Why Can Some Rifle Barrels Be Changed Out Easily While Others Can't?

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adn258

New member
So this might sound like a newbie question, but I've mostly had AR/AK style rifles my while life. I've just now got into longer range shooting. I've swapped out AR15 barrels EASILY before.

Rifles, for example the Ruger Long Range Precision Rifles require special tools etc. or the gun can blow up in your face I've heard if the barrel isn't replaced correctly etc.

There are other longer range rifles though like the Thompson Center Dimension Rifle have some sort of modular system where barrel exchanges can be done without special tools or a gunsmith.

Why are some barrel replacements hard and almost require a gunsmith, while others are not hard to swap at all?

As always, you guys are the best! Hopefully I don't sound too ignorant of the idiosyncrasies of this here? I know that on precision rifles you need to use no-go and go gauges to check for heads pacing issues.

Why is this an issue with some rifles?
 
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Swapping an AR barrel requires special tools... SHM
receiver vise
armorers/barrel wrench
torque wrench
pin punch and bench block depending on your front sight
headspace gauges. Most people don't. but you should have it checked at the very least.

Just because the tools for AR's are reasonably common and easy to obtain does not mean they are not specialized.

As far as AK's, last I checked they were press fit.... isn't that a special tool?

The problem with a easy to change barrel systems it making it repeatable, accurate, and consistent, all while trying to put it in a reasonable form/size factor, and make it affordable.

Its just the way you are looking at it. Replacing a barrel is to some degree a gunsmithing job and thus, generally requires some specialized tools, it goes with the territory. Unless you want to spend the big bucks to get the platforms that are designed for the user to be able to swap barrels and calibers easily.

If you look into the long range and precision shooting stuff. Lots of them are shooting complete custom guns, custom action, custom barrel. Most of them have gunsmiths that ream the chamber to their exact specs, and fit the barrel to their receiver.

If your getting into longer range shooting you will be getting into hand loading. I would focus on getting your hand loads dialed in and see how far you can push your given rifle. Once you have gotten to the limits of your what your gun can do, then look at having a better barrel fitted.
 
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Why are some barrel replacements hard and almost require a gunsmith, while others are not hard to swap at all?
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Because that is the way they are designed.
There are a lot of legacy design actions from when the factory barrel was expected to last a lifetime for the hunter or soldier and turning a target rifle over to a gunsmith for barrel replacement was accepted as routine.

I doubt the Savage Nut was meant for easy barrel change by the user, it is a simple system for factory assembly.
 
Fair points guys. I also should/need to get myself some no go and go gauges for a lot of the rifles I own.
 
For an out of the box Rifle hard to beat the Savage . Not close to top of the line but a good starter and you can learn a lot .
 
adn258 said:
Fair points guys. I also should/need to get myself some no go and go gauges for a lot of the rifles I own.
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go/no-go gauges are pricey. I figure factory guns should be set up properly. I would only buy a set if you are changing a barrel on a gun to make sure it is set correctly since you are doing it yourself. Factories generally check after assembly.
 
Shadow9mm. As always, you make excellent, logical, and valid points that are very helpful. I always appreciate your help and advice so I just wanted to thank you.
 
There really aren't any rifles that are hard to swap barrels on if you have the knowledge and tools to do it.
I swap out barrel's pretty often on my precision rifle's with either Pre-fit barrel's or take a barrel blank with my action specs to my local machinist for a shouldered barrel. Chamber Reamer's can be rented pretty cheap.
 
Hmmm....You are going to find my response weird, I’ll bet.

Most barrels are “hard” to change because there is post barrel install processing.....for example, Savage has a reputation for something getting in the threads and gumming up like it is red locktite or something!

To me, easy is something like a Remington....I can take that barrel on/off all day long and have the same headspace when done. Switching barrels requires a second barrel cut to the action. When doing that, people often recut the action to true it making the old barrel no good due to changed headspace or barrel threads. Barrels done after truing should be interchangeable. Install with reasonable torque to make it easy and damage free.

To make that easier, just start with a custom action that is true to begin with.

Savage gets a reputation for being easy. Just remove the old, reinstall or replace. Well that is because you the gunsmith are setting the headspacing. Try to remove and reinstall with same exact headspacing....it is a feat of chance! Unless you index mark. It is actually the hardest and puts the most responsibility on the person doing the assembly.

AR15’s are easy enough, but you should check headspacing. I needed a bolt replacement one time to make it work.

Whenever a barrel is changed, go/no go gages should be used. Go gage only and tape can work, but is more risky.

You want easy, check out the West Texas Ordnance Switch Lug! Minutes!
 
Nathan said:
Switching barrels requires a second barrel cut to the action. When doing that, people often recut the action to true it making the old barrel no good due to changed headspace or barrel threads. Barrels done after truing should be interchangeable.
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National champions have trued up Winchester 70 receivers once then rebarreled them 2 or 3 times a year across decades of shooting.
 
Why are some barrel replacements hard and almost require a gunsmith, while others are not hard to swap at all?
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The answer is simple and obvious, because they were designed that way.

Most were designed before the modern era of "plug and play".

Believe it or not, there was a time when gun designers and gun manufacturers didn't want every 5 thumbed ape with a bench vice and a pipe wrench swapping out gun barrels. And, they had good reasons, beyond their own bottom line.

I know that on precision rifles you need to use no-go and go gauges to check for heads pacing issues.

Why is this an issue with some rifles?
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This is an issue with EVERY RIFLE!!!

Not just "some". EVERY SINGLE ONE!!! Even when the barrel maker says its not, it still is something that should be checked. For the safety of everyone who will use the rifle.

Consider this, the barrel maker may sell you a barrel that is "fully chambered" meaning they don't expect you to need to do any finish work (reaming) on the chamber. BUT, they do not have your action to check, and they have no control over what you do installing the barrel.

You MAY get lucky, and tolerances will be within safe range, but you cannot know, unless you check. Even the Army uses gauges to check the M16 headspace after a barrel change.

Changing a barrel, and doing it right, in a non-modular designed firearm is not a task for unskilled or semi skilled labor. There are even some guns where no one but the factory is set up to do the work.

Remember that you are dealing with a mechanism that must contain a 50,000psi+ explosion rather close to your face!
This is not something where its a good idea to cheap out, or where you want someone doing it that does not fully understand all the details involved, or cannot do the needed work correctly.
 
44 AMP said:
Remember that you are dealing with a mechanism that must contain a 50,000psi+ explosion rather close to your face!
This is not something where its a good idea to cheap out, or where you want someone doing it that does not fully understand all the details involved, or cannot do the needed work correctly.
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Doubtless true, but also not rocket science in many (most?) cases...
Go/No-Go gauges can be rented for less than $10 and swapping the barrel on a Savage (and similar action including the "Remage" hybrid) takes literally 5 minutes.

I think that, like reloading, a lot of people stay away from it because of the "mystique", or perceived difficulty, more than actual complications.

I think there are two categories... those that are really not that big of a deal, all you need is a "5 thumbed ape with a bench vice and a pipe wrench" and then there are the "impossible" ones, such as an unmodified Remington that simply cannot be done correctly without specialized tools.
 
Brian Pfleuger said:
such as an unmodified Remington that simply cannot be done correctly without specialized tools.
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I wonder how Remington does it. I assume they make their action as best they can to a nominal tolerance. Chambering seems like a smaller tolerance operation, so I would suppose the make plus, nominal and minus barrels....then fit them up on a fitting line?? or do they make several lug sizes....lugs would make more sense.

I wonder how Tikka does it? Is it raw machining capability, or some other fitting secret.....

I think as a volume manufacturer, you could achieve interchangeable barrels by assembling actions, measuring bolt face to action face, then final cutting the action face so they all have the same bolt face to action face length.
 
Some years ago I asked Remington and Winchester how they installed chambered barrels to headspace correctly. Both said they used the arsenal method with Garands

Each barreled action was headspace gauged with different bolts then used the bolt that closed on the GO but not on the NO GO. Then the bolt was marked with the receiver serial number.
 
There are several different methods to install and correctly headspace barrels, dependent on the design of the rifle. Rifles that have multiple bolts (or bolt heads) available. Some guns get the barrel installed and any needed headspace adjustments are done by swapping out bolts until it passes the gauge check. SMLE .303 British rifles had several difference "size" bolt heads in their field armorer's kit, so they could correct headspace by swapping out bolt heads.

We do the same with the M16 at Army direct support level maint. When we replaced the barrel, we would reinstall the original bolt carrier group and check with the gauges. If it passed, it went out the door back to the user unit. If it didn't, we changed the bolt with one from our shop stock, and repeated the process until the rifle passed the gauge check. Something similar was done with the M1s and others.

Now, civilian bolt actions (or other designs) do not lend themselves to this, simply because multiple replacement bolts are rarely available.

One method used for rebarrelling Mausers, Remingtons and other such rifles is that the newly installed barrel is "short chambered". This means that the barrel does not have the chamber cut to full correct depth. Intentionally.

The short chambered barrel is installed on the action, and then the gunsmith finish cuts the chamber to its final correct depth based off the existing bolt face. This is what "finish reamers" are for. And its why, for these kinds of rifles, a skilled professional with the right machine tools and the skill to use them is the way to go.

Other rifles, don't have the barrel screwed into the action, it slips in and is held in by a retaining nut ( the AR system in principle) which screws onto the action and traps the barrel in place.

There are other guns where the barrel is press fitted into the action using a powerful hydraulic press and removal and installation of those barrels is a job for the factory, where such tools are available.

SO, it all depends on what the design is, and allows for.
I can, and have done it all on ARs, I can do everything BUT the barrel on most other guns, because I don't have the right tools which might include a lathe and the skill to use it.

I've built numerous sporters on Mauser actions, from .22-250 to .458 Win Mag, but I had the machine work needed done by a professional. Cheaper for me, and worth every penny I paid.
 
Anyone here have any experience with the Remington that used a barrel nut like Savage does?

I can't say I'm thrilled with the bolt set up on the Savage not that there's anything wrong with it, I just think it's weird... If some one were to make a very Mauser like rifle that had user changeable barrels like the Savage system, I think it would be a hit. Like if FN decided to start using barrel nuts on the Model 70 Winchester...

Tony
 
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