I'm converting a M70 CRF to 338 Edge (formerly a 375H&H). I prefer a one piece base, but before I commit has anyone experienced loading, extraction, and/or ejection problems in these circumstances? The first question may be influenced by the second: I'd like to seat 300SMKs and 300OTMs on the rifling, but may have to single shot the rig until I determine--or not--if I can get OAL oversize cartridges to feed from the magazine well. Presently, if I remember correctly (bbl. action at Hart's) the receiver opening is but 3.60. I can lengthen the magazine box to accommodate longer loads, but what about that "hourglass" 3.60? I anticipate that some loadings may go as far as 4.0 OAL.