MagPro maybe the answer for H450/WW785 users who where left behind when they were discontinued.
Caliber 270 Winchester Case length Min: 2.520
Barrel: H&S precision 24" Max: 2.540
Case: Remington Cartridge length Min: 3.065
Primer: CCI 200 Max: 3.340
Bullet Bullet Powder Start Start Start Maximum Maximum Maximum
Make Weight Type Load Velocity Pressure Load Velocity Pressure AOL
Type Grains grains Fps kPsi Grains Fps kPsi inches
Sierra SPBT 130 Magpro 58.5 2919 48.6 65.0 3234 63.2 3.250
Hornady SPFB
Nosler Partition
Sierra SPBT Game King 150 Magpro 55.4 2725 50.9 61.5 3000 63.6 3.250
Hornady SPFB
Nosler Ballistic Tip
WARNING!! ALWAYS BEGIN LOADING AT THE RECOMMENDED MINIMUM OR "START" LOAD
From my experience with the .270 case WW785 burned a little slower and provide higher velocity then H4831. WMR, which replaced WW785, is another Winchester powder that has been discontinued.
Both H450 and WW785 where manufactured by Olin. The same powder was sold as WW785 Ball powder, and H450 was sold as Spherical powder. Ball was a trademark of Winchester-Western Powders (Olin) and could not be used by Hodgdon. Publish data will show a slight difference in loads I believe that is a variance between production lots.
I am unaware of any MagPro Data for the 6.5X55. Last spring I started working on 6.5 loads with WMR but quit because I wanted to save my supply to use with the .270, which is my primary hunting round. I easily achieve 2600 f.p.s.with a 140 grain bullet using H4831 in the 6.5 Swede and decided to be happy with that. While H4831 does not flowing smoothly as a ball/Spherical powder it is not an issue when I am loading close to a maximum load because I weigh each charge on a scale. I have not tried H4831SC.
You can find additional Mag Pro Data at this link.
http://www.accuratepowder.com/reloading.htmHodgdon describess H450 as having a burning rate similar to H4831.