I'm sorry sir but your info is mistaken... that was settled in Federal court several years back... so long as the appropriate stocks/grips are used with the appropriate barrel lengths it's permissable to switch from rifle to pistol configurations or vice versa... if you have a rifle buttstock on it the barrel must be in excess of 16"... any length barrel with a pistol grip on it... a phone call to T/C customer service will confirm this...

and yes the 375H&H barrels are very accurate as well as the 22-250... and another nice thing about the 22-250 barrels from T/C is they use a 1-12" twist... mine shoots WW 64gr SP's extremely accurately...