Feasibility of a swappable barrel rifle

[dakota.potts]

As you can see, I'm a student of gunsmithing at Piedmont Technical College and I like to work on gun projects outside of school also.

One thing I've thought of doing that would be really cool is a rifle that can take advantage of the cheap 7.62x39 ammo that I have, and maybe one that can use the same bolt to replace it with a 6.5mm barrel and shoot 6.5 Grendel ammo. Pipe dream? I don't know.

We have access to a machine shop and we'll be using it to ream our chamber blanks for the .30-06 project guns we're making.

What's the feasibility of converting a factory rifle to something that can feed these cartridges and swap out barrels without requiring torque wrenches, headspacing, and other headaches every time you want to change them out?

My first thought is a Mini-mauser type action, probably something like the Zastava since the CZ 527 (which I'd love to have anyways) is more expensive. I assume these barrels are threaded into the receiver, which makes me think an adapter could be formed to go into the threads where the two barrels could be cut to lock into the same position every time (after being headspaced properly) and held into place with an external nut and a wrench.

My other thought is something like the H&R Handi-Rifle which is designed to have barrels that can be changed. Barrels would most likely have to be made or converted for this, though, and I really think the bolt action would be the more interesting and useful of the two.

What do you think?

 

[DaleA]

I'll play. I have NO experience in doing this but hey this is the internet...

For replacing barrels isn't Savage the way to go?

TC might also be something worth looking into.

https://www.tcarms.com/firearms/bolt-action-rifles/dimension/components

 

[dakota.potts]

I may look into the Savage system. I was really looking for a mini-length action for the low weight. Maybe something based on their .223 line. Would probably involve modifications to both the bolt face and the magazine, which may not be a bad thing.

T/C does seem to be the way to go for swapping barrels frequently, but I was looking for a project rather than a complete market solution. Something in the middle "buying the whole system ready to go" and "starting with a receiver you cut on a wire EDM from a piece of steel stock"

 

[barnbwt]

"Something in the middle "buying the whole system ready to go" and "starting with a receiver you cut on a wire EDM from a piece of steel stock""

Buy an AR15 barrel/extension and an AR bolt. Go from there to build a bolt action (this is basically what the Dimension is, after all). Alternately, buy a Dimension bolt/barrel.

Otherwise, you're basically looking at turning a threaded-barrel action like a Mauser into a take-down. Believe it or not, the fictional dream of barrel swapping never really took off in the bolt rifle world like it did for ARs (I say fictitious since hardly anyone actually swaps these things around very often in practice ). Considering you have to re-sight each time, or have a dedicated sight on each barrel (like the Dimension), you may as well buy a whole new gun each time, and have a respectable gun collection instead of what looks like a bunch of plumbing supplies

TCB

 

[taylorce1]

I'd look at the Sauer 202 and Blaser R8 barrel switching mechanisms. Savage barrel nut is an easy way to make most rifle switch barrels. Then there is always the interrupted thread option where it's a 90 turn and you've locked the barrel in, and a latch system on the forearm keeps it from loosening.

 

[Jim Watson]

Once upon a time, there were switch barrel benchrest rifles. You could shoot the same action, stock, and scope in different divisions. Each barrel was fitted and headspaced normally. The trick was that they were not screwed in very tight, an internal receiver wrench and a short handled barrel wrench would take one out and screw the other in to a reference mark.

No reason not to MAKE a Savage nut type conversion for any action you like, either. The main project would be making a barrel nut with the same internal threads as the action.

 

[Gunplummer]

I have owned quite a few T/D rifles and made some, or spare barrels for T/D rifles. Still have some. The 99 Savage is the king of T/D guns, but the object there was easy transportation. They work quite well to make extra barrels for, but I would stay with lower pressure rounds. I believe that the 99 worked out so well because they used square threads on their T/D guns. I would stay away from depending on 55* or 60* threads for a take down barrel. The Japanese even tried using buttress threads (Type 100) and had problems with the threads loosening up. Take a good look at the Type II Arisaka action and barrel. I made barrels for them and it is a very quick, strong design. Most T/D's seem to repeat rather well, with open sights. Most repeat well with a scope. That is a strike against multiple barrel guns. The scope. I never tried, but I guess if you had two scopes with weaver style bases, one for each caliber, it could be done.
About 15 years ago Winchester was marketing a Model 70 T/D. I remember seeing it in a sales catalog. I have no idea how they locked up, but zero was guaranteed. I never saw one or heard about them other than that. Might be worth looking into.

 

[handlerer2]

Taylorforce beat me to it. I was going to mention the Blaser and the Dakota Traveler. They are not cheap at all.

I'm not sure about short action in the Dakota.

TC Encore is another single shot possibility. I don't believe case length is an issue with these.

Didn't WildAlaska used to endorse the Blaser?

 

[dakota.potts]

The more I think about it, the more it looks like the Savage might be the way to go. I don't have interest in spending a lot of money in a rifle I don't have a particular need for, but rather having a project to work on. The Savage makes sense because it's already built in a way that accepts some barrel changes and is relatively inexpensive. At worst, I'll have to profile and thread/chamber my own barrels, which is something I could figure out.

I'm also looking for something economical. I may have a decent job, but I'm also a college student with loans to pay into, so paying lots of money for something that I don't get to work on doesn't really make sense.

So I think I'll start with something like the Savage Axis .223, sell the stock and barrel, open up the bolt head to 7.62X39/PPC size, and install the correct extractor parts. Then it's only a matter of upgrading/bedding the stock (probably Boyd's), acquiring/making barrels in 7.62X39 and 6.5 Grendel, and doing the finishing touches. I could probably make a tool to make changing the barrels expedient if not possible in the field. I probably wouldn't need to change them on the fly. It would be a matter of using the 7.62 for cheap blasting at the 100 yard range and maybe close range uses, and then setting it up in 6.5 for longer range shooting at a private range and maybe some longer range hunting uses. Might see about getting a shorter 7.62 barrel and maybe installing iron sights. We'll see at this point. Just some pre-planning for my next project.

I'd also like to send away my first Form 1 for a silencer soon, a bolt rifle could be a cool gun to get it set up on. Especially if I can find some x39 subsonic loads.

 

[gyvel]

Take a look at this web page for more ideas:

http://milpas.cc/rifles/ZFiles/Bolt...ratroop Rifles/Japanese Paratroop Rifles.html

 

[Scorch]

What's the feasibility of converting a factory rifle to something that can feed these cartridges and swap out barrels without requiring torque wrenches, headspacing, and other headaches every time you want to change them out?

I just finished building a switch-barrel set for a customer in 366 DGW (9.3X 416 Rigby) and 416 Rigby, built on a CZ 550 Safari Magnum action. We designed a coupling plate similar to the Griffin & Howe takedown rifles so the rifle can be broken down and barrels swapped using only simple hand tools (in this case an Allen wrench). This is his African rifle, as some countries in Africa limit how many guns you can bring into the country (typically 3). This takes care of 2 rifles (medium and heavy) but only counts as one. He wanted to bring in a shotgun to take advantage of bird shooting, now he can.

My first thought is a Mini-mauser type action

That would work very well.

For replacing barrels isn't Savage the way to go?

No. For the Savage system, you need a sturdy bench, a barrel vise and an action wrench. You can't carry all that with you in the field.

 

[dakota.potts]

Scorch, that is very interesting. Would you mind posting pictures of that set up? I'd understand if you consider that a "trade secret" since that's how you make your money.

The closest thing I've come up with so far is something like a trunnion (think H&K G3) with the barrel set to headspace and pinned in, which would then slide into a corresponding stop and be locked down with something like a barrel nut.

 

[emcon5]

For replacing barrels in the field, the way to go is like what is done on machine guns. Throw a lever, pull out one barrel, slap in another.

No reason that couldn't be incorporated in to the design of a bolt action. to change calibers.

 

[Scorch]

Sauer built a line of switch barrel rifles years ago. They are somewhat popular in Europe due to limitations of firearms ownership. There is Blaser as well. Very simple switch barrel sets, but they are designed as switch barrel from the get-go, not as an afterthought. Look online for Griffin & Howe switch barrel rifles.

I did not take pictures of the CZ 550, I will see the customer later this month when he comes in to pay for the other rifle I am building for his daughter, I will ask him to bring it by and get you a pic.

 

[Gunplummer]

There is the difference. "Designed from the get-go". Modified guns usually start to build up weight and get bulky. The post about starting with an AR receiver style extension and building from there is a pretty good idea for the short rounds you want to deal with. The headspace is trapped in the bolt and barrel. I always wanted to try tapering the chamber area of a barrel and the receiver socket and using a wedge to lock it. That would have to repeat alignment (In theory). The problem would be unlocking it after it was seated tight. Picture separating a morse taper shank drill from a holder after it is in there good and tight. You will be surprised what little problems pop up once you start in on this. I would suggest starting with an inexpensive action and go from there.

 

[Hunter Customs]

You are not the only one that's had thoughts of a multi-caliber rifle.
Go to www.rivermangunworks.com and check out the MBR.
A MBR is still on my wish list.

Best Regards
Bob Hunter

 

[Huffmanite]

FWIW, some small company here in the Houston area, came up with idea of making something like a Savage barrel nut system for mauser actions.

 

[Gunplummer]

There seems to be confusion between "Take down" guns and "Take apart" guns. Somebody explain to me the big difference between a Savage jam nut system and a conventional threaded barrel system. Where does the "Take down" part come in? I could put timing marks on two different barrels and swap them also. I have seen factory guns assembled in this manner.

 

[ballisti]

The Mauser M03 is a switch-barrel gun. The bolt head, magazine and barrel switches. It will go from pipsqueak to magnum.

 

[T. O'Heir]

The H&R Handi-Rifle isn't really designed as a switch barrel. Barrels have to be factory fitted to the individual receiver vs just buying a barrel like you can a shotgun.
In any case, switch barrel systems aren't new. Goes back to BP days, as I recall. Like Gunplummer says, they're not all 'Take down'. And the Savage's still require tools. 'Take down' they ain't.
However, I'd be studying how those take downs actually work.