[jbell]

Well, that declares something.
I made 5 shot groups of each ammo type and then I repeated it with 10 shot groups, but it didn´t help much.

I think I have to start over again.

Oh yeah that's definitely not the move. If you still have that ammo listed on hand try it again for sure! Basically expect 15-20 rounds to properly season a bore. Pay very close attention to wind! Wind flags are very helpful even if they are something you make. Just 1-2 mph full value is 1/4 of a bullet hole at 50 yards.

 

[jbell]

And use several wind flags not just one at the firing position or one at the target.

 

[huntnh]

Are you using any sort of muzzle brake or suppressor? If yes take it off and try it

 

[Appalachian]

My CZ’s shoot SK Rifle Match pretty well, not as good as Center X, but close. I would start with a clean barrel and shoot 10 Five shot groups of the SK. Wait for a calm day and or use wind flags. Average the last 6 Five shot groups and report back.

 

[Jayjay1]

Are you using any sort of muzzle brake or suppressor? If yes take it off and try it

No, I use nothing like that.

 

[Jayjay1]

My CZ’s shoot SK Rifle Match pretty well, not as good as Center X, but close. I would start with a clean barrel and shoot 10 Five shot groups of the SK. Wait for a calm day and or use wind flags. Average the last 6 Five shot groups and report back.

As I wrote, 22" Lothar Walther bull barrel.

 

[Jayjay1]

At 100 meters:
Should I use subsonic or not?

I´m thinking if I use ammo which is slightly above the speed of sound, it will go through the sound barrier on a 100.

 

[Badshot308]

At 100 meters:
Should I use subsonic or not?

I´m thinking if I use ammo which is slightly above the speed of sound, it will go through the sound barrier on a 100.

It'll drop below before it reaches 100. 22's are picky about what ammo they shoot best. You could try sending it to either Lapua or Eley testing centers to see what type and lot it shoots best, or keep testing what you have locally available. Listen to jbell's advise. When switching between different brands, you need to shoot enough rounds to season the bore with that particular brands bullet lube before you'll get consistent results.

 

[Badshot308]

It'll most likely drop below before it reaches 100. 22's are picky about what ammo they shoot best. You could try sending it to either Lapua or Eley testing centers to see what type and lot it shoots best, or keep testing what you have locally available. Listen to jbell's advise. When switching between different brands, you need to shoot enough rounds to season the bore with that particular brands bullet lube before you'll get consistent results.

 

[Jayjay1]

It'll drop below before it reaches 100.

Yes, that´s the reason for my question.

It will go through the sound barrier backwards and get a shock wave.
This should affect accuracy, or not?

 

[Badshot308]

Yes, that´s the reason for my question.

It will go through the sound barrier backwards and get a shock wave.
This should affect accuracy, or not?

It doesn't go through the sound barrier backwards. Most match grade ammo is going to be subsonic with a couple of exceptions such as RWS R100 and SK Long Range Match. Both those rounds are just barely above the speed of sound at the muzzle and below it before they reach 100 meters. Both loads are designed for 100 meter competition.

 

[Appalachian]

As I wrote, 22" Lothar Walther bull barrel.

Still. SK Rifle Match is the best out of what you have and I know of one LW barreled CZ that likes it.

 

[justin amateur]

New CZ 455 eh? Which model?

Varmint? American? Precision Trainer? Stainless with Tupperware stock?

Bullet speed is not y'er problem.
The Aberdeen Ballistics Laboratory found insignificant difference in accuracy
between supersonic and subsonic high quality 40 grain 22lr.

Quality is where the problem arises.
Cheap hi-v 22lr is not precision ammunition.

All you have to do is look at those cartridges to see the problems.
They're already beat to snot fresh from the factory.
Dents, dings, scratches, chips, sloppy crimps, uneven drive bands.
Crappy ammo produces crappy results.

The reason hi-v 22lr produces such poor results is because it's low quality ammunition.
Not because it transitions from super to sub sonic at 30 to 40 yards from the muzzle.

Torque specs for the CZ 455...
Stock to receiver not to exceed 24 inch-lbs
Barrel set screws 30 to 34 inch-lbs
Magwell screws, tighten to contact then 1/8th turn more.

Factory CZ 455 stocks, except for the Precision Trainer, show some serious flex.
Slim lines and large amount of inletting being the cause.
Support the rifle just forward of the magwell, not out at the forend.
It'll minimize the springboard effect and tighten up those trajectories.

Hand chamber every cartridge when shooting for precision.
The CZ mags don't always seat in alignment with the chamber.
It can result in damage to the drive bands when the bolt picks up a cartridge and jams it into the chamber.

Pillar and bed the receiver.
Bed the barrel just forward of the receiver.

Try and find actual competition quality ammunition.
Just because it has the word "Match" on the label, doesn't make it so.

 

[jbell]

At 100 meters:
Should I use subsonic or not?

I´m thinking if I use ammo which is slightly above the speed of sound, it will go through the sound barrier on a 100.

I have found with testing a lot of custom rifles and a lot of ammo over the years that the ammo I listed will net the best results in most every rifle. I have very rarely found RWS R-50 or R-100 hang with those I listed. That said for some reason Eley Tenex is usually the fastest of the bunch, rarely do you find a lot of Tenex that is below 1060fps. I have never seen any high velocity ammo shoot anywhere close to subsonic match ammo.

With all that said, just test proven match ammo based on down range results not FPS. Record the FPS of the ammo you test if you have a reliable method of measuring it or simply record what the manufacturers list that specific lot as (but keep in mind the actual may be slightly different in your barrel) to use as a reference when making your next purchase or changing brands as a starting point.

 

[BuckeyePrecision]

You say new, but is it new or new to you? If it is new to you and the barrel has had a lot of rounds through it, it could have developed a carbon ring which can play hell with accuracy.

That RWS Rifle Match S is probably your best bet for a good group. If you have enough of it left, do as the others have said. Clean the barrel with a good carbon/lead cleaner (if you get your real cleaning kit first, pay close attention to the carbon ring just forward of the chamber). Use only that ammo. Dont be surprised if the first few groups are not great, once the barrel is nicely fouled with that ammo you may see some decent groups. My Tikka with a Lilja on it and my buddies Vudoo are both shooting about 1 in. @100 with that stuff.

 

[SirDrinksAlot]

I've also had really good luck with Lapua OSP in my Vudoo.

 

[grauhanen]

There's quite a lot of advice offered and the OP's head may be spinning. No doubt he heard that getting a custom barrel would surely improve results. It's one step of several to help get better consistency.

Break down the task into at least two different areas -- first the rifle and second the ammo.

To fully realize the best the barrel can deliver, the rifle should be pillared and bedded, as justin amateur recommends. Get the trigger pull reduced to less than 16 ounces. The CZ 455 trigger pull can be easily made lighter with a spring change. Make sure the bench or table from which you shoot is as solid as possible and that the front rest or bipod is suitable. Make sure to use a consistent hold with the rifle.

Regarding the ammo, the best accuracy will be achieved with standard velocity match ammo. It is usually made to a higher quality standard, with more consistent muzzle velocities. High velocity is invariably less consistent in quality and performance. There are three main match ammo makers -- Eley, SK/Lapua, and RWS. Each one produces several varieties or grades of ammo. Each variety is made in batches called lots. It's important to be aware that ammo performance varies by lot, which is to say not all lots of any given variety -- whether they are SK Rifle Match, Lapua Center X, Eley Match, or Eley Tenex, for example -- will perform equally in your rifle. Some lots will be better than others. Simply buying a few hundred rounds of top dollar Eley Tenex or Lapua Midas + will not guarantee anything in terms of how it will do in your rifle.

Given the difficulty shooters may find in locating .22LR ammo, it may be advisable to find a standard velocity match ammo that is within your budget and buy several lots of it if you can. As an example, if you can find SK Rifle Match, which is often a good practice ammo because of its general quality and price, that's available in several different lots, you may wish to try it. There are other varieties that can perform well and the challenge is to find what's in your budget and available so that you can test it.

Selecting an ammo arbitrarily has a chance of finding an ammo that shoots well in your rifle. But it's a crap shoot.

 

[Gjmen22]

Eley Tenex, Eley match, Lapua Midas, Lapua Xact, Lapua CenterX
Start with those and find the lot your rifle likes. Feel free to PM me if you have any specific questions about lot testing, I am happy to help in any way I can.

All excellent choices. I would also add RWS R-50 to the list. I have had some really good luck with it in some of my rifles.

Gjmen22

 

[Jayjay1]

Holy moly, that are a lot of infos and questions, thank you for that.

I own the CZ 455 quite a while, it was a Thumbhole version with a bull barrel and it shot lights out.
It has a Yodave trigger spring kit and I was really happy with it.
1" at 100m was usual.

Then I decided to clean it seriously and have used the cleaning rod from my 223.
That was not a good idea.
Short from here you will call me an idiot, and I can´t argue that.

The rod stuck shortly after the chamber, so I tried to pull it back.
But it didn´t move a yota backwards because the brush, fully in the barrel, held it back.
I pulled as hard as I can, no chance.
So after cursing and searching a conclusion for a while, I saw no other way as to push it all the way through.
Barrel was clean, but accuracy was gone.

I couldn´t get a bull barrel anywhere, so I got me the normal thin barrel with iron sights.
But I was dissapointed because of its accuracy as well.
After a while I decided to "do it right".

Ordered the LW BB 22" barrel and a Boyds Pro Varmint stock.
The Thumbhole stock was fine, but only one sided and I wanted an ambidextrious stock, because my daughter is a lefty.
It was a bit short as well, the LOP was to short.
The system is glas bedded by me, including the first 1.5" of the barrel.
Torque specs are held like recommended from CZ, barrel and system.
The barrel is free in the stock.
I´m using a Harris bipod at the front and a sand bag at the rear.
I have installed a picatinny on the system, where a Meopta Optika6 5-30x56 sits on top.
Actually I thought this might make a quite good combo though.

I will have to read again what you all wrote.
Then I will try to get some of your recommended ammo and start it over again.


P.S.:
So I understood, that it doesn´t matter when the bullet goes backwards through the sound barrier.
Different from what I´ve learned with centerfire rifles, but you share your wisdom with me and I´m happy to take it.
Like my old shooting buddy used to say:
"Only the target tells the truth."

 

[jbell]

Like my old shooting buddy used to say:
"Only the target tells the truth."

Exactly

 

[Radman1]

Hi all,

I have a CZ455 with a 22" Lothar Walther bull barrel and a Meopta 5-30x56 on top of it.

I wasn´t really satisfied, so I tried it prone and from the bench, with bipod and a sand bag at the front.
I´ve tried 10 different ammos today, best group was 2.5" at 100 meters.

To find a solution I´ve measured the velocities, because I thought maybe I´m breaking through the speed of sound backwards and the bullets may tumble a bit.
Some were under, some at and some over the s-o-s at V0, couldn´t find a context.

I´ve noticed also, that the barrel seems to be full of powder or parts of the bullets, I barely could see light through it.
Is this normal?

Can it be, that I just didn´t find the right ammo yet?

Any thoughts or recommandations are welcome,
cheers,
Jay

Your best group 2.5" @ 100 meters, do you know which of the 10 brands gave you that group, just curious.

 

[Jayjay1]

Your best group 2.5" @ 100 meters, do you know which of the 10 brands gave you that group, just curious.

Well, some of them were around that.

I would say Geco, Federal and SK Rifle Match were on par or very close.
One of the HV, CCI MiniMag, wasn´t "bad" either.

 

[Jayjay1]

Just checked the freefloat of the barrel again, my wife had to pull a paper through while I was prone, everything fine.

Then I pulled the system and barrel out.
It was a blink of an eye, but I just thought the front system screw was lose, I´m not sure.
My bad I didn´t expect that a screw could be lose, so I just pulled them out.
But so I have something to look at.
I wouldn´t be unhappy if that was the problem either.

Will losen and refit barrel and system.
Then watchout for the ammo and hope I can shoot next week.

Thanks guys.

 

[grauhanen]

I´ve tried 10 different ammos today, best group was 2.5" at 100 meters.

Test at 50 to help reduce the errors that get magnified at distance. It can often be hard to tell whether it's the ammo, the rifle, the wind, or shooter inconsistency, or a combination of some or all of these, that explains results at 100 meters.

With regard to ammo, muzzle velocity (MV) variation alone can cause large groups at 100 meters. No one knows the MV of an individual round unless it's chronographed. The velocity published on the box or on a chart is the nominal MV, not the actual MV. MV can vary a great deal from one round to the next, especially in less expensive ammo varieties. The difference between the fastest and slowest rounds is the extreme spread (ES). A good batch of expensive ammo like Tenex or Midas + can have an ES of 30 fps, a typical batch of CCI SV can easily double that. Each 10 fps difference between rounds of SV ammo produces about .25" of vertical. Two rounds of CCI SV that have a 30 fps difference in MV will be separated by about .75" of vertical -- and that's with perfect shot execution in a perfectly shooting rifle.

To illustrate the wind problem, a difference of 1 mph of crosswind between shots with CCI SV results in over .5" of drift. With CCI Mini-Mag or other high velocity .22LR ammo it's even more. A 1 mph change in wind speed is barely noticeable, if at all. When the wind varies between shots it can play havoc on group sizes, even with perfect shot execution in a perfectly shooting rifle.

Shooting at 50 yards or meters doesn't eliminate these factors, but it reduces them significantly. At 50 yards a 10 fps difference between rounds is almost negligible. At 50, each 1 mph crosswind produces less than a third of the drift that occurs at 100. Shooting at 50 rather than 100 helps permit evaluation to focus more on shooter and ammo performance, especially for newer shooters. Of course, poorly shooting ammo still won't group well.

Below is a ballistics chart showing the wind drift for CCI SV and CCI Mini-Mag with a 1 mph crosswind.



Below is a ballistics chart showing the amount of vertical drop between two CCI SV rounds with a 10 fps difference in muzzle velocity.

 

[Booner1334]

Holy moly, that are a lot of infos and questions, thank you for that.

I own the CZ 455 quite a while, it was a Thumbhole version with a bull barrel and it shot lights out.
It has a Yodave trigger spring kit and I was really happy with it.
1" at 100m was usual.

Then I decided to clean it seriously and have used the cleaning rod from my 223.
That was not a good idea.
Short from here you will call me an idiot, and I can´t argue that.

The rod stuck shortly after the chamber, so I tried to pull it back.
But it didn´t move a yota backwards because the brush, fully in the barrel, held it back.
I pulled as hard as I can, no chance.
So after cursing and searching a conclusion for a while, I saw no other way as to push it all the way through.
Barrel was clean, but accuracy was gone.

I couldn´t get a bull barrel anywhere, so I got me the normal thin barrel with iron sights.
But I was dissapointed because of its accuracy as well.
After a while I decided to "do it right".

Ordered the LW BB 22" barrel and a Boyds Pro Varmint stock.
The Thumbhole stock was fine, but only one sided and I wanted an ambidextrious stock, because my daughter is a lefty.
It was a bit short as well, the LOP was to short.
The system is glas bedded by me, including the first 1.5" of the barrel.
Torque specs are held like recommended from CZ, barrel and system.
The barrel is free in the stock.
I´m using a Harris bipod at the front and a sand bag at the rear.
I have installed a picatinny on the system, where a Meopta Optika6 5-30x56 sits on top.
Actually I thought this might make a quite good combo though.

I will have to read again what you all wrote.
Then I will try to get some of your recommended ammo and start it over again.


P.S.:
So I understood, that it doesn´t matter when the bullet goes backwards through the sound barrier.
Different from what I´ve learned with centerfire rifles, but you share your wisdom with me and I´m happy to take it.
Like my old shooting buddy used to say:
"Only the target tells the truth."

Get yourself a cleaning rod for a .20 caliber rifle. It will fit the bore of your .22rf better, ie a little looser. You'll have to get an adaptor for the tip of the cleaning rod so your .22 bore brushes and jags will fit it though.
I assume your bore brush was new and that's why it wouldn't change directions in the barrel. I don't like to use a wire brush in my .22's, I use a nylon brush. The brisells are soft enough so that you can "scrub" a spot in the barrel if you need to and it won't look in the barrel. Once a wire brush is older and partly worn out you can change directions in the barrel but it's not recommend.

What did you do with the bull barrel?

 

[Jayjay1]

What did you do with the bull barrel?

Brought it to a gunsmith to destroy it.

 

[Njpddet]

I find this all fascinating. I’m new to rimfire and sighted in my new Anschutz 1761. Then I tried shooting some different ammos back to back. I shot in order, Eley Club, RWS50, Eley Tenx, Lapua Polar. The wind was pretty strong so I’m sure that I can do better in better conditions but I had no idea there was a process to testing and evaluating different ammos. I guess that I’ll have to read up on the how to’s and start all over again. Oh well, more range time.

 

[Jayjay1]

Well, with a centerfire rifle you do load developement because not any ammo will shoot the same best groups out of any rifle, right?

Why should this be different with a rimfire rifle?

 

[jbell]

It's not, that's why you test all brands and lot numbers you can.

 

[justin amateur]

...test all the brands and lot numbers...

And when you do find a batch that does well,
after you've used it all up, you have to do it all over again.
Because it's unlikely the next batch you purchase will produce the same results,
not even from the same manufacturer and the same assembly line at the same factory.
That's the fun of rimfire ammunition. Cartridge quality changes moment by monent
as it's assembled on the production line.

 

[jbell]

That's the fun of rimfire ammunition.

exactly

 

[grauhanen]

And when you do find a batch that does well,
after you've used it all up, you have to do it all over again.
Because it's unlikely the next batch you purchase will produce the same results,
not even from the same manufacturer and the same assembly line at the same factory.
That's the fun of rimfire ammunition. Cartridge quality changes moment by monent
as it's assembled on the production line.

When the Eley Lot Analyzer was available, it showed that not all lots of ammo performed equally in the four Eley test barrels. This clearly demonstrated that two or more good rifles may shoot the same ammo differently, that ammo might be good in one rifle, but not in every one.

If two very good rifles can shoot the same lot of ammo differently enough that one shoots it better than the other, changes in cartridge quality isn't always or necessarily the issue. When ammo quality isn't the problem, what causes one rifle to shoot a lot of ammo better than another?

 

[justin amateur]

I don't think it was differences in the rifles causing the different results G.
I'm thinking the variations are due to tolerance stacking in the components and assembly.
No two cartridges are exactly alike and with the number of variables involved in the manufacture
it's unlikely that cartridges from the same run will produce consistent trajectories, not even from the same box.
I don't place the blame on the rifles, but on cartridge defects.
You can't fire the same cartridge twice in two different rifles.
That is why the results vary, it's the small variations in cartridge quality that are responsible.

 

[Slides]

That discounts chamber and bore variation between two good rifles being slightly more or less compatible with a particular batch.

 

[justin amateur]

I'm no ballistics technician, shooting from a fixture in a tunnel,
however I do have a hard drive full of target results and chronograph numbers.
I noticed a pattern from reviewing all that information, if you give me well made rimfire cartridges
with tight muzzle velocities, it didn't matter which rifle it was shot from, results were excellent.
Yes, the point of impact might be different from rifle to rifle, but the trajectories were all tight.
That's why scopes have turrets to adjust the crosshairs.
It wasn't a preference by rifle that made the difference in results, just cartridge quality.
There is no find the brand y'er rimfire rifle likes, only finding well made cartridges with tight mv's.
No rifle can make low quality cartridges produce consistently accurate results.

 

[grauhanen]

For those unfamiliar with the Eley Lot Analyzer, for a time Eley made available online the test results of each lot of match ammo they produced. A lot number was plugged into the Lot Analyzer and information, including images like those shown below, were available to the user.

Below are the Eley testing results for four different lots of Tenex. Each image has five ten shot groups shot from four different barrels in Eley test tunnels.

Note that some barrels showed better or worse results with the same lot of ammo.
(Continued below.)





One premise is that ammo quality alone explains the variation, that individual rounds are better or worse in terms of their individual quality, with fewer or more defects, with components more or less close to tolerances.

Another premise is the one noted above by Slides regarding chamber and bore variation between two good rifles with the result that some bores are, as Slides put it, "slightly more or less compatible with a particular batch."

If the first premise is correct, this means that all good rifles shoot the same good ammo similarly and that any variation between results is attributable to the individual rounds only. Any difference between the bores of good rifles is irrelevant. All good ammo is good ammo in all good rifles.

More specifically, according to the first premise, any poor or inconsistent results seen in one barrel are arbitrary and could just as easily occur in any or all of the other barrels. The fact that some barrels shot five ten-shot groups (50 consecutive rounds) of one lot very well and another another didn't is just the luck of the draw. The results of the other test barrels shows that this lot of ammo had too many rounds of poor quality.

The second premise holds that the characteristics of individual bores play a significant role in the results on the target. It should be noted that this view doesn't need to imagine there's no variation between rounds within a lot or even within a box. The idea is that barrels/bores can respond differently with different lots of ammo.

To return to the Eley Lot Analyzer, it should be noted that it is no longer online. It appears it was more trouble than it was worth, with some Eley users basing expectations of ammo performance on the Lot Analyzer results. It seems that too often even the lots that performed most consistently in the Eley test barrels didn't reproduce similar consistent results in the shooter's rifle.