DF I am certain the 28 Nosler holds more powder. I never measured case water capacity with a bullet seated but the case itself hold 90 gr of water to the top of the neck.There will be tiny differences based on brass internal construction, thickness, etc etc.
(Not that it matters a whole lot but it might be more accurate to say that the 300 Win Mag is nothing more than a 7mm Mashburn Super necked up,and with a shorter neck since (a) the Mashburn came first; and (b)both cartridges share a similar case length, the only two belted cases i know of with that case length.This has made me wonder where Winchester came up with that case length. Maybe some WW engineer saw a Mashburn.?..)
Neither here nor there but good to understand the timeline of how we got where we "were"....
Velocities are as interesting as case capacity and here's what I've seen from the Mashburn,and this includes my rifle and a few belonging to others. Barrels are 24" unless otherwise indicated:
My rifle: 175-73 gr H1000 for 3075.
160/162- 75.5 gr H1000 for 3200 (loads with Retumbo and RL25 boost this to 3250 without a sweat and good case life.
I have not fed mine any bullet lighter than 160 in full Mashburn loads, but my FF load (to make brass) with 139 Hornady -65 IMR4350- gives 3150-3190;about like a 280AI.
These velocities are about identical to the velocities obtained by my buddy,and by Scotty Beretz on here, from their rifles. The loads are so uniformly similar, rifle to rifle,that we could shoot each other's loads.
Dave 7mm uses the 150 BT at somewhere between 3250-3300 fps in his Mashburn Super. Dober uses the same load in his. Laker on here has one and shoots the 150 BT but don't recall his velocity and don't know what his loads are.
RCamuglia on here uses the new 195 gr Berger at (IIRC) 2965 with 72 gr H1000 from a 28" barrel,from his 7mm Mashburn Super. I know Rick has run his to over 1500 yards and is happy with it.
I'm in close contact with most all these guys,and they reported as they did load work up.
In any event these velocities are substantial enough that I am not going to worry about how much the 28 Nosler beats it. I'm also not paying much for brass since I'm using that common 300 Win Mag stuff.
Besides, doing all these cartridge comparisons gives a guy a headache. I'll just stick with what i got...
