What type of barrel rifling is this?

[Mr. Wolf]

Relatively new to rimfire and very new to CZ 457 aftermarket barrels.

This Lothar-Walther aftermarket barrel shoots better than my stock 16", no keyholes.
To prep for an upcoming match, I was going to cleaning my chamber and look for carbon ring, so I popped in my newly acquired bore scope.
To my surprise, it was hard to find any rifling, at least compared to the CZ, Ruger, and Kidd barrels.

For the more experienced, what am I looking at? Is this polygonal rifling, a manufacturer defect, or are the rifling worn out/damaged?
I've done very minimal cleaning initially, no copper or steel brush, just nylon brush and a few patches with Boretech Rimfire Blend down the barrel with an .17" Tipton rod and plastic eyelet.

Thank you for your advice and help in advance.

Photo 1. Carbon ring and leade
Photo 2. Best shot of the rifling I could get
Photo 3. Crown

 

[BuildingConceptsllc]

Isn't that right by the chamber ? What does it look like further down the barrel? Also make sure you aren't just in between the grooves

 

[Mr. Wolf]

1st photo chamber/leade
2nd and 3rd photos best shot of the rifling I could get on the Tesslong bore scope.

 

[KZP]

Try looking with the borescope right over the muzzle crown. Should be able to get a better perspective of depth with what's going on.

 

[Shoots 700's]

Keep shooting it if it shoots so well

 

[Near miss]

My friend's tikka T3X has gotten bad pitting near and right at crown but it still shoots great.

 

[prebancolt]

Not related to the rifling, but to the picture quality. Does your borescope have a mirror on the end that screws on and up to a set screw? Try adjusting the mirror further on or off and you can adjust the focus point to bring the chamber and riflings into clearer focus. I just bought the Teslong borescope and had to adjust mine like this. It works great now and produces very clear images.

J

 

[BisSilent]

It is polygonal rifling! My Lothar Walther barrel looks the same and is a hammer. You just need to use a bronze brush and clean the carbon ring.

 

[grauhanen]

The focus of the image may improve by adjusting the distance between the tip and the mirror, which can screw in and out and be locked in place.

 

[Mr. Wolf]

Thank you for the responses, keep 'em coming. I don't think it's a focus issue as the lands/grooves are clear on my other 22LR barrels.
Photo 1: Axial view of the Lothar Walther CZ 457 replacement barrel
Photo 2: I think I see 6 smooth "hills" at the bullet seating/leade... possibly polygonal rifling like BisSilent wrote?
Photos 3 & 4: My Kidd 10/22 barrel (also Lothar Walther) but with traditional rifling and clearly visible leade. (another excellent shooter)

I think BisSilent may be onto something with the polygonal barrel, as Lothar Walther is one of the world's largest manufacturer of barrels. It's just that it's common in pistols, some air rifles, and rarely on center fire rifles (mostly European barrels), but it's the first I've encountered on a 22LR rimfire rifle.

It's definitely a shooter with consistent sub 1 MOA groups out to 100 yards (ref JBell's 6x5 @ 100 yds post).
Are you aware of any other 22LR polygonal barrels?

 

[BisSilent]

It's a 6 groove polygonal barrel!!! You don't accidentally shoot sub moa at 100 with a worn out barrel

 

[Huskydriver]

It's poly rifling.....


Rimfire is gayier than aides unless you are 9...

That is all

 

[Shoots 700's]

Again, quit looking at the bore and shoot it.

 

[Mr. Wolf]

It's a 6 groove polygonal barrel!!! You don't accidentally shoot sub moa at 100 with a worn out barrelView attachment 7952907

their website shows that they don’t do custom ordered polygonal barrels in 22LR.

 

[BisSilent]

their website shows that they don’t do custom ordered polygonal barrels in 22LR.
View attachment 7953240

But they do, cuz I have one!! They also don't show other twist than 1:16.5 and mine is 1:12 You have to ask for it!!!

 

[obx22]

Thank you for the responses, keep 'em coming. I don't think it's a focus issue as the lands/grooves are clear on my other 22LR barrels.
Photo 1: Axial view of the Lothar Walther CZ 457 replacement barrel
Photo 2: I think I see 6 smooth "hills" at the bullet seating/leade... possibly polygonal rifling like BisSilent wrote?
Photos 3 & 4: My Kidd 10/22 barrel (also Lothar Walther) but with traditional rifling and clearly visible leade. (another excellent shooter)

I think BisSilent may be onto something with the polygonal barrel, as Lothar Walther is one of the world's largest manufacturer of barrels. It's just that it's common in pistols, some air rifles, and rarely on center fire rifles (mostly European barrels), but it's the first I've encountered on a 22LR rimfire rifle.

It's definitely a shooter with consistent sub 1 MOA groups out to 100 yards (ref JBell's 6x5 @ 100 yds post).
Are you aware of any other 22LR polygonal barrels?
View attachment 7952902View attachment 7952903View attachment 7952904View attachment 7952905

Heckler & Koch offered polygon rifling in their models 300 (.22Mag) and 270 (.22LR).
Glock barrels are supposed to be polygon, but remind me more of the rifling shape in Remington’s 5-R (sloping walls to the lands). I don’t know if that rifling type extends to the model 44.
My H&K 270 in a great gun, perhaps the most accurate factory autoloader rimfire I’ve fired.

 

[RTH1800]

Again, quit looking at the bore and shoot it.

Though I agree that looking at the bore might not serve much purpose other than to satisfy curiosity, I find it interesting that those who chose ignorance over information are always adamant that others do the same.

No one can fire a rifle constantly nor would most care to. So, we examine, check torque specs, change out scopes and mounts, examine groups and yes, look in the bore occasionally. It’s all quite harmless and occasionally enlightening.

 

[Mr. Wolf]

Thank you very much for the responses. Helpful to learn more about this type of barrel in rimfire rifles.
What it looked like in the bore scope never stopped me from shooting.

I have noticed that after approx 300 rounds, cleaning it brings the 5 shot group accuracy back to the .2s and .3s at 50 yds. Clean up is rather simple and easier than the traditional land and groove rifled barrels, but i’ve noticed a tight spots in the middle when running a patch through.

I took it to the range today and shooting prone with a bipod and rear bags, KYL at 75 yds down to 1/2” was 5 for 5. Hit 9 of 10 on a 1” steel target at 150 yds, 4x7” steel plate at 200 is a gimme. It seems to be more accurate further out.

YMMV, happy shooting.

 

[grauhanen]

their website shows that they don’t do custom ordered polygonal barrels in 22LR.

This is true of the website, which indicates bores in .22LR are not available in polygonal rifling.

The reference above in post #11 appears to be with regard to .224 caliber barrels, which are not the same as .22LR.

But they do, cuz I have one!! They also don't show other twist than 1:16.5 and mine is 1:12 You have to ask for it!!!

For what it's worth, I sent Lothar Walther sales an email very recently, asking "Does Lothar Walther make .22LR polygonal barrels?"

I also asked "If they are available, are they in 1:12 twist as well as standard?"

I received the following reply:
Unfortunately, we are not able to make .22LR polygonal barrels. We are only able to offer them in the standard rifling. We only offer these with the 1:16” Twist.

I can only make the observation that if Lothar Walther makes polygonal .22LR barrels, they would appear to answer at least some email questions about them in the negative.

The reply came with the customary advisory about the content of the email.

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[BisSilent]

I will leave you with this. The opp has a polygonal rifled 22lr, my friend and I both have the same polygonal rifled Rim-X 1:12 barrel.

The .224 barrel works for alot of cartridges as shown below. I just got lucky it works for 22lr too!!

 

[gonzaga]

Why waist so much range time looking at the barrel?
When problems arise, that's when you look at the barrel and the loss of accuracy.
That's why they make replacement barrells.
Go shoot it.
Show us some groups...

 

[BisSilent]

Why waist so much range time looking at the barrel?
When problems arise, that's when you look at the barrel and the loss of accuracy.
That's why they make replacement barrells.
Go shoot it.
Show us some groups...

100 yard 6x5 worn out LW polygonal barrel

50 yard 6x5

 

[gonzaga]

Nicely done ^^^^

 

[jstiller]

Shilen makes one. They call it their octagon. It has an interesting looking rifling pattern. Some shoot very good.

 

[Drknite]

Pacnor also makes one. At least they did a few years ago.

 

[340mech]

The British used it 135 years ago.

 

[Mr. Wolf]

100 yd 6x5 target
.771“ avg, all under 1”
barrel fouls quickly, I clean every 200 rounds