Changing Barrels

Hunter

Hunter

Throwin' Up Spray
If I want to change barrels on, say, a BAT action do I need to worry about headspace or how tight to torque the barrel -- assuming the new barrel is/was chambered and threaded by a competent gunsmith? If so, what do I need to do?

Would it matter if the old and new barrels were chambered/threaded by different gunsmiths?

Based on conversations with a few shooters, it seems that all they do is unscrew the old and screw on the new. Is that right?
 
A competent gunsmith would like to have the action once to take measurements just to be on the safe side. Then it becomes as simplistic as some would like you to believe it is.
 
The key words are "competent Gunsmith".

Most modern actions are very close in their tolerances. Bats, Pandas, Stillers, and a few others have set dimensions that a Gunsmith can adhere to that allows a shooter to interchange barrels with no worry.

Changing a barrel on a Benchrest Rifle is really just an exercise in common sense. First, you have have a barrel vice that will hold he barrel secure so as to loosen and tighten the barrel. You then have to have a proper action wrench for that action.

Secure the barrel in the barrel vice, insert the action wrench properly, and turn counterclockwise until it breaks free. Once it so loose, loosen the barrel vice and screw the barrel out by hand.

Take the new barrel, and make sure the threads and face are clean. Apply a thin coat of what ever anti-seize compound you like to the threads and to the face. Hold the rifle verticle, and gently insert the barrel into the threads, making sure it is going in straight. Screw the new barrel in by hand until it contacts the shoulder. A note: if at anytime it stops, or gets tight, STOP. Something is amiss. Nothing is worse than galling a Stainless Steel Barrel in a Stainless Steel Action.

Put the barrel in the barrel vice and secure it. I like to use a piece of note pad paper to add friction. Insert the action wrench and tighten.

Now, here is the part where many disagree. How tight is tight enough. What I like to do is seat the barrel firmly against the action face, and then, with a sharpie pen, make a mark from the barrel to the action. Then, I tighten the barrel until these two marks are about 3/32 to 1/8 inch separating them. That will probably take about 75/80 ft pounds of torque, depending on the action. The attached picture shows this.

Nothing is worse than NOT getting the barrel tight enough. I have cured more than one shooter's ill shooting rifle by doing nothing more than tightening the barrel. Years ago, somebody made the statement that all you had to do was snap the barrel against the action face by hand and it would be tight enough. Who ever said this probably was hoping everybody he was shooting against would follow his advice.

http://benchrest.com/attachment.php?attachmentid=15850&stc=1&d=1422931842
 

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jackie schmidt said:
Apply a thin coat of what ever anti-seize compound you like to the threads and to the face....l

What I like to do is seat the barrel firmly against the action face....That will probably take about 75/80 ft pounds of torque, depending on the action.
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What anti-seize compound do you recommend?

I assume you "seat the barrel firmly against the action face" by hand only (i.e., without using the wrench). Is that correct?

Can you generate 75/80 ft pounds of torque with a Davidson-style, side-entry action wrench?
 
Hunter said:
What anti-seize compound do you recommend?

I assume you "seat the barrel firmly against the action face" by hand only (i.e., without using the wrench). Is that correct?

Can you generate 75/80 ft pounds of torque with a Davidson-style, side-entry action wrench?
Click to expand...

Yes and more. You just never know. This is why I always use a torque wrench.
 
tzander said:
Yes and more. You just never know. This is why I always use a torque wrench.
Click to expand...

I always use a "witness mark" so I know the barrel actually advanced.

As for the initial seating, I firm it up pretty good against the shouldrer, place the marks, and tighten. I do use a cheater pipe.

This is the anti-seize I use, because we buy it by the case at my Shop.
 

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The stock and action glue has nothing to do with it. Hes tightening the action to the barrel the stock is just hanging there
 
I use action wrenches and barrel vises all the time (but on pillar beds with the stock removed). On a glue-in I realize nothing touches the stock. Was just curious if undoing a barrel with 75 - 80 ft/lbs of applied torque puts any strain on the glue after many swaps. Doesn't sound like it's an issue though.

-Lee
www.singleactions.com
 
Yea its no issue. You do have to be aware that the stock wont spin around and hit something when it breaks loose. Major party foul if you tear up a paint job on a c clamp or something
 
If the action wrench fits properly, the only force applied is to the action ring in way of the lug abuntments.

I have never had an issue with the glue in being compromised by installing and removing barrels.
 
Port wrenches can sometimes have a bit of play and get into the paint. If it's close, don't do it. The wrench will flex a bit and get into the paint.

If it won't come loose by hand, hold all the "play" out and hit the wrench hard with something big. The harder, the better.
 
anti sieze

I was told that you could use bolt grease or mobil 1 synthetic grease. Does anyone know if you can use the mobil 1 synthetic grease on the barrel threads?
Drags
 
Harold Vaughn did some interesting experiments in this area, with different materials to prevent galling, testing for barrel action joint stability. This is what I got from his writing. We are after more than simply preventing galling. We want a joint between barrel and action that is stable, so that one does not move in relation to the other when the rifle is fired. There are things that work perfectly for the prevention of galling, that do not produce the most stable joint. Having said that, the results that Jackie has gotten with his material and method, speak for themselves.
 
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Drags said:
I was told that you could use bolt grease or mobil 1 synthetic grease. Does anyone know if you can use the mobil 1 synthetic grease on the barrel threads?
Drags[/QUOTE



yes, I know several fellas that prefer a grease compared to antiseize . just make sure your threads are clean, before you apply your lubricant of choice, grease or what have you. I like copper antiseize. lee
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