I got to thinking about all the 6mms I've played with through the years...243, 6mm Rem, 240W, 6mm/284, 6x47 (6/222mag) 6mm Bullberry Improved. I liked them all. My favorite for deer size game was the 240W (90X) and for sheer fun ( which also killed a Scimitar Oryx and a couple Axis deer) was the 6x47 (85XBT). I used the 95 Ballistic tip in the 6mm/284 and made a godawful hole in an antelope doe, but it was a flat shooter. The 243 was the easiest to find ammo for, but Wildcats are more fun! lol
Personally, I wouldn't mess with a Mosin action, too many others ( inexpensive too, from Savage to Marlin to Mossbergs) I'd have to leave the old war horse Mosin in its original caliber, which is a thumper!
The action is the limiting factor, of course, for example, I really like the little CZ 527 rifles, but you are looking at the 6/45mm, and even with it your bullets have to be seated deep. Go up to any short action like a Savage/Remington type, and you can seat out the 80-85gr in a 6/47 or as mentioned, better in many regards, the 6mm/204. Of course, the 6mm PROMETHEUS is a fine barrel burner, ha. I once had a dedicated prairie dog rifle made up in 6mm Remington. Shot the 65gr Vmax. Up close, it would turn a PD into a greasy spot! Out far, you could really flip them into the air! However, even shooting slow, just a tad over 100rds showed extreme throat/leade burn...I sold it before I ruined it. I found that the little .204 ruger did almost the same thing, and my old Marlin 783 .22 mag with the 33gr Vmax factory loads was more fun. But, if we didn't experiment, what would we learn, right? have fun
