I think I've posted these recently here, so I'm sure I'll be flame-bait for someone...
I live by the philosophy "optics are for the shooter, not the rifle." If a guy is going to shoot moderate ranges with a rifle with a low velocity - in other words, with a steeply arched trajectory - then he should be VERY confident he's aiming at the middle of the deers heart, not just aiming in the middle of the vitals, or middle of the deer.
With the .45-70, I'm happy to hunt ~300yrds without specialty planning involved in the set-up of the stand. For me, 300yrds on a deer sized target means I want 12x or 16x max zoom. I've taken game with 1-4x and 2-7x scopes at 300-500yrds, but I'd much rather take a 20yrd shot with an over powered scope than take a 300yrd shot with an under powered one.
I've never understood why so many guys claim a 3-9x40 to be too big and heavy compared to a 2-7x32mm type scope. They're bigger and heavier, sure, but they're not "big and heavy". I have a few "big and heavy" scopes, and they sure ain't 3-9x's! (NXS 5.5-22x56mm and BR 8-32x56 come to mind).
This one was taken at 250yrds with a Bushnell Elite 3200 3-9x40, which I have since replaced with a Nikon Buckmaster SF 4.5-14x40mm in the second picture.
The bullet, recovered under the hide on the far side, after liquefying the near lung, cutting the heart to ribbons, and slicing the far lung in half. Buck ran ~5yrds, jumped a fence and crumpled, made it about 10yrds on the ground.
One with the new scope - the Buckmaster gives me the option for parallax correction, as well as the ability to dial my drop instead of holding over like I had to with the duplex reticle in the "coin adjust" Bushnell Elite:
Given enough magnification to give a confirmed consistent POA, the Marlin pictured does very well. Regularly a sub-MOA rifle with the Hornady 325grn Leverevolution load, here's one such target, which isn't it's best showing, just the one I have on a hosting site:
So I guess that makes me the odd man out - I'd go with the 3-9x40mm, or even something larger.