The seven-millimeters form a ladder. Each rung up adds velocity, and each costs something in recoil, powder and barrel life. Knowing the rungs makes it easier to pick the cartridge you will actually enjoy shooting. The bottom rungs: mild and moderate The 6.8 SPC is the smallest rung, an AR-15 round for modest ranges, and its loads are at 6.8 spc ammo for sale. The 7mm-08, a .308 case necked to...