The TAC338 is specifically designed for the 338 Lapua Magnum or 378 Weatherby based cartridges. The TAC338 is also larger than the standard TAC action. It is 0.050 larger in diameter and 0.465 longer. That is needed to accommodate the 0.750 diameter bolt that we feel is necessary for this cartridge. The TAC338 actions have no feed lips and use only center feed box magazines. Bottom metal with magazines are available from many sources. The TAC338 actions use a straight bolt handle. All tactical actions feature a screw-on bolt knob. One piece picatinny rails in 0, 20 and 40 moa off set are available. The bolts have a new proprietary coating that makes them as smooth as glass.