Is Marlin now making the 336 lever gun chambered in the 460 S&W?

Not that I know of but it seems the most likely canidate for a 65000psi cartridge having the 450 and 444 "mags"already.

See I'm not the only 1.

you deffinately need a .223 AR-15

Where the .45 Colt is concerned,a Ruger would be the way to go.
Cor-Bon and Buffalo Bore make hot loads that most other frames can't handle.Loads up to 365 gr. are available.A Ruger Bisley model will help manage recoil.
(Other frames that can handle these loads are:Colt Anaconda,Freedom Arms,or Thompson Center Contender)

375 H&H Mag.

BINGO, we have a winner. If not one of these then get a 336 in .35 Rem.

I would add either or all a .243 or a 6mm mag or a 25-06 just to have more to play with. Could shoot varmits or deer and antelope.

A fast 338 like the 338 RUM for a long range hammer and a Marlin 1895 45-70.

JD338

i would start with a 243 a 308 a7 mag and last but not least a rem 300 ultra mag to top it off those should keep u happy fer awhile

The Marlin frame and barrel won't handle 65,000psi safely. With the 500S&W case in the barrel it would only leave .127" of steel surrounding a 65,000 psi cartridge.