Originally Posted by jmden
My Wyatt's Extended Mag box on a Rem 700 LA is 4". Might want to make sure which one you have. A 3.9"+ OAL will cycle through it just fine. I would think that with the RUM case length and the lenth of the 300SMK, you'll want every fraction of inch you can get in the mag to maximize case capacity. Just my ramblings...
See Shawn C. website. Ther you will find all the info for 338edge, load, powders, bullets, etc.