Making a take down rifle from a bolt action rifle.

[Brithunter]

Have been having a discussion about modern take down rifles for easier and more discrete transport something we have to think about in todays more anti society    just avoids hassles if they don't realise one is carrying a rifle in some cases.


So been thinking on the best way to convert a rifle. So far have considered the following:-


1) Full thread barrel take off. mean plates attached to receiver and barrel to tighten and align the retain/stop from undoing in use and also have a way yo take up wear. Hmmmm not quite as easy as first sounds.


2) Interrupted thread so a 1/4, 1/3 or even hal turn unscrews the barrel. This still runs into the same problem or allowing for wear and tear and locking it into position so it cannot loosen until you want to remove the barrel.


3) Rather that alter the receiver thread make up a threaded insert that fits into the receiver to accept the barrel. The insert can be broached with slots to allow the 1/4 twist etc removal or perhaps made with several locating/retaining lugs with close fitting shanks/tenons/spigots between the lugs to align the barrel. Sounds good but I am thinking cutting the lugs and recesses in the sleeve so as they twist they cam the barrel back against the face will be hard to get them perfect and not sure with the equipment to hand that few degrees of angle can be cut.


4) Again using a sleeve threaded into the receiver but with a shank threaded same diameter but facing the muzzle so a special threaded sleeve nut cane be tightened up to pull the barrel back in. The barrel tenon/shank can be smooth and cut with tight tolerances to align it with two tapers/ cones one at the breech face and one at sleeve face to really centralise the barrel. Something like the idea Savage has but with a more streamlined nut/sleeve and the tapers/cones to help alignment. This would of course require the fore end to be movable to allow access for a wrench to tighten the sleeve nut.


    So we have several options but which one is going to be most workable is the big question. Over the last few weeks I have had several ideas buzzing around my brain-box and for some reason #4 seems to have stuck so far. The longer bearing surface for the barrel shank should help greatly with alignment and return to zero and with two tapered cones to seat into wear in threads or lugs seems to be a non issue. Styling the nut to look sleek and working around the fore stock moving out of the way is then thing to work on. A fore end iron attached to the plate/sleeve so the fore stock can slide forwards to allow the nut to be tightened seems favourite at the moment and would allow for the barrel to be floated. Normally I am not a fan of floated barrels but as the stock will be split at the receiver ring front this might be the best option.


Thoughts on any of these and suggestion would be appreciated.

[gunnut69]

Savage originally made the 99 with an interupted thread system. They had enough problems that the system was quickly replaced with a sull threaded break down.. The forearm is removed and there is even a position to reattach the forearm further forward to give greater leverage to break the barrel loose. These seem to shoot quite well and I've never seen one critically loose. Of course the system means the forearm can't be floated,,

[TRX]

 I've seen pictures of a Chinese-made Mosin rifle that had interrupted threads in the receiver.  Search for "pharmory" on the web.


 Apparently the Chinese simple broached the locking lug raceways all the way through instead of stopping at the threads.  If you remove the barrel and milled off the appropriate sections of thread, you'd have a 1/2-turn interrupted thread attachment.  All you'd need then would be to figure a way to lock the barrel in place... note that some of the benchrest guys with "switchbarrel" guns just turn their barrels in hand tight and snug them with a rubber strap wrench or stubby aluminum wrench.  (others torque to >500 ft-lb, depending on their barrel religion...)