Hornady's 325-grain Flex Tip .458-inch bullet

[Naphtali]

The 2010 Gun Digest lists Hornady's 45/70 325-grain factory ammunition at slightly more than 2000 fps while the 450 Marlin factory load for the same bullet at more than 200 fps faster.

Since I own only Marlin 1895 rifles, a pertinent question is: Why?

Are there reloading data available from powder manufacturers showing reloads for this bullet in 45/70 brass that more closely approximate 450 data? If there are these data, please furnish link(s).

 

[Kernel]

Perhaps, because the SAAMI max ave pressure (MAP) for the .45-70 is 28,000 psi, and for the .450 Marlin it's 51,500 psi. Hornady & Marlin brought out the the .450 in order to get more performance out of .45-70 form factor guns, so of course they're going to load it hotter. That's it's whole point.

 

[Naphtali]

Most reloading data for 45/70 now includes several tiers of pressures, Marlin 1895s usually being in the highest pressure tier. So it's less likely that data for like actions will show different upper pressures that are safe and acceptable. This has been my assumption. Perhaps you know something I'm overlooking?

 

[Action_Can_Do]

Check Hornady's site. They give reloading data for the bullet that is pretty impressive.