This thread could probably go in a few places but thought I would start here. I am considering a 338 Lapua build. I am unsure of stock and mag stuff. Does a 300 grain 338 Lapua round fit in an extended mag box or do I need to go with a detachable mag of some sort? If a detachable mag, do I have the Smith ream the stock for the mag hardware? I have done a fair amount of bedding and such on standard magnums and non magnum Remington 700's but am considering stepping into the 338 genre. Curious what i need to be thinking about to wrap my head around this portion of the project. Haven't made choices on action yet but most likely custom.