I'm running a standard 30-06.Winchester cases give me a bit more volume over Remington cases,so I run Winchester.I use WLRM primers because I also load for magnum rifles,so I just use magnum primers in my 308 Win and 30-06 loads now.They worked great,so I just buy magnums now.The 30-06 case it's self is an amazing design.It just works with so many different powders.With the Improved or Gibbs versions,with the right powders,bullet weights and barrel lengths,I can only imagine what kind of velocities they can produce.Reloader 26 has opened my eyes up to how well that powder works with 180 and 200gr bullets.With a 180gr,63.5grs R-26,I'm getting 2890fps out of my 23" barreled 30-06,2882fps out of my 24"barreled 30-06 and 3021fps out of my 28" barrel 30-06.With a 200gr,using 61.0grs of R-26 I got 2815fps out of the 28".So R-26,if you have some or can find some,should work wonders in the improved cases.I have a good amount of the old discontinued Winchester WXR.I get 2997fps with a 180gr bullet with 62.0grs of WXR out of my 28" barrel 30-06.That was close to what I was getting with the R-26.WXR and Reloader-22 were made in the same factory as Norma MRP.They were both supposedly MRP powder that didn't make Norma's specs for MRP. I compared the WXR with some R-22 I had at the time in one of my 7mags loaded the same.I was getting about 15fps more with the WXR,about what you might see from different lots of the same powder.These powders really seem to excel with the 180gr + bullet weights.They should also be great choices in the improved cases.