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

[stagpanther]

Here's a diagram of all the Savage 110 parts. Part numbers 52 and 53 are the ones used and both appear to be threaded.

I've done dozens of 110 barrel changes--never encountered one that did not have a threaded tenon for screwing into the receiver. Must have been referring to an AR I guess.

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...

The idea behind the free-floating bolt head is to minimize the necessity for blueprint truing. Like the barrel, it's pretty easy to swap out when changing cartridge head size. I totally agree about the Model 70 set-up would be nice if an end user could easily swap barrels. The bolts would have to match the barrel and set headspace at the same time, that's the tricky part. And there's getting the original off, which is generally the hardest part in rifles with no barrel nut or a nut that does not have a good surface for tool leverage.

Savage recently changed over to a small firing pin in their LA bolts which generally is a good idea IMO, but they also changed to a more complex internal system for adjusting the firing pin spring tension. In principal a good thing, too, but in the process they introduced a couple of components which are pretty weak IMO, the lock rings for the collar for example. One of those goes down and your rifle's day of shooting may be over.

 

[Jim Watson]

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.

My gunsmith, who was active in the Golden Days (pre-GCA68) did a lot of barrel changes.
He points out that the "modern" short chambered replacement barrel requires a finish reamer and headspace gauges.
In his day, barrels were chambered to maximum depth or a bit long because any serious gunsmith was going to have a lathe he could face the breech off with. No expensive reamer required, just headspace gauges. Not to mention the numerous barrels chambered with only a factory load for reference.

 

[44 AMP]

Apologies for my error about the Savage 110. I have removed the incorrect information.

My gunsmith, who was active in the Golden Days (pre-GCA68) did a lot of barrel changes.
He points out that the "modern" short chambered replacement barrel requires a finish reamer and headspace gauges.
In his day, barrels were chambered to maximum depth or a bit long because any serious gunsmith was going to have a lathe he could face the breech off with. No expensive reamer required, just headspace gauges.

He's entirely right, of course, no expensive finish reamer required, just an expensive lathe, which a gunsmith would have but a garage hobbyist most likely would not.

Back in those days, gunsmiths also dealt with a lot of barrels that had sights on them (or the holes for sight mounting) and not only did the chambers have to be right, the barrels often had to be turned a bit so that the sights would line up properly (not leaning). I have heard the term "clocked" used to refer to this, and other things.

Point is, most older designs were made with the idea that barrel replacement was something done by skilled craftsmen and usually required the use of machine tools, special tools, and the needed gauges, and was not something done by the hobbyist.

An interesting sidenote, Savage sold their rifles for many, many years, never advertising about the ease of barrel changes. It was, apparently, not considered a selling point back then. Today, from what some of you have written, it is, for you, at least.

 

[stagpanther]

Apologies for my error about the Savage 110. I have removed the incorrect information.

I figured it was an inadvertent error.

 

[Geezerbiker]

I think one of the major reasons people want user changeable barrels is for the desire for less than common rounds. How many times have you heard someone say, I'd really like a rifle in ____ caliber but I can't find one...

With user changeable barrels a fellow can try a round he's always wanted and not be out several hundred for a custom barrel job. If the round doesn't live up to expectations, that barrel isn't all that hard to sell for a small loss rather than the bath taken on selling a custom rifle.

Tony

 

[Brian Pfleuger]

An interesting sidenote, Savage sold their rifles for many, many years, never advertising about the ease of barrel changes. It was, apparently, not considered a selling point back then. Today, from what some of you have written, it is, for you, at least.

I wonder if it's just because they noticed there was *some sort* of interest and they figuring why not publicize it a little. It doesn't cost much of anything to mention it here and there.
I can't imagine the market is really that huge, I would assume it was almost never the reason someone bought a whole rifle on purpose.
Bare Savage actions sell for more than the whole guns, which is odd to me.

In my particular case, I had traded a useless to me Remington 870 12ga for a slightly less useless to me Savage 11 in .270WSM... and I figured, why not?
Cool project to swap in a custom barrel and see what I can do. :shrug:
But I never would have done it "on purpose".

 

[Jim Watson]

I have not changed a barrel on even a Savage but once.
My 110 BVSS was pretty accurate, until NRA cut the size of the F class target in half and the standards changed. A friend and I ordered up Pac Nor prefits, a nut wrench, and a Go gauge. He had a barrel vise. The factory barrel nuts were very tight - the factory installer has about a five foot cheater on HIS nut wrench - but once we got those off, it was a straightforward job.
Screw out the old barrel, screw in the new with nut backed off.
When most of the way in, insert the stripped bolt and Go gauge. Screw the barrel in against the Go gauge, then tighten the nut. Taking up all the slack in the threads adds about 1 1/2 thousandths to the minimum headspace dimension. Who needs a No-Go gauge? I never saw any sign of cases stretching with multiple reloads.

 

[Brian Pfleuger]

The factory barrel nuts were very tight - the factory installer has about a five foot cheater on HIS nut wrench - but once we got those off, it was a straightforward job.
Screw out the old barrel, screw in the new with nut backed off.
When most of the way in, insert the stripped bolt and Go gauge. Screw the barrel in against the Go gauge, then tighten the nut. Taking up all the slack in the threads adds about 1 1/2 thousandths to the minimum headspace dimension. Who needs a No-Go gauge? I never saw any sign of cases stretching with multiple reloads.

That's funny. There are lots of stories about King Kong tight Savage barrel nuts, even claims that Savage uses some sort of super duper Loctite.
Mine was uneventful. I used a towel to protect the action, held it in place with a sliding clamp, put a pipe wrench on the nut and literally stepped on it. Popped right off.
I agree about the gauges and saw the same increase when I tightened the nut. I took mine loose again, backed out the gauge, turned the barrel in slightly (it wouldn't *quite* close on the go gauge) and then cranked it down, at which point it did close on the gauge. Just because. Certainly no need for it to be that close.
I may have the world's only large shank .243. Probably not.

 

[RC20]

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.

Savage: Standard rifles have long used a fine thread and a nut. The only tool you need is a nut wrench. Nothing special or exotic, its just how the system is designed.

Many barrel mfgs supply a pre -chambered and threaded barrel. Plug and play.

Headspace does not have to be exact to previous. You want it a bit longer than a factory round. It simply fire forms to the chamber and you measure the shoulder for re-size. All head space has some variation.

It take me longer to get the run out of the stock and the scope off than it does to change and set the barrel.

Cost is a barrel nut wrench at $50 roughly, and a head space gauge.

Taking the Savage factory nut is stuck on hard in about 30% of the receivers, its easily handled and after that one is off its no longer an issue as you control the process.

Remington Standard: Remington also uses a fine thread barrel. Factory does not use a nut. YOu would need an action wrench or take it to a gunsmith for the first one.

Many barrel mfgs now make a Remage where they supply the same type of nut that Savages uses and afterwards all you need is the nut wrench.

You don't need to get exotic or specialized guns if you use one of those two.

Savage Bolt: The separate head is a feature that allows it to align in the lug area. While not a full on custom fit, it does work in that direction.
Savage did not do it for our convenience, its allows them to make the bolt in sections saving costs. But its a benefit just like the barrel system (which allowed them to save costs).

Winchester requires a gun smith to remove the barrel, then they put threads on a barrel and they have to ream the chamber. Some barrel mfgs offer partially finished barrels. Its still a cost you repeat each time you do a barrel.

For someone that shoots a lot the Savage type setup is a nice system. I have 4 rifles I have built up on that system and one rifle with two different calibers. In that case I also have two bolt heads so I can swap those calibers due to the rim being different.

 

[RC20]

Remember that you are dealing with a mechanism that must contain a 50,000psi+ explosion rather close to your face!

Guns blow up because of gas blowing back through the receiver, not the barrel. A barrel change does no affect the gas path, or how good the relief system is or is not. A gun smith does not have clue what the barrel strength is, he guys them from an mfg.

If fact he is cutting threads and its always possible he screws that up. I will take the fine threads on a Savage any day of the week.


People shoot unsupported head guns all the time.

So, yes, like changing the spark plugs in your car, you can do it.

In fact, I saw a modern Winchester (aftermath acualy) Model 70 blow up at the range.

A reloading negligence (not the shooter, he was testing for his employer)

 

[stagpanther]

I have not changed a barrel on even a Savage but once.
My 110 BVSS was pretty accurate, until NRA cut the size of the F class target in half and the standards changed. A friend and I ordered up Pac Nor prefits, a nut wrench, and a Go gauge. He had a barrel vise. The factory barrel nuts were very tight - the factory installer has about a five foot cheater on HIS nut wrench - but once we got those off, it was a straightforward job.
Screw out the old barrel, screw in the new with nut backed off.
When most of the way in, insert the stripped bolt and Go gauge. Screw the barrel in against the Go gauge, then tighten the nut. Taking up all the slack in the threads adds about 1 1/2 thousandths to the minimum headspace dimension. Who needs a No-Go gauge? I never saw any sign of cases stretching with multiple reloads.

Savage's seem to be the easiest barrel nuts to get off IMO--never had a problem with getting one off. They seem to use some kind off oddball anti seize lubricate that consists of "micro ball bearings" that I'm guessing serve to firm up the seal between the barrel's and receiver's threads.

 

[RC20]

What I found was crud in the threads of one I did (nut not the barrel threads at issue). I had to get a breaker bar on it.

What Savage shooters reported was it was not locktite but some kind of polishing or cleaning material they use and do not clear off.

That one did take some serious horsing, I wanted to save the nut but I could have just cut a slot in it with a Dremel tool.

The 30% was a guess but the material in the threads is mfg caused.

Initially I did a careful torque (I had the Torque Wrench for it) but it quickly became evident that you could do it by feel and its not an exact, no one agrees on the value (Northern Shooter Supply has a recommended of 50 ft lbs as I recall).

With the crud in the threads there can be no value listed as that is the antithesis of as good a torque as you can get (clean or lubed threads mandatory )

Even then the values can be 20% or a bit more off due to thread variation (its good enough but its certainly not exact, the latitude is in the system to allow that variation and be good)