Newbie load/sighting questions

I am new to the MH scene, with fairly extensive centerfire handloading experience. Reading here and first shoot at the range is proving that the two are very different.

The question I have come to in sighting in with a Traditions Vortek Ultralight LDR Magnum western, is that when shooting a TC 370 gr. maxiball with 110 gr of Tripple 7 FFg, and using musket caps, I am getting good groups. As I have worked the loads up to the 110gr of powder, and adjusted for maximum elevation on the rear open sights (factory sight) I remain 10 inches low at 100 yards.

The question specifically is can/should I continue to work powder loads upwards to increase velocity and "flatten" trajectory so that I can zero at 100 yards, can increased powder move impact up the target by 10 inches with the same bullet, or is it more of sight issue and I should be looking for an upgraded sight to install on the gun? I am ok with some additional recoil with the powder increase, but seems as though I should be able to zero at 100 yards with this load.

For referrence, I have shot a 320 grain maxiball and it is about 8 inches high with the same load and no change to the sights.

Application is for elk hunting, so my intuition is for the heavier bullet.

Any advice is most appreciated.

I hope someone has info one. I have the same issue with the non-ultralight model.
I have used the lighter bullets in the past and have had trouble finding a load that shoots well. After a lot of internet searching I went up the a 450gr. no excuse bullet recommended on here. Now, with my peeprib sight fully elevated I am shooting about 8" low. Best grouping I've had with this rifle but very low.
My hunting buddy has the same gun and sights. with the same load he is hitting 3" high at 100 yards and his rear peep is about 3/4 up the riser. This gun has been very frustrating!

Went shooting again today. Found some hotter caps, and using the same load (110 gr Tripple 7 FFg and 370gr maxiball). With hotter caps, I shot 1 1/2 inch high at 50yds, 2 inches low at 100yds, and 9 inches low at 150. Shot sub MOA group at 100 yds with the factory open sites. I am good with this for now, and after this hunt will probably work on getting a peep site installed with greater elevation adjustment.

Shooting sub moa with open sights at 100 yards you better be good with it.

so... many variables, different lot numbers on caps and powder will affect trajectory. Most are/should be happy with 3-3.5" groups @ 100 yrds. IMO, If you switch to a solid hollow point brass or copper bullet you can reduce weight and increase velocity without sacrificing penetration and gain flatter trajectory.