A funny story about barrel runout.

[Alex Wheeler]

I thought you guys might get a kick out of this. So, I chamber barrels everyday. Its pretty much 90% of what I do now. I dont know how many barrels I have cut but its a good amount so I feel like I have a good handle on whats in the normal range for bore straightness. I only dial the end I am working on (you will see why). With that method the other end will runout in the lathe. I would say the normal range of tir is about .025" or so. You will see up to .050" sometimes and sometimes its almost zero. I have never seen any correlation to accuracy here. Now I have seen some with real heavy diamond flutes runout around .100" But only a few.
Now to the story. I dial in a blank for a customer and notice the runout is quite bad. I cut the chamber and flip it to crown and its even worse. So I throw and indicator on it and we are running out over .300". Thats 3x worse than anything I have seen. Ok, call the manufacture. No problem. They will replace it. Call the customer. I explain the situation. They will make you a new one, no problem. But its not in stock. He was anxious to get shooting so he decided to try it. Knowing if there was any issue, we'd get him a new barrel. I explained he would have elevation issues. I clock the barrels up, so it would effect elevation, but not windage. Dialing only one end takes that curve out of the picture, so the throat looked just as centered as any other barrel. The curve was very obvious to the eye, it was a consistent curve like a banana for those interested. I told him to keep me in the loop, good or bad. I said, it wouldn't surprise me if it was the best you ever have, it also wouldn't surprise me if it was the worst. Anyhow, I just got this email. It put a smile on my face, I had to laugh.

Howdy Gents,

I thought I'd drop in and give you both an update on my barrel, now that I've had a chance to run a proper powder test and seating depth test on it over the past few weeks. My hat is off to you both - because even with the runout issues you warned me of, this barrel has been the best I've yet to place into my hands.

I'll be frank - the runout was and still is quite noticeable - but the saving grace is that it's almost perfectly oriented in the vertical, and it has the effect of adding about a 10 MOA canted pic rail onto the optic. Once I swapped my previous canted rail for a zero MOA rail, I was able to dial in a very reliable zero at 200 yards (which leaves me about 40 MOA of adjustment) and put the barrel through testing. As shown in the attached image, my best group of the seating test was the smallest three-round group I've ever shot.

I've shot it at a few league matches now and am feeling confident in her ability to group at distance - so with that being said, I think we can call this case closed.

Thank you both for your help, guidance, and patience through this process - this may be my first custom cut barrel, but you both now have a customer for life.

Cheers,

 

[X-Caveman]

Stick Starks told me several years ago that one of the best shootin barrels he ever chambered was so crooked he couldn’t see light thru it. Guess it makes it tough to bore sight.

 

[ogre1911]

If you had indexed it horizontal either one side or the other it could shoot around corners...... lol

 

[Hal]

Alex

Thanks for sharing. I always try to read your posts.
Be interesting if someone had the test equipment and tested the banana against a barrel that was nice and straight.
I wonder if the banana barrel would show less vibration ?

In the end all that matter is how they shoot.

Hal

 

[jackieschmidt]

Great.

 

[JMayo]

Interesting for sure.

 

[DShortt]

Very interesting!
Thanks for sharing. Much appreciated.

 

[TAJ45]

Sounds like a candidate for Ripley's.

 

[hoz53]

I thought you guys might get a kick out of this. So, I chamber barrels everyday. Its pretty much 90% of what I do now. I dont know how many barrels I have cut but its a good amount so I feel like I have a good handle on whats in the normal range for bore straightness. I only dial the end I am working on (you will see why). With that method the other end will runout in the lathe. I would say the normal range of tir is about .025" or so. You will see up to .050" sometimes and sometimes its almost zero. I have never seen any correlation to accuracy here. Now I have seen some with real heavy diamond flutes runout around .100" But only a few.
Now to the story. I dial in a blank for a customer and notice the runout is quite bad. I cut the chamber and flip it to crown and its even worse. So I throw and indicator on it and we are running out over .300". Thats 3x worse than anything I have seen. Ok, call the manufacture. No problem. They will replace it. Call the customer. I explain the situation. They will make you a new one, no problem. But its not in stock. He was anxious to get shooting so he decided to try it. Knowing if there was any issue, we'd get him a new barrel. I explained he would have elevation issues. I clock the barrels up, so it would effect elevation, but not windage. Dialing only one end takes that curve out of the picture, so the throat looked just as centered as any other barrel. The curve was very obvious to the eye, it was a consistent curve like a banana for those interested. I told him to keep me in the loop, good or bad. I said, it wouldn't surprise me if it was the best you ever have, it also wouldn't surprise me if it was the worst. Anyhow, I just got this email. It put a smile on my face, I had to laugh.

thanks for sharing that. your stuff is always worth reading and ive learned from it. I do my own barrels but rest assured if i ever have somebody chamber one for me I will try to get you first. I sure wont use the backstabbers( u know who i meen)

 

[Kracken McGraw]

Maybe especially useful for a uphill running shot.

 

[L.Sherm]

Alex got a question, have you noticed any
correlation in straighter vrs more runout in barrels being more ' finnicky" or staying in tune longer.
Like a straighter one being more " forgiving" I guess is what I'm trying to say.

 

[xr650rRider]

You can actually straighten barrels that are that far out. You might run out of scope adjustment with that much run-out.

About 8 months ago a buddy came by and had gotten a call for a last minute muzzle loader mule deer hunt in Colorado on private land he was leaving in 3 days. The story goes back 20+ years, when 12 of us ordered Encore muzzle loaders at the same time. He had shot his 3 times with pyrodex and after having to clean with hot water, exclaimed that he'd never shoot a muzzle loader again. We live in Texas, so here they are no advantage as you'd have to use them during regular rifle season. We never applied for muzzle loader tags, so they sat unused, he tried to give his away several times.
So he'd asked if I had powder and bullets and I did but I haven't had mine out in 20 years either. He takes them out and proceeds to sight in the factory iron sights (no scopes in Colorado). Sight bottomed out and all the way to the left and still shooting 8" high and 6" right at 100 yards. He tries mine and it's actually worse. I told him he was cockeyed and had to be him. Another buddies was still in box and he gets it and at least gets within 4" and calls it good. They actually killed 2 nice mule deer.
When they returned from hunt, I'd read where the QLA (quick load adapter) was sometimes a problem and put barrel in lathe and dialed in the muzzle. With muzzle indicated in, the chamber end had 0.240" of run-out. I cut the QLA off and re-crowned but didn't change the sight alignment. Put barrel back in lathe between centers and every 4", found high spot and wrote the run-out on barrel. Made a delrin adapter for hydraulic press and put barrel on V-blocks and proceeded to straighten both barrels. Got sights back in center of adjustment. I can only assume every barrel we got in that order was somehow fouled up.
I recalled that when I got mine, I originally mounted a 4-12x scope, ran out of windage and elevation. Put on a 3-9x, same thing. Finally tried a 2-7 and it had enough adjustment. Just didn't make the connection at the time.

I actually tried the log first and it actually helped but afraid it would distort the relatively thin barrels.

 

[2thdk]

John Krieger mentioned this exact same thing on Erik Cortina’s podcast, “Believe the Target.” John mentioned he had a customer that always loved curved barrels with a lot of run out because he knew they would always shoot the best. Lol

 

[ChrisNZ]

My old Palma rifle was converted to an F-TR rig for my son. When the previous Krieger finally died, it was replaced with a 32" Broughton which was a reject from a batch of (national team) barrels. The reject aspect was a pronounced curve in the bore. My gunsmith chambered it with the curve indexed up and that thing is a tackdriver!

 

[Alex Wheeler]

Alex

Thanks for sharing. I always try to read your posts.
Be interesting if someone had the test equipment and tested the banana against a barrel that was nice and straight.
I wonder if the banana barrel would show less vibration ?

In the end all that matter is how they shoot.

Hal

Hal, I dont know about that? The mass of the bullet would "load" the barrel a little I would have to believe. For it to veer off its original corse that much in that short of a distance has to be a pretty good load. But I could be thinking about it wrong.

 

[Alex Wheeler]

Alex got a question, have you noticed any
correlation in straighter vrs more runout in barrels being more ' finnicky" or staying in tune longer.
Like a straighter one being more " forgiving" I guess is what I'm trying to say.

No, I have tracked some of the straightest and least straight I have had in the lathe over the years. For a while I was interested in that. It may sound strange but if there where two barrels on the table and one had the "normal" runout and one was dead nuts straight, Id pick the one with normal runout.

 

[Kracken McGraw]

I still remember those gorilla handed trap shooters bending the 870 barrels over bags of shot out in the parking lot, trying to get a curved barrel to compensate for the rising targets.

 

[Herzo]

I acquired a model1896 Swedish Mauser built in 1899 that shot 20" to the right at 100 yards even with the front sight drifted as far as possible to compensate. Upon examination, I determined a distinct bend in the barrel. Having nothing to lose, I straightened it in my hydraulic press. The rifle has acquitted itself very well in the CMP sniper (300 & 600 yard) competition.

 

[dusterdave173]

Here you go

 

[KMart]

I still remember those gorilla handed trap shooters bending the 870 barrels over bags of shot out in the parking lot, trying to get a curved barrel to compensate for the rising targets.

You are dating yourself. That was back in the days before adjustable stocks could be had. John Hall bent a BT 99 barrel for me, but used a more crude method. It looked like he was using the gun as a pry bar. Had to be careful not to go too far and put a kink in the rib.