I'm sure a 45-70 will kill at suprising ranges. If you are going to be taking shots past 200-250 yds. there are better choices IMHO.
One of the best Factory offerings in this caliber has a drop of -28" @ 300yds. and that is sighting the rifle in 3" high at 100 yds.
Anything further than that, you'll have an arc like a mortar round, making hits to the vitals alot more difficult to pull off.
It's a great rifle and caliber, but it ain't no long range rig.
That's just a fact.
JM
How is that a fact? The 45-70 has been and still used in competition out to 1000 yards and beyound. The old Buffalo hunters would sneek up on a herd at a good vantage point and start shooting as the herd moved away they routinely contunued to knock down Bison to well past 600 yards.
Not a long range cartridge? Maybe not your choice, but it has been and still is used at long range to great effect
In fact I saw a video of a guy that used a vintage Remington Rolling Block with black power loads to hit a target 5 times in row with the open sites at 1140 yards. Impressed me!!