I have an 1884 Springfield Armory Trapdoor rifle in excellent condition throughout. I am shooting 405gr. lead bullets with a low-pressure charge for the guns and my safety. It has the Buffington rear sight and an original 1884 rifle front sight blade (was missing when I acquired the rifle), It is shooting about a foot and a half high and six inches to the right at 50 yards. I can adjust the rear sight for windage, but cannot lower the sight for elevation, any suggestions? Is there a taller front sight and I purchased the wrong one? Does anyone know how tall the front sight should be? Also is the low-pressure load possibly causing the shooting high? I will only use loads safe for an original trapdoor, not modern loads for say for a lever action nor commercial loads offered in say Walmart or LGS.

It would have been originally zero much further than 50 yards.

This is from The Trapdoor Collector website;

WHY DOES MY GUN SHOOT HIGH?
The reason that all antique military arms shoot high is twofold. One, the modern loads available over the counter do not match the ballistics of the cartridge(s) for which the sights were designed. The other reason is that the lowest sight graduation (with leaf down) is often the "battle sight" setting, which, for the trapdoor and Krag, is approximately 250 yards. The .45-70, particularly, has a rather sharply curved trajectory, compared to modern arms. To be ON at 250 yards will put you WAY high at 100 yds, where many people start their shooting. There are two fixes for the later models which have removable front sight blades: (1) fit a 1/8" or 3/16" taller blade, and file it down until the gun is shooting where you want it, with the load you are using, or, if you do not want to modify the gun, do what shooters with solid front sights have to do - "stack" your targets. Center one bullseye about 12" above the other - aim at the low one, you will impact on the high one. Adjust center-to-center spacing until you get it just right. Of course, if you are just shooting for group size (and you have understanding friends) a nice tight cluster, even up in the white is OK!

I realize that 50 yards is not realistic zero and I did not have 100 yards at my disposal to sight in on but 18 inches or more high at 50 yards would make the zero nearer 300 yards. The sights lowest setting is 150 yards, even at that the gun is incredibly high at 100 yards, by 6 inches or more, I haven't attempted to paper it at 100 yards yet let alone 200 yards. Thank you for the post though.

If you zero a 45/70 at 100 yards it will be -8.4 at 150. A ballistics table is your friend

The sights were designed around a 500gr bullet, and 70gr of black powder...... and even then it's going to shoot high out to 100-150 yards

Try 65gr of FF black behind the heavier bullet, or 60 with the 405 ....use as much filler as necessary

https://www.ar15.com/forums/general/Trapdoor_Springfield_model_of_1884_Buffington_rear_sight_question_____/5-812841/

I had the same issue shooting 18” high at the typical 100 yard distance. The 1884 has the advantage the front sight blade is pinned into the base. I took a large flat washer cut it in a triangle shape, drilled a hole for the pin, then went to the range with a file. Shoot a couple file a little and so on until it was on for 100 yards with the sight leaf in lowest position.

I was thinking of doing something similar and keeping the original sight in a safe place so I or my heirs could restore it back to original.

Mine is the same way, it's normal for how these were sighted.  One of these days I'll swap the front sight out for one I can file and get it on at 100.  

You forgot the mandatory picture of your trapdoor!

Surprisingly mine was pretty much dead on with my handloads.

FYI if you do make a tAller front sight, and have a full length rifle, after the sight replacement the front blade is tall enough to prevent the bayonet from sliding on

That's a good looking gun.

Thanks. It really is in fantastic shape.