Well, I have to say I also agree the 32/20 is a bit "small"for Deer. Having said that, and this applies to the majority of people with the same opinion too. The factory ballistics of the 32-20 are light for deer.
The Marlin is quite capaple of increasing these ballistics. The 32-20 loadings are built to a pressure limit of 16K, The Marlin is built with modern steels and fully and conservitavely capaple of increasing those pressures to lo 20's in pressure.
Some years back Shooting Times Editor Rick Jamison did a nice write up using the Marlin and a Ruger NEW model both chambered in 32-20. These loads where able to get a 100XTP and 100g SPEER HP (disc) bullets to 2200 fps!! Now personally I feel this wile possible its use on a deer may not be so great as the bullets will likey over expand at such velocities. (I have this issue and can supply digital files if you would like.)
Recienty with the advent of the 327 Magnum, Speer now makes a 115G GD SP bullet that could be a perfect 32-20 bullet for higher velocities! I have loaded it and its accurate, but I have yet to test or shoot anything with it.
I have a couple 32-20's and two of them will handle these loadings. One is a Handi in a stubbed barrel from a 303 SMLE Enfield so its twist rate makes it a great candidate for heavier bullets like the 123g from the 7.62x39. These loadings shoot really well and may be just the ticket for shooting deer at close ranges. So far I have chronographed them to about 1800 fps, but powder cap is a limiting factor.
IMHO, iF your gonna do this, I suggest you shoot calm deer at close ranges with perfectly placed shots. Then work up a loading thats above normal 32-20 loadings but somewhat shy of these top loadings. Its an apealing idea for me as well...
CW