b: I have never owned a Mashburn so cannot say;but see docbill's post above comparing the two cartridges.Keep in mind the Mashburn predated the Rem mag by quite a few years,and was likely one of the reasons for the Remington mags' existence,along with Les Bowman's work necking down the 338 Win Mag when it came out.he got non-headstamped 338 cases from Winchester;Fred Huntington put the first rifle together for Bowman.
I have(had) no way of testing pressures other than the typical methods many of us use,but my old favorite(long gone, shot out) lightweight,long throat 7RM put together by Butch Searcy did 3125 consistently with the 160 Partition;close to 3300 with the 140 Partition and 140 Bitterroot.My Dakota gives 3375 with the same bullets.It appears the Mashburn(and the Dakota) will beat these 7RM figures as note by docbill.
I will note I never had a pressure "problem" of ant kind at these velocities.Keep in mind a "throated" 7RM really becomes a 7mm Weatherby in essence;capacities are pretty much the same,and the Weatherby gets its higher velocity from being loaded to higher pressures and the Weatherby freebore.
BTW,the 140 gr,jumping that long throat,shot fabulously in my old rifle,contrary to what someitmes happens.
I suspect a guy could use these 4 cartridges with optimum loads for each(Mashburn,7RM, 7 Weatherby,and 7 Dakota) for a lifetime of hunting and never tell the difference.Page proved that these ballistics with a 175 gr bullet(yes, maybe old school
is a very tough combo to beat for soft skinned game of many types,worldwide,coming almost to the performance of a 300 mag in a light rifle,without beating you into next week.
