A deep subject, one that certainly gets folks fired up. While I am certainly one who stands in the standard chamberings camp, there is a lot of difference in trajectory between a bullet moving 2900 fps and one moving at 3300 fps or more. At 200 yards it makes little difference, at 400 and more it can be all the difference in the world.
There is a lot of debate on shooting at game at ranges exceeding 300 yards, some even question that. Reality is that for some hunters in some situations 400 yards is a good as it gets. Good equipment, regular and consistant practice can and does make such shooting possible. Some may question it, but if the hunter and their rig is capable, and the hunter is not taking the proverbial Hail Mary shot, I see no reason not to. It is afterall the primary purpose of a 30 or so caliber magnum, to reach out and touch 'em.
At the same time, I fail to see any purpose in using a 30 Magnum in the woods, but more and more I see hunters carrying 300 Winmags into woods that offer shots at ranges no greater than 100 yards, an occasional 150 or so. A 7-08, 308, 270, 30-06 are perfectly at home at ranges up to 300. The 30-30 has served some an entire lifetime.
For some, the hunt is about getting close, for some the hunt is about being in the outdoors at all and for some the hunt is about bringing home the bacon. As has been said by one far more a master of words than I, "Bringing home meat from the hunt is the purpose of hunting. Bringing home game is the ultimate evidence of our having gone hunting." (I'm sure I screwed that up)
The Handi is a good platform for the cartridges it is offered in and the hunting it is intended for. It is not strong enough for magnum cartridges, and I am sure the company will not offer them nor ever make a model so capable. While there seems to be a small demand, there simply is not enough money from that to justify the development of the rifle.
Many of us have hoped that NEF/Marlin would chamber the Handi for cartridges for which it is a perfect platform, 32 H&R Magnum, 7.62x39, 257 Roberts, 25-20, 25-30, 38-55, 35 Whelen, 358 Winchester and a number of others. Alas, it seems to be more of the same.