I just bought my first 7x57 after years of reading about its merits. I have most of those surrounding the 7's, 243, 250 sav, 6.5x55, 300 sav, '06 and 300 Win so have a number of powders etc to choose from. I bought a half case of Prvi Partizan 139 grain SP ammo for first shooting and once fired brass. Nice price at SGA! The rifle is a pretty Mexican 1947, model 36 action, nicely figured probably Fajen stock, unknown 24" barrel maker stamped only 7x57, a nice Timney trigger with side safety, a 1995-6 Leupold VARIX-II 2-7 scope and the stock is glass bedded at recoil lug and front of forend to give some upward pressure, also sling swivel studs. The barrel had a touch of light bore rust that came out with the first brass brush and Hoppe's. Military bolt cut off and swept down & back, new bolt handle welded in place, nicely done. My only question is how much pressure will this Mexican (I believe small ring) action take. I don't need to make this rifle a barn burner as I have others that can do that but I'll start low with probably IMR 4350 and a Barnes TTSX in 139-149 gr. I like those bullets in my 300 and '06 very much. Need to check the rifling twist and free bore once I have once fired cases, bullets and have checked magazine length and 0.050" off the lands OAL. Any suggestions on other starting points or cautions?
