I'm wondering if I could find a "donor" rifle in .308 and have it rebored to .358? I prefer the rotary magazine to the removable clip and as I understand it the rotary magazines are cartridge specific, but since the .358 is just a necked up .308 I figure it should be a simple conversion? Is barrel wall thickness an issue? Is there anything obvious I'm missing with my thoughts?
A few members, myself included, have had JES rebore post-mil .308W 99Es to .358W so the conversion is doable.
The factory rotor in my E would feed the top .358 cartridge from the rotary magazine. However, loading a second round in the magazine would jam the rotor. Fortunately, included in the rebore service, at no additional charge, JES modified the rotor to load, feed and function correctly with a full magazine. Looking at the modified rotor, it appears the fix was only a couple of strokes with a file where the rotor cradles the cartridge necks . It should be mentioned that some factory .308 rotors will load and feed .358 just fine too.
My E as a .308W was not particularly accurate even though the chamber, bore and crown looked as perfect as Savage 99 barrels can be. After JES rebored it to a 3 groove, 1/12 twist, .358, it now shoots very close to MOA. Many groups start with two touching and the third opening the group to 1-1/4". The most amusing acquired feature is that squib loads with .38 special pistol bullets will shoot into a single .40 caliber ragged hole at 25 yds. That is better than a lot of .22 LRs can do.
IIRC, there was a post in another forum thread where John Barsness explained that often rebores improves poor accuracy in some barrels because the rebore process relieves detrimental stresses in the barrel metal.
I have replaced the inelegant, heavy Beech wood furniture with more graceful and lighter Walnut F buttstock and EG fore arm. The .358W E weights only 2 oz more than my .308W F. After hunting with both rifles for a couple of years, I find that I prefer to carry the E with the 20" barrel than the F with it's 22" barrel.
I realize that JES is not an option for you but Is there not a rebore specialist gunsmith in Canada? If so, I see nothing obvious missing in your thinking.
