I'm a big fan of tang sights on a lever action for a number of reasons. They don't ruin the balance and handling of the rifle, they don't get knocked off of zero, combined with multiple apertures or an adjustable aperture they allow the sight to be adjusted for the light conditions.
The vintage Marbles sights are may favorite as they have a ghost ting aperture for short range and or low light and or for moving targets as well as a small aperture for more precision shooting and bright light conditions.
Aperture size is important as having just enough aperture for a bright image really sharpens the focus of the front sight, especially as you get older.
The newer Marbles sights are not bad either (and cost about one half to one third as much as a good vintage sight) and you can also use interchangeable apertures and adjustable apertures on them. They also allow for windage adjustment that the older sights do not.
The Williams receiver sight is also a good option that again allows the use of different or adjustable apertures along with the option of either finger adjustable or a lower profile screw driver adjustable windage and elevation.
Burris also makes a barrel mount for their Fast Fire III red dot sight and its also a decent option as it doesn't add much weight, doesn't interfere with carrying the rifle, and doesn't upset the balance of the rifle.
If you feel you absolutely must mount a scope on a lever gun, keep it small and stay with a small fixed power or small variable 2-7 power scope.
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Trajectory wise, I zero my .30-30 lever guns at 185 yards with 150 gr RN ammo. It gives a trajectory about 4" high at 75 yards, and a maximum of about 4 3/4" high at 100-120 yards, and about 5" low at 215 yards.
With iron sights it lets me hold under the target at closer ranges so that I never obscure the target behind the front sight.
In general with rainbow trajectory cartridges like the .30-30 I recommend zeroing at about 110-120% of the max range you intend to shoot. The bullets drops fast past that max intended range so a little error in range estimate creates a lot of extra drop and you're better off shooting short of your zero than past your zero.
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If you don't intend to shoot past 100 yards, with a 150 gr RN a 125 yd zero will put you about 1.5" high at 75 yards and 1" high at 100 yards and allow plenty of margin for range estimation error and only 5" low at 180 yards. That's with iron sights and a sight height around .8".
With a scope and a sight height around 1.8" and a 125 yard zero, the 75 yard trajectory will only be about 1" high and it will be about 3/4" high at 50 and 100 yards. It will also still only be about 5" low at 180 yards.