338-378wby velocity

[Country boy]

Thinking of getting a custom rifle with a hart barrel 28 inch with muzzle brake . Chambered in 338-378 wby handloaded with 180 grain accubond and 200 grain ballistic tip using IMr 7828 or IMr 4831 powder what kind of velocity should I expect ?

 

[toddc]

Reaaaaaaaaaaaaaally fast. Figure 3500+ easy on a 180. You have heard of the 300 smk?