We managed to find a .450 Marlin barrel for an extra Handi rifle receiver for use this year in the Mississippi Primitive Weapons season. (let's not travel that road too much right now). The hunter using it shoots a .308 Remington pump during regular gun season so can handle reasonable recoil. I have a BC and will hunt with it. question is, how far can I take the data I've compiled on the .45-70 in arriving at a comfortable but adequate whitetail load for the .450 Marlin. The cartridges seem to be essentially identical except for a 1/20" twist in the .450 as opposed to the 1/18" in the .45-70. How will that affect the stability of a 300gr JSP or the Lyman 330 gr cast HP at reduced velocities. Has anyone transposed loads down in these two calibers and how did it work out. I've no experience with the .450 Marlin and any and all input will be much appreciated.
:-)
stuffit
The 45-70 rifling twist your refering to, is that the Buffalo Classic? If so, H&R never did produce a 1/18 but all 45-70's both Buffalo Classic and Handi Rifle are all 1/20 rifling twist.
But you can use the same bullets and very low 45-70 loadings for the .450 Marlin. Here at Accurate Arms
PDF File for 450 Marlin You will find a load for the 400-gr Speer JSP using 4350 that will give you a slow fps of 1386.
Good luck with your loadings.