so .260 would be about my best bet?
In my opinion Yes.
Nothing wrong with the 7 WSM except you will have to have a magnum bolt face and
they are notorious for feeding problems unless you install a center feed mag box. and
you will need a muzzle break if the barrel is light.
Don't get me wrong I have built many 7 WSMs and I own one myself and did a lot of testing
on barrel length. starting with a 26" and cutting 1" at a time off found that 23" was the
minimum without losing to much velocity. Keep in mind that it is the ballistic equal of the
7mm Rem Mag and needs 70+grs of slow powder to be at 98 to 100% powder density and
with a short barrel it produces a big muzzle flash.
The 260 and the 7/08 works well with less than 50grs of powder and for what you want to
do the 120 gr bullet will produce 3150 ft/sec with 45 grs of Varget with very mild recoil with
no brake.also it has a standard bolt face.
The 243,260,7/08 and the 308s are trouble free and very accurate and based on what you
said about expense and difficulty in getting components I based my opinion on that information.
There is nothing wrong with other calibers mentioned but for short barrels 18"to 22" the 308
based cartridges work very well. And being a NATO round 308 brass should be readily available
and can be necked down to 7/08 or 260 easy.
The choice is yours and the more opinions the better.
J E CUSTOM