I'm being told that the factory muzzle brake does a good job. If it doesn't I have a PVA 4port Shock wave I'll put on it.I was not looking for this rifle,but I stumbled into this deal,I just simply couldn't let it pass .If I was building from scratch I would never choose the 338LM not because their is anything wrong with it at all other than cost and weight of most actions factory chambered for it in some instances. That said if you are getting a great deal on either I would say jump on it. I would not build a 338-378Wby either for the same reasons. The brass is going to kill ya for either and loaded factory ammo is no joke either. A great deal though is a great deal and they seldom come around twice!
I have never owned any of the various versions of Weatherby actions but I have shot just about every type from Commercial Mausers on up that Roy used before designing his own and all of the versions built in different places for Weatherby. I have never came across one that did not work and cycle smoothly or one that did not have great finish and fantastic wood. My favorite action would have to be the Howa made Mark V actions.
Only about 1/2 of the ones I have shot had their original barrels on them. For a long time you really only saw serious hunters with them and as you would imagine it does not take long to burn out a barrel if your shooting one regularly.
It is not hard to believe 20rd count. The recoil is fierce for many. So you have two types of Weatherby owners the guys that buy them and only shoot them rarely due to recoil and ammo cost and the guys that travel the world hunting every chance they get. The lighter weight smaller diameter cartridges that are not as punishing to shoot are the ones that are most likely to be burnt out.