rdnk here is a site with some info
http://shortmags.org/shortmags/here is the latest from Fred
Important Message from Fred
Please let me inform all potential customers that the following calibers are not on our list of calibers, so there is no sense asking "please" and "why". No WSMs, nor Ultras, nor STWs, nor Wbys (outside the smaller 240 Wby). These are calibers that are not applicable to our Encore.
And further, it is my opinion that they are also too much for at least 95% of the shooters in America. Please understand that the gun writers, God bless 'em, are all victims of the printed glossy magazines, and must continually come up with stories and praise about something new and wonderful, while in reality, these new "Horsepower" calibers are probably the worst choice for our numbers.
While I'm not a particular fan of the old 270 Winchester, I do agree with the father of that choice, the great Jack O'Conner, whom I read religiously in my youth back in the 40s and 50s. (Yeah, I'm old, but not stupid.) His philosophy of a gun in a moderate caliber that becomes second nature in handling for an individual, is far more deadly than those massive "horsepower" guns, that are mostly shot with the shooter's eyes closed. It's been my pleasure on several occasions to prove to the macho types, this fact. When on the bench, I unsuspectingly slip someone a gun with an empty chamber. The embarrassment of that anticipation of huge recoil, and almost pushing the gun off the bench is enough to humble those big fella's. My point is; just shoot a gun with which you will be comfortable, and then you'll be making a well placed shot, with hopefully the correct projectile for the job at hand, and make a clean kill. Wounded game at extreme ranges is just anothermethod of giving the "Anti's" a way to get at our sport. The average shooter will do much better with a 260 Rem, 7-08 Rem, 308 Win or the fine old 284 Win. Sure we'll make you a 7mm Rem Mag, 300 Win Mag, 338 Win Mag, (among hundreds), but please be a bit more conservative in you choice of caliber, and you'll be a happy shooter for a lifetime of enjoyment.
This message was felt necessary as I am answering at least 25 messages a week, dealing with these extreme calibers. So, let's be safe, confident, and have some fun out there.
Thanks,
Fred
I also have one of his 300wsm barrels and thinking hard about having it shortened and rechambered to 308 winchester.
One of the main problems that I have found is the short throat . I started to develope a load but showed high pressure at 2 grs below max. I had the throat lengthened out 100 thousands but haven't taken to time to try it yet. With the single shot we are not restricted to bullet over all length used in a short action bolt gun. When Virgin Valley was making their barrels they were using a long throat but not sure how much. If you use factory ammo stay with the smaller grain bullets as these are shorter.