Dialing in a barrel

Comparisons, opinions and choices

I initially came to this site with a bit of desire and little knowledge-----looking for someone to tell me the absolute, unconditional "best" way to do barrel jobs.

I soon learned that many of the finest machinists and gunsmiths used different methods------for various reasons.

I've seen some fine barrel jobs done with a steady rest but have never actually done it-----don't think I should comment.

Most of the "through the headstock" discussions have boiled down to the "Gritters" method or the "throat/muzzle" method. Both methods work with the right man on the lathe---so----its still the Indian, not the arrow, maybe.

Gritters Method:

I think the Gritters method offers the best entry of the bullet into the lands, especially. if the designated throat area happens to be in a curved area. There is less compromise using this method----better chance to approach "tangent to the bore". A plus ? A minus ?

Ignoring the muzzle and then making a choice on indexing the muzzle to vertical. A plus ? A minus ?

Firing forces might not be straight back and square to the bolt face. A plus ? A minus ?

Without the whole barrel OD running somewhat true, there can be quite a bit of vibration at higher spindle speeds when cutting the crown.
A plus ? A minus ?


Throat/muzzle:

Its been repeated many times that this method allows barrel changing at matches with good odds that the first shot will be on the sighter portion of the target.
A plus ? A minus ?

In very simple terms----the bullet starts and ends its barrel trip on the same axis. A plus ? A minus ?

Firing forces straight back and hopefully square to the bolt face. A plus ? A minus ?

The whole barrel OD is running somewhat true and there is less vibration at higher spindle speeds when cutting the crown. A plus ? A minus ?

Comparison and choice:

How can a person bump all this "on paper stuff" around and make a "best method" decision ? Throat/muzzle----for those who have the equipment----seems to be more logical and simple for my experience-limited viewpoint.

Other opinions ?

A. Weldy
 
No sweat-----

on the disagreement. I'm listening now.

A. Weldy
 
Latest comment I have gotten back from one of the top benchrest gunsmiths about the Viper video:

"That…is incredibility stupid. He needs to take a machining trade school class or two."
 
I don't see what having the muzzle in the centerline has anything to do with anything anyway. what are we talking about here really, .015 at the most. I bet I wouldn't know the difference. Lee
 
stool said:
skeet...really ??
it is along metal bar....
if the two ends are not close to the same planes....then there is no way a spot 3 or 4 inches on either side of the single dialed in spot can be in the same planes as the dial in spot...

if you dial in at the breech at two points, then you have the mass of the rest of the bbl rotating, unsupported, trying to work against the dial in you did.
Click to expand...


Guys, guys, guys you are forgetting that 2 lines make a straight point!!
 
Latest feedback from a professional benchrest gunsmith about the VIPER video;

t’s obvious these experts are only experts of tinkering. Try to get enough barrels completed that way would be impossible if one wanted to make money doing so.


I’d like to see the finishes he gets with that method. I wonder if he can chamber at 350 RPM and 0.6 IPM like I do and get hundreds of chambers out of a reamer before it wears out? (BTW, that is 0.0017" IPR)
 
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I should have been more clear. I mean while shooting the rifle. I clock my barrels at 6 or 12. Whatever I am closest to while final fitting.

One of the very best barrels I have ever had , had a ton or run out. I mean a bunch. The smith that chambeted that barrel had me nervous as all get out while I watched that muzzle flip around in the headstock. He didn't even clock that barrel. For all I knew the high spot could have been at 3 o'clock? Don't know. It shot amazing.

No I just meant, I don't think having the muzzle not on centerline while shooting is something I would notice under recoil. That me though. I chamber like Gordy and my barrels have done quite well in the shortrange br game. Lee
 
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stool said:
gee i thought we were still talking about CHAMBERING....
i have no comment /expereince on clocking or timing a bbl muzzle...
moving on
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I always figured windage and elevation knobs would take care of "clocking or timing".

Semper Fi,

WallyW
 
Stool
So you are saying that you get the muzzle end with in .003 or .004 thousand with your spindle bore centering tool, and then indicate the chamber end in one spot and thats close enough? I'll stick to my method I think. Lee
 
The method I use my muzzle end may be .010 off on center " perhaps a little more than stools .003 .004", but I will be able to indicated true in two spots in the chamber end. I would rather give up a little more at the muzzle, so I can indicate in two spots in the chamber end. That way I know my bullets will enter the bore straight straight straight. what the bullet does after that I don't care. this just makes more since to me. that's all! Lee
 
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Many of us had the advantage of a teacher, mentor or boss that insisted we leave the 3Jaw on the shelf. Dialing in every part on the 4jaw quickly became nearly as easy as any self centering chuck. That experience allows one to wring the last few thousands or tenths out of front and rear spiders.

Is it necessary. Maybe not. But leaves one confident that he has done all that he can. And with experience it really take no more than a couple of minutes more than settling for less precision.

Semper Fi,

WallyW
 
wallyw said:
Many of us had the advantage of a teacher, mentor or boss that insisted we leave the 3Jaw on the shelf. Dialing in every part on the 4jaw quickly became nearly as easy as any self centering chuck. That experience allows one to wring the last few thousands or tenths out of front and rear spiders.

Is it necessary. Maybe not. But leaves one confident that he has done all that he can. And with experience it really take no more than a couple of minutes more than settling for less precision.

Semper Fi,

WallyW
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Wally, not only can one get closer alignment with a 4-jaw, you can get better feel of the workpiece grip with a 4-jaw.
 
Jerry
If you really see it necessary to call me out just look at a few of the past group and score matches in st Louis. This year and the end of last. Lee

Look I don't claim to have all the answers or even a few of them. I simple used my mind and trusted a certain way to accomplish my goal, that being the chamber. I trust my work simple because it works on the target and it makes since to me. That's all. Lee
 
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skeetlee said:
Jerry
If you really see it necessary to call me out just look at a few of the past group and score matches in st Louis. This year and the end of last. Lee

Look I don't claim to have all the answers or even a few of them. I simple used my mind and trusted a certain way to accomplish my goal, that being the chamber. I trust my work simple because it works on the target and it makes since to me. That's all. Lee
Click to expand...

Greg, if you are getting great results, I'm happy for you. It is just that I haven't seen your name in any match reports. Realize I don't get all the match reports but I do get the reports of most of the big shoots. If you can back up claims fine, just be able and prepared to do so.

The reason I called you out, as you put it, is some of your stated methodology doesn't make sense.
 
Jerry
I only chamber for a few close friends. The barrels I have done are shooting well. Even a 2 gun win, along with several other match wins, and top 5 finishes.
As far as me not making sence. That could be. A teacher/writer I am not. Just a simple fella. I will try to explain my thoughts and ideas better. Lee


Jerry
I did go back and read what i wrote. your right, it didnt make any sence. LOL!! I was typing on my little cell phone on my every morning country drive on the way to work. My phone has a mind of its own, and the dam letters are almost to small to see. Sorry about all that to everyone. I went back and made some changes.
 
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I got to thinking about the overhang---------

and began to think my Cushman 4 jaw probably weighs at least double what the Spider does, mebby three times more - - -. The Cushman is about 2/3 ds the length of the Spider. Oh, I took the run out out of it by facing it off on my mill using a fly cutter. It was out a bunch I didn't make the Spider, by the way.

Pete
 
Great thread ,lot of interesting views .
I have a long spindle ...very long so will be using a gig/spider for shorter barrels aswell .
My chuck extends 8" and as is , not talking much more over hang with a spider .
If the spindle bearings and headstock was designed to work with the over hang of the stock chuck why not with an 8" spider setup ?
My lathe is a toolroom DS&G lathe with a 3 bearing spindle bore setup .
 
In machining metals the generally accepted rule is when you double the overhang you increase the workpiece deflection by a factor of 4.

This also applies to the overhang of cutting tools (turning tools and endmills).
 
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