A good friend just bought a like new Wby Accumark in 338-378 but it didn't come with the factory muzzle brake. I called Wby, but they won't sell it by itself. Can someone recommend a good value brake?
Thanks.
That is WAY too much cartridge to push through a 9/16 threaded muzzle. If the muzzle is too small to accommodate a larger thread, look at a clamp on brake from Witt Machine or someone else.
Last, the caliber and cartridge for a particular setup must be considered. As a rule, LRI requires a minimum of .100" of wall thickness between the groove diameter of the barrel and the root diameter of the thread being machined to the muzzle. This value is judgement based as well. A 300-378 Weatherby Magnum is a powerful cartridge with muzzle pressures significantly higher than a 308 Winchester at a given barrel length. Wall thickness should be increased accordingly.
Our experience has shown that a thin wall muzzle has the potential to "bell mouth" over time. When a crown bell mouths, the accuracy of the rifle suffers. You as the user may be compelled to think the barrel "let go" due to throat erosion when it's actually because the muzzle was threaded with too thin of a wall thickness.