A buddy brought over his Savage 10 .223 with a 26" varmint weight barrel to have me shorten it to 20".

No problem. We set it up on my lathe, and make the parting cut. I change out lathe bits and set the angle to cut an 11 degree crown. As I make the first pass, I notice that the bore is wobbling. Hmmm.

Out come the dial indicators, and I start spinning things to figure out what is wrong with my setup. Short answer is, nothing. The OD of the barrel runs true, but the bore is off center by 0.013". I checked the parted off barrel end, and the bore is centered in the original crown. The chamber is decently centered as well, with only 0.0015" runout. OK for a factory chamber, I am thinking.

So, I redid the crown flat and recessed. We'll see if it shoots OK, or if we need to recrown with a piloted tool.

Is this common? This seems excessive for a barrel to have a bore that far off. I rarely work on factory barrels and have not encountered a barrel from an aftermarket maker that had this issue.

This really caught me by surprise since this barrel is a tack driver. Hopefully, it still is.

Jeremy

Yes it is common on factory barrels; most people do not know how crooked their barrels really are. They are made to shoot well, not to a straightness spec. And yours does. Or did.
Cut off some military barrels and you will think .013 runout is nothing.

I don't care who makes the barrel, the bore is never exactly in the center the entire length of the bore. Only way I know of to correctly crown a barrel on the lathe is to clamp it in a four-jaw chuck and use a ranging rod to indicate the bore before cutting the crown.

A friend once leaned on me to open up the paper patch chamber of his Remington Hepburn. It was a .40 - 2 1/2" Sharps Straight. The chamber was right at the limit of what I felt was possible to single point bore. After dialing it in with the 4 jaw I looked down the bore at about 40 RPM and the bore was flopping around like a jump rope. Once the chamber was opened up it shot fine with grease groove bullets. If I was estimating the run out about half way through it was probably .040 TIR. The bore was crooked at least .020.

It really surprised me that it was that far off only 6" from the original muzzle. I haven't cut near as many barrels as you guys have, though.

John, that is what I'll do if it won't shoot the way I crowned it. I figured that a flat recessed crown was the best I could do at the time. I'll have to get a .22 cal indicator rod.

Any thoughts on the piloted cutters that PTG makes? That may be just easier and it never hurts to have more tools.

Jeremy

That is a really unusual thing to me. I was taught to check a barrel by looking thru the bore at a light source and I should see concentric circles if the barrel was straight. In fact there used to be an overhead vise used to straighten the ones that were bent. I cannot understand how this condition could exist but then I was taught in an old school of things. I have seen many crooked or bent barrels but all were easily visible thru the bore.

When I was putting on lots of muzzle brakes I encounter off center bores occasionally. Owners got P.Oed when the brake didn`t fit all the way around the barrel. Oh WELL! Call the factory.
Aloha, Mark

Bohica; I can see a customer not quite liking that look. On this one, if it were a caliber where a brake would be necessary, I wouldn't even try to fit one.

He will pick it up Monday, so we'll see how it shoots. I have a feeling it will be fine, but it just doesn't sit well with me.

Jeremy

This is one area that people should not ask, nor tell, the average shooter about, since it will only serve to panic them with unnecessary information about which he can do nothing.
I never tell my customers that they just bought an expensive blank that wobbles in the lathe. (I did tell one that 25 years ago and he still complains about it although the barrel shoots great; I won't mention the maker but it was a famous cut rifled maker.)
That serves no purpose.
If they shoot well, regardless of how they "look", then it is a good barrel.

I have crowned barrels by hand floating the lathe tool ground to a 60 degree edge and pointed. If you make a radius crown you can't see that offset bore. The target crown with the squared faced crown will show up on the 11 degree recess cut. In the 60's we cut and crowned by hacksawing the barrel off and chuck up in a 3 jaw chuck and use a block of wood to fit the headstock end. We had a several size holes bored in the wood blocks so we had a quick fit on the chamber end. The military barrels were still in the action and crown using this method. I think too much time is lost on most of the hunting rifles to set up perfect before any work is done. This was the way I was taught by P.O. Ackley's barrel man from his time in Ackley's shop in N.M. before moving it to Trinidad. I use a floating reamer hold for the chamber work as well.

I am amazed at all the poor barrels out there. Exactly HOW do they make barrels today. I can understand a deep hole drill MAYBE drifting while drilling the original hole but then does no one turn the barrel between centers to contour it and if so how is the bore off center. Only barrels I have ever seen made were cutrifle barrels made on old homemade machinery and they were pretty good ones. When I started most barrels were bought as 1 1/4" blanks and you contoured them your self after fitting. At old TSJC they even had one lathe set up as a tracer to contour barrels. That was if you liked the contour plate they used (which I didn't). I didn't and don't like my barrels to have abrupt curves on them. As I say I'm from the very old school so I'm easily confused by all the new machining magic. At my age I'm sure my memory is hazy on some points.

We are only talking in terms of thousandths of curvature; it is hard to drill a straight hole for 30 inches and have it be absolutely perfect. And when you turned those barrels I suspect you held them between centers, so you had the breech and muzzle concentric but didn't know what the center of the bore was doing. How are barrels made? Only two methods; drilling and then buttoned, broached, or single point cut. Or, Hammer forging, which does not drill a deep hole but forms the barrel from a short fat piece of steel (with a hole in it). There are really very few "poor" barrels out there; no one can stay in business making them. If you mean poor as in, having some degree of runout, then you should not look at any more of them too closely. Most barrels are actually very straight but some aren't. Savage uses the deep hole drilling and button rifling method, which makes excellent barrels, as evidenced by their usual good performance. The very old school machines and methods did not produce any better barrels; many of them have some serious bends in the bore (meaning in terms of thousandths). Don't saw them in two and you will never know it.

I definitely agree with dpcd...a little knowledge can cause a LOT of UN-NECESSARY mental stress/problems.

The first time I saw this, in a RUGER, my very well shooting baby, turned into a gigantic POS and was soon gone from my crib.

The OD of a rifle barrel isn't always turned on the bore centerline, at least in the old days, it was centerless ground, but was still within a few thou of centerline and DIDN'T cause any accuracy problems in hunting rifles except in peoples minds for the most part and GENERALLY SPEAKING.

Once I figured this out and found as long as I chambered and crowned in a 4 jaw dial indicating the bore(at BOTH ends using a spider) with a long nosed indicator, THEN turning the run out of OD of the chamber section and polished out any slight variance in the taper, the rifle always performed perfectly...even with a barrel that showed a bit of a wowee toward the center of the tube.

When I put that slight imperfection on the bottom of the receiver out of sight/out of mind, all my fears vanished...even when I didn't bother to registering that "bump in the road" the barrel still shot 1/2" or less without any other problems....no bullet walk when heating up, etc.

I think in todays world tho', many barrels are CNC'ed, on centers, then contoured the same way and finally ground to a certain polish level.

I've used mostly McGowen and a couple of Shaw barrels for the last dozen or so rifles and the have produced all the accuracy I need...most falling in the .2 to .4 range no matter the caliber, this includes two 50 cal barrels.

It's amazing the quality of even the cheapest barrels today in comparison and it depends on who you by from. A barrel maker doesn't stay in business if they produce garbage...the net soon spreads the word.

Hardly anything having to do with barrel making is done by hand and deep hole drilling, cutting rifling by all the methods with CNC/quality control and even bore polishing is done by machines.

There was at one time videos of the various barrel making processes and chambering methods. If you're interested you just have to surf the net to find them.

I once had a young soldier come into my office and say; "Sir, I am gay and I want a discharge". I replied, "No, you aren't and get out of my office".
He turned out to be a good tank crewman. I did not know nor care if he was gay or not.
Same principle applies to barrels.
Performance, not straightness.

I can't help it but I have to comment on a cheap Chinese pellet rifle I inspected once. It was .177 cal. When the barrel was breached open, You could not see thru the bore!! I always wondered whether or not the damn thing would actually be accurate? I'm almost willing to bet it was.

It doesn't really make a difference if it's straight--the bullet doesn't care how it got to the muzzle--it matters that it's pointed at the same place on every shot. That's why wasting a lot of time trying to dial-in the muzzle end when clambering the barrel is so damned foolish. A piloted reamer is going to follow the bore no matter what, just like the bullet.

Exactly right; we did lots of testing on 120mm tank cannon barrels and it was determined that the last 3 calibers (meaning 3 times bore diameter) is what determines where the projectile will go. The rest of the bore is just along for the ride. Having said that, M256 cannon tubes, made at Watervliet Arsenal, are very straight; in terms of very few millimeters over 16 feet. I can't tell you the exact specs; it is classified.

How about something from another perspective...

We human males need excuses to cover our frailties...what better than a "crooked barrel"...it was lopsided...it got bent...I saw a kink in the bore...the bore wasn't even, I felt humps and bumps when I cleaned with a tight patch...the bore wasn't polished evenly...etc., etc., etc...ad nausium, ad infinitum.

I have an early 17 Rem I bought cheap because "the bore was wiped out"...it came with a couple hundred empty brass which added to it's "value". I couldn't see any rifling at all in the barrel.

It took me a couple of months of cleaning with 7.62 which was the baddest copper cleaner back in those days. I finally got it clean right down to the metal and low and behold there WAS some rifling...starting ~9-10" down the bore... and that section looked like a washed out goat trail. My first handloads didn't do so well, so I looked at the muzzle a bit closer with a hand lens and it had some problems also so I removed the front sight, cut off 1.25" and re crowned.

It started shooting >0.5 - 4 shot groups with Rem 25 gr bullets and much less with Hornady's and when the 20 gr VMX came out it stayed consistently at .2-.3" with 4320 until it DID wear out.

I rechambered a Shilen 26" SS and after a bit of break in it's back to slightly less than .2" with a slightly different COAL and amount of 4320 and maintains that level, when I do my part, after 6-7 years and ~2500 rounds at ~4100 fs. This ISN'T the only rifle I've dealt with similar problems.

The short and long of this is the last inch or so of the muzzle has the most important job in accuracy BUT without ALL the rest being "right" you will never achieve the highest accuracy possible.

There are MANY levels of accuracy...large, medium, small and tiny game hunting, competitive target, long range, large, medium and small cal., single barrel, double barrel, pistol...etc., etc., etc.

Not to get a bit hoo-haw going but a floating reamer can wander around a bit and can get off center now and then...having the tail stock off center can cause a wobbled out chamber if using a relative solid setup for the reamer. I think any "'smith" has had this problem come up with greater or lesser degrees of "success".

Add all these up and...last but not least all the barrel dynamics in that "crooked", "lop sided" or "rough" barrel.

If these things weren't of concern then ANYONE with their off the shelf shooters would be shooting those tiny groups at 1-2000 yds...which, the last time I looked, HASN'T HAPPENED.

Another thing that comes to mind...I've never read any literature comparing a crooked barrel vs a straight barrel with accompanying slo-mo videos...OR any studies comparing bullet dynamics/inertia between the two barrels...but I have read a lot of unsubstantiated innuendo.

Just like in fluid dynamics, a straight tube flow is laminar, a crooked tube is turbulent, just like the flow of a river...put in a kink and you start a meander...how much of a problem depends on the amount of "kink" and the accuracy requirements of the shooter.

What I DO know from my limited observations and experience is a "crooked" barrel doesn't shoot quite as well as a straight one. Anytime I did get a "suspect" barrel, a rebarrel, even with a cheap A&B barrel, usually cured any accuracy problem...MY ACCURACY LEVEL...your level might be quite a bit larger.

Interesting comments tho'...lot of info to mull over.

Luck

In my years of gunsmithing (about 40 of 'em)I have had one (1) barrel which was visibly straight and was very close to being perfectly straight, in fact. Some others have been very close but many have been far from it.
When cutting and crowning, part off then dial in the bore before crowning.
When fitting a muzzle brake to an eccentric barrel follow these steps:
Set the barrel up in the four jaw chuck by indicating the bore then turn and thread for the brake. Install the brake and turn it up tight. Now indicate the outside of the barrel and turn the outside of the brake to the desired diameter, tapering down to the barrel OD if that is what you want. I turn the brake to be about .002 to .003 over barrel diameter. Then remove the brake and polish which will take it down to the barrel OD. If well done, you will end up with a brake which matches the barrel perfectly or very mearly so. Regards, Bill

Bill,

Thank you for describing your method.

Do you indicate at one point of the bore, or do you use a range rod to indicate at two point? Does it matter if you aren't looking for bench rest accuracy?

The rifle hasn't been shot yet, so I am not sure if it needs some additional work or not.

Is this just an issue with drilled barrels? I would expect hammer forged barrels to have a straighter bore given the differences in manufacturing.

Jeremy

I select a good fitting reamer bushing and indicate off that. The chamber end is dialed in on the chamber or on the tenon if there is an unthreaded portion on which to run the stylus.
Some hammer forged barrels are very straight but not all. Everyone has seen some Remington barrels which were far from straight. On the other hand, I have a couple of Swiss barrels which are hammered and which are very good. The straightest barrel in my own assortment is an old Clyde Hart barrel. Regards, Bill