Handirifle, Using Speers 270 grain Gold Dot at a velocity of 1575, I have a point blank range (using a 4" circle) of 125 yards. If memory serves, far point zero is 109 yards and the bullet is 6" low at 150 yards with an energy of about 800 ft pounds left at that range.
While I can't put numbers for the 45-70 on paper off my head, the simple answer to your question is yes, the 45-70 using down loaded 300 grain bullets will mirror almost exactly in energy and trajectory the 44 Mag, when loaded velocity for velocity. What the 45-70 will do that the 44 Mag won't is comfortably drive 400 grain bullets to the same velocities that a 44 drives a 300, thereby increasing the energy you can deliver to a target. Compare a 45-70 driving a 400 grain bullet at 1600 fps to a 44 Mag driving a 300 grain bullet to 1600 fps and it becomes clear that the 45-70 even using low velocity loads is superior to the 44 Mag driving lighter bullets to equal velocities. And with the 45-70, there is nowhere to go but up. Also think about the fact that a 45-70 driving a 400 grain bullet to 1600 fps is the ballistic twin of the highly tauted elephant killing 475 Linebaugh driving 400 grain bullets to 1600 fps. Hmmmmmmm
This is exactly why I got a 45-70 Handi Rifle, but I have become enarmored with my 30-30 of late. I do think that many try to drive bullets from the 45-70 faster than is nessicary. As a comparison, think of a 12 guage slug launched at 1600 fps. (a typical slug velocity)A one ounce slug weighs 437 grains. A 45-70 400 grainer weighs almost exactly a 22 long rifle bullet less. It has a better BC and has a higher sectional density. Generally, a 45-70 so loaded will give 50 yard 12 guage performance at 100 yards, with a flatter trajectory to boot. If I had to choose between having a 45-70 and having a 44 Mag, the 45-70 would win hands down.
I have been thinking pretty seriously of the 445 Super Mag of late, this should give at least a 300 fps gain over the 44 Mag and while brass is expensive, one can still use 44 Mag ammo in the chamber as the 445 is simply the 44 case lengthened by .3", to 1.610, the same length as the 357 Maximum. I am beginning to think that the 445 SuperMag is everything that a 44 carbine shooter wants their 44 Mag to be. But the 45-70 will still match and outperform either.
melduja, I would be absolutely frightened of any load driving driving a 240 grain bullet from a 44 Mag case at 2200 fps. That velocity is what I would expect to see from 444 Marlin starting loads for a bullet of that weight. The typical 44 Mag Carbine pushes a 240 grain bullet to 1700 and not greater than 1800 fps. My Handi clocks about 1750 with full loads of H110 and DJ's 250 grain cast bullet. I would be surprised that one could get enough H110 in a 44 case to reach that velocity. Be careful.