Mpbr
He is hitting a 10 inch gong at 276 yards with a front rest. I have had levers myself in 35 rem .30/30 and 450 marlin. I never even tried to shoot more than 200 yards for practice all my shots on game are like 50 feet. I think he needs a new rifle maybe a 308Win.
AL
To expand on what Barkbuster said...
I think what many folks are asking with questions along these lines is how far away can a given cartridge, sighted in a certain way, consistently hit a target of a certain size. I say this because, as Pisgah pointed out, if you hit exactly where you aim, it doesn't take much bullet or energy to kill a deer. The problem then becomes what trajectory is involved with making that perfect hit.
When calculating maximum point blank range (MPBR) you determine the height of your kill zone (usually around 8", on a deer), the height of your scope/open sights, the muzzle velocity (MV) and ballistic coefficient (BC). These numbers are then used to determine at what distance your bullet's travel will be 4" above, and when it will fall 4" below, line of sight. For the vast majority of shooters, regardless of what your laser range finder is telling you, MPBR is the longest shot you should take. This presumes you have calculated that number AND practiced at that distance until you can quite consistently hit that 8" circle. For those who do not practice at that range, they should not even attempt a shot at the MPBR for their cartridge.
With high MV and a good BC, you can reach out past 300 yards with many cartridges and reasonably expect to hit what you're aiming at. The 30/30 Winchester is not one of those cartridges!
"Set up a scoped .30-30 for its maximum point blank range (+/- 3") and the trajectory of the Winchester Supreme 150 grain factory load looks like this: +2.9 inches at 100 yards, +0.1" at 200 yards, -3.0" at 235 yards. The trajectory of the standard 170 grain factory load looks like this: +2.9" at 100 yards, +1.8" at 200 yards, -3.0" at 211 yards.
The 160 grain Hornady LeverEvolution factory load does a little better. Here is its trajectory: +2.9" at 100 yds, -0.2" at 200 yds, -3" at 232 yards."
The quoted information above is from Chuck Hawk's site and presumes a 6" target height. With that information, the load you specifically asked about is good out to a little past 200 yards. An 8" target height would allow shooting a little further out...perhaps 225 yards. Keep in mind that at these distances, the bullet is dropping very quickly, so calculating the exact range and then determining where to aim becomes quite complicated. (Also, this takes into the realm of "shooting" and away from hunting, but that is a whole different topic...one that is often hotly debated on this forum.)
As shown above, the LeverEvolution bullet has a better BC, so it retains velocity longer, which equates to more energy at longer distances. With sufficient practice, you could reasonably expect to not only consistently hit your target at ~250 yards, but still have the energy to make a lethal hit on a deer. If he won't be happy with killing a deer at 250 yards, with a gun that is 115 years old, I guess you can step him up to a 308 Winchester and slay things at 300+ yards.
With the way your nephew is shooting, I'd suggest leaving very-well-enough alone and just picking up some of the Hornady ammo to give him that 250 yard range/energy. Site in 3.5" high at 100 yards and that would be consistent with the shooting distance he's already practicing at, leaving nothing to be desired, as far as cleanly harvesting a deer.