Switch-Barrel: How Do They Work?

[Phil3]

If I understand it correctly, a switch-barrel gun is simply one where it is possible to quickly and easily change from one barrel to another, without having to reset the headspace. Multiple barrels are all chambered with headspace set for that gun. Therefore, if the barrel goes back on and is tightened to the same torque each time, the barrel should stop at the same place, with the same headspace. How tight do barrels have to be? I am considering building one of these, but wanted to be sure how the process worked.

Phil

[MongooseV8]

You pretty much have it. Another option is buy a Savage to build off of. All you need is a barrel nut wrench and headspace gages and you can swap any barrel you want. Its a lot cheaper and super easy after you get the hang of it. I have one action that has had at least 50 different barrels on it. I kinda have add/ocd haha.

[Phil3]

Correct me if I am wrong, but with the Savage, one would have to remove the action from the stock to get to the barrel nut, and also use headspace gauges to set the headspace each time a barrel was put on. With the conventional "shouldered" barrel that goes on a Remington, etc., the barrel is just screwed on and tightened and you are done. No need to even remove the barreled action from the stock, using the right action wrench, and no headspace gauges either. Am I missing something? I know there is an upfront hassle of having a gunsmith fitting the barrel to the action, but once that is done, seems pretty easy.

Phil

[alfred1222]

This is over my head cause I'm not a smith, but tagged for interest. Good question OP

[Bhobbs]

Correct me if I am wrong, but with the Savage, one would have to remove the action from the stock to get to the barrel nut, and also use headspace gauges to set the headspace each time a barrel was put on. With the conventional "shouldered" barrel that goes on a Remington, etc., the barrel is just screwed on and tightened and you are done. No need to even remove the barreled action from the stock, using the right action wrench, and no headspace gauges either. Am I missing something? I know there is an upfront hassle of having a gunsmith fitting the barrel to the action, but once that is done, seems pretty easy.

Phil

If I remember right, in order to remove a barrel from something like a Remington 700, you have to clamp the barrel in a vice and then use an action wrench to break the action loose from the barrel. So, I'm guessing you need to remove it from the stock before changing barrels.

[killshot44]

Phil, the guys (mostly short-range benchrest) who leave the action in the stock normally have the actions "screwed and glued", meaning bedded permanently into the stock. They can use a vice on the barrel and use an action wrench to switch barrels.

But for actions NOT "G&S"d into the stock most will pull the action to grip the barrel close to the action to prevent torque-warp. Your comments in posts 1 & 3 are correct. I switch barrels in my F-Class gun regularly.

How tight do they have to be? Most use between 50 and 65 ft lbs but if everything is perfectly trued the action will lock up regardless of the value.
Your smith should place an indexing mark on the receiver and each barrelso you can confirm it's on correctly.
Just don't forget to use some copper anti-sieze every time.

[MongooseV8]

You wont be able to remove a tapered barrel very well without removing the stock. But to be honest if pulling a stock isn't something you want to do then any switch barrel system may not be your best choice.

Also even with a switch barrel system double checking your headspace with gages is a good idea. You only have a few thousandths of an inch window to land in, and torquing to xx pounds doesn't guarantee your headspace. A bit of debris is all it takes.

In any case they are fun projects.

[Arcaporale]

All great responses above and I certainly learned something.

But to further answer to OP's question there are also weapon systems that are designed for barrel swaps with little to no tools, that can even be done in the field. The Remington MSR comes to mind.

I believe systems like this use proprietary camming mechanisms and barrels or barrel extensions.

What is the OP trying to accomplish? Have a rifle that you can easily swap barrels with when your ready for a new one? Or to have a single rifle that can run multiple calibers, barrel lengths or what not, sort of how a lot of guys may have several uppers for a single lower on their AR's?

Correct me if I am wrong, but as far as swapping barrels on a Savage action vs. a Remington, wouldn't one have to have the chamber reamed on a Remington when adding a new barrel to the action to set the correct headspace? While with a Savage one could simply set the new barrel to the proper heaspace and torque down the barrel nut and call it a day?

[Phil3]

I was considering one rifle vs two, with two barrels. This would allow one high quality scope and stock vs two stocks and two scopes that would probably have to be lesser quality to be reasonably affordable.

Yes, adding a new barrel to the Savage is certainly simpler than getting a second barrel fitted to a more conventional action.

Phil

[Arcaporale]

Ya that's a pretty cool idea, I think we will see more and more people start to do what you are wanting to do. Not just competition shooters but casual shooters and hunters too.

As far as the Savage actions, I know lots of the Remington fanboys like to put them down but they are really producing some very accurate rifles.

I can definitely vouch for their accuracy, I have a 10 FCP in .308 with the HS Precision stock. She shoots 1/2 MOA no problem with handloads if I do my part.

My buddy was so impressed with my rifle's accuracy we went out that week and got a 12 LRP in .243 win. What a sweet rifle that is!!!

It's good to know that when I shoot out my barrel or want to switch calibers it can be done pretty easily without having to send it into a smith.


Sent from my iPhone using Tapatalk 2

[ar15barrels]

Correct me if I am wrong, but with the Savage, one would have to remove the action from the stock to get to the barrel nut, and also use headspace gauges to set the headspace each time a barrel was put on. With the conventional "shouldered" barrel that goes on a Remington, etc., the barrel is just screwed on and tightened and you are done. No need to even remove the barreled action from the stock, using the right action wrench, and no headspace gauges either. Am I missing something? I know there is an upfront hassle of having a gunsmith fitting the barrel to the action, but once that is done, seems pretty easy.

Phil

You have it all correct.
Barrel swaps on barrel-nut guns are harder than on fixed-shoulder guns.
You CAN fit a barrel blank to a savage action with a shoulder, but it would have to be fit by a gunsmith just like any other shouldered-barrel gun.

[ar15barrels]

If I remember right, in order to remove a barrel from something like a Remington 700, you have to clamp the barrel in a vice and then use an action wrench to break the action loose from the barrel. So, I'm guessing you need to remove it from the stock before changing barrels.

There are action wrenches for remingtons that work with the stock still on the action.
Those types of wrenches are fine for swapping gunsmith-fitted barrels, but usually not strong enough to break loose a factory barrel that was installed by remington.

[ar15barrels]

adding a new barrel to the Savage is certainly simpler than getting a second barrel fitted to a more conventional action.

Swapping previously-fitted barrels is easier on non-barrel-nut actions.

[LynnJr]

Phil
I have Remington's and Savage's and all the tools if you want to learn how to do it and see first hand how long it takes.

Most guns that are going to get a lot of barrel swaps will have the recoil lug pinned.You don't have to have it pinned but if you don't you need to add an alignment tool to your range bag so you get the recoil lug on straight each time.f its cocked to one side it bites into your bedding.

I have a vice mounted on a receiver hitch so I can swap barrels at the range or in the field.I have seen guys use a 2x6 and a pair of C-camps o hold the vice.

I torque mine to 100 pounds after a 1.450 barrel got really loose on me at a big match several years ago but some guys just give them a good snap of the wrist to install and use a strap wrench for removal.

If your into varmint hunting were your going to really shoot a lot of ammo each day switching barrels out is much quicker than cleaning a barrel so way less down time.

If you prefer the barrel nut set-up like Savage uses you can have one installed on a Remington.You can also switch the Remington bolt to the floating head like Savage uses.

I am posting a few pictures so you can see the pinned recoil lug.

The first picture is fuzzy but it shows the action drilled to accept the pin.
The second picture shows the parts.
The third picture is terrible but it shows the pin installed into the action.
The last picture shows the recoil lug on the pin.

[ar15barrels]

I am posting a few pictures so you can see the pinned recoil lug.

The first picture is fuzzy but it shows the action drilled to accept the pin.
The second picture shows the parts.
The third picture is terrible but it shows the pin installed into the action.
The last picture shows the recoil lug on the pin.

Only one pin?
You are relying on the fit of the lug to the barrel as the second alignment point.
Hopefully those are fitted really tight.

I use two pins so I don't have to rely on the lug/barrel fit to locate the lug.