.338 lapua. COAL is 3.755. accurate mag site says lengths given (3.715, 3.775, 3.850) are length of magazine. Brownells site says the lengths are the length of cartridge. So for anyone who has these, would the 3.775 or 3.85 be the correct mag.
Do you already have the bottom metal or chassis? If so that dictates what you need. 3.85 is referred to as CIP length. My 3.775 mags measure 3.704 on the inside so I'd say you need the CIP length