Never mind the doubters...
That said, Sarco and Numrich have stocks for like 30$ --but they'll look like hell
Jason41987, the K31 doesn't actually lock into the barrel (like the AR15 barrel extension), though I'm certain the Swiss wish they'd thought of that since it'd have been even harder to machine
. The K31 is unlike most barrel/receiver constructions in that the back side of the bolt (side which resists pressure when firing) is milled into the receiver, while the front side of the bolt (which pushes back as the bolt is turned for primary extraction) is milled into the barrel tang. I suppose this was billed as a way to make both operations simpler, but in practice you now have
two parts that can't be made without sophisticated tooling instead of one. Most bolt actions have both the front and back bearing faces of the bolt contained inside the receiver bridge, or the handle is used as the extraction lug by dragging on in inclined ramp on the receiver body.
The "rebarreling" job developed for the K31, if you
really want to call it that
, is to chop it to a couple inches long, bore it out and thread it, and screw in the new barrel
. It works, and gets a new barrel onto a worn out action, but it's about as bubba as bubba gets, aesthetically. It really isn't worth it unless
that particular K31 has a hold on you (i.e. you've trained with it as a competitive shooter for decades and you're too old to learn another before you die
). And besides, there's no way in hell you can improve upon the perfection that is the K31 (maybe a better buttpad and more visible sights/optics, but that's pretty much it)
Takedown Steyr M95 with double set triggers
By contrast, the Steyr M95 is a much better candidate for a straight-pull rebarrel. They're cheap, much simpler, sturdier when it comes to the bolt/carrier interface (the K31 has one lug in a cam slot, the Steyr has two), have a bigger design envelope for new cartridges (K31 can't fit 30-06, the M95 can fit 8mm Mauser), and best of all...the barrel is connected just like a Mauser. Turn a blank, turn a tang/shoulder, thread it (12tpi, IIRC), relieve breechface for the extractor and bolt-face rim, and then figure out how to get the mag to work.
Getting the magazine to work is the toughest part with the most unknowns, and holds true for any rechambering project that isn't very similar to the original. The Steyr can be readily converted to 7.62x54 and 30-40 with no other changes to the feeding setup (Mannlicher clips), but any other round will require work. My rechambering project (back burnered until I finish making the reamer) is converting a Steyr into 50 Alaskan. Instead of fighting with the clips, I intend to carve out the entire magwell and go with a box mag of some sort, fed by
K31 style clips which are the bestest ever made! I'll also make a new stock from several planks laminated over an internal steel reinforcing "skeleton" to take the much stronger recoil of the Alaskan.
Before choosing any action or cartridge pairing, be sure to do a bolt thrust calculation (which is
not comparing peak pressures* or recoil); if the new round is more powerful than the old and conversions are not time-tested by others,
be vewwy vewwy careful proceeding further. If the new round is the same or less than the old (like 50AK vs 8mm Steyr), you got nothin' to worry about
.
TCB
*In the unique-ish case of the Steyr, I would not go above the original peak pressures of the original proven cartridges (8mm Steyr being the hottest of them) for the reason that a pierced primer becomes more likely. Since nothing but firing-pin spring pressure keeps the bolt turned against the sleeve into the locking lugs, pressure from a pierced primer
may push the bolt sleeve backward as it flows down the firing pin channel. This will
unlock the pressurized breech. These old guns weren't designed with much "gas handling" features like modern designs, and won't handle a kaboom as well. That said, a Bing search for "Steyr M95 Kaboom" yields no results, so..."fly Quantas--never crashed"