I use 56.8 grs 3031 pushing the 350 gr Hornady RN @ 2175 fps. Lots of smack and better penetration than the 300. The 500's need to be seated too deep and generally are too long to feed well - you wind up crimping on the shoulder. We have loaded the 500 gr Barnes TSX, 40 grs 3031, load it in the pipe then back it up with the 350's in the mag, but I don't like having one in the chamber until it's needed. The 350 gr load we use was worked up to and even though Hodgdon STARTS loads for this bullet at 56.5 grs 3031, it's a real kicker at that starting load. At 57 grs we saw case expansion that seemed a bit high, and even though it was probably due to the chamber itself once in a while they were a little bit "sticky" to eject, IMO a sign of too much load. At 2175 fps, it generates 3600-3700 ft/lbs and that will stop almost anything at close range. Another option is the Nosler HG Partition 300 grainer for a bit more speed and no doubt great penetration, but at $2.00+ a bullet, my curiosity isn't quite that high. We got the Barnes 500's at a show, real cheap. One thing when loading the hot ones - get yourself a Lee factory crimp die and set them in well. No sense taking a chance. Though the spring mechanism in the Marlin's tube will probably offset the recoil it'd be a shame to find out you reseated a big bullet the one time you really NEED it!
in the .45-70, usually on top of 50-54 gr of H335. Oh, OK I do throw the odd .457 round ball downrange with 12 gr of Unique or Universal Clays under a Dacron wad...
