Considering the Marlins are short throated and require rather deeply seated bullets, one would have to use powders such as 4198 or Reloader #7 with the 500gr. in the .450 Marlin.
; My years of experience and mucho experimentation with the .458 2" (1/10" shorter than the .450) has shown it to be worthwhile for the heavier bullets of 500gr. and more. I cannot say what the pressures were, certainly too high for a lever gun. I was pushing 510gr. Winchester solids at 2,060fps with both IMR 4320 and H335. These loads wouldn't fit in the Marlin for sure, but I'm also quite satisfied the Marlin .450 would drive them to 1,700fps. Is that enough? I don't know.
; I should also note the throat of my bolt gun was rather long and delivered ballistics as if the case was 2.2" long, not it's physical length of 2".
; My own choice in a Marlin lever gun would also be the .450Marlin, IF, and only if it comes out in a 22" barrel. The only .450's the stores around here can get are the 18-1/2" jobs - 3 1/2" short for me to desire at this point. If and when the rifle comes out in 22", I'll have one in a heart-beat for a guide gun. The heavy jacketed 350gr. Speers or even the 400gr. Barnes flat noses at just over or around 2,100fps will do any job I would have for them, from slaying in-camp grizzlies to dropping wounded moose.
: The capacity of the .45/70 is a bit greater than the .450 (I don't believe 10%), but then, the .450 will handle max pressure for the gun a bit better than the .45/70 will do, due to the .450's heavier web section, greater base mass.
; I wondered if someone would bring this round up in htis discussion - it's a great ctg. in my books and superior to the older round.
: Both the .45/70 and .450 will deliver 400gr. bullets at inexcess of 2,000fps. Yes the SD is low, so what. If the bullet is up to the job, and the accuracy of the shooter matches that capability, the round will get the job done - as Brian Pierce proved with a 300fps lower velocity load, something in the 1,750 range, I seem to recall.
; Is it the ultimate for buff - he$$ no, but it was certainly adequate and will put out close to 4,000fpe for those who think those numbers mean something.
: It surprises me no end to read where guys would take on buff with a 9.3 with factory ammo, yet shun the more powerful round just because it's not a bolt gun or $20,000 double.
: Adequate bullet, velocity and accuracy are the only criteria necessary. Perhaps those who fight against this round and the .45/70 merely reflect their feelings of inadequacy in the accuracy department - maybe I'm just full of it - hahahaha!