The 1884 Trapdoor has the Buffington sights. So it is a ladder sight with a small aperture but very far from the eye and the front sight is a post. I shoot a 500gr cast bullet at .459. .460 and above do not shoot near as well.
My 1884
the rear sight
This is a very complicated sight, and I am going to claim, what you see in the Army sight designs, the influence of target shooting games. I know from my 1913 Small Arms book, and from other documents, Soldiers were shooting on round bull targets. There are 1000 yard targets in these period publications.
given the technology of the day, and the needs to qualify 1000 men or so in a day, these round bull targets, pulled up and down in the pits, became the "combat" course. Is a round bull in the middle of some khaki paper background representative of combat conditions? Not really, but it provided a means for enlisted and Officers to get trigger time. Some shooters became much better than others, and in time, the qualification course, the "combat" course became a game in itself.
And you can see how that influenced sight design. These 1884 sights are complex. Windage and elevation adjustments are very fine, which works well on a firing point, but not in the field. I have talked to Veterans of WW2, Vietnam and Iraq/Afghanistan. It is rare that organized shooting events happen in theater. I have pictures of a military shooting range in Iraq, the maximum distance is 100 yards. A bud of mine, Vietnam veteran, he zero'd his M14E2 at 50 yards on a 55 gallon drum. If he hit minute of oil drum, the weapon was zero'd. And improvised trash was the only practice targets around, and in a fire base, anyone firing a weapon is going to upset the rest who are going to believe there is an VC/NVA attack happening. Our last WW2 gun club veteran, he was handed an M1 carbine as he got on the troop ship. The weapon was not zero'd, in fact Sammy asked his buds where the carbine was shooting, in combat! He said he beat the rear sight dovetail with the butt of knife to drift it in the right direction. While I never asked, I don't believe anyone in his unit arrived on Iowa Jima with a sidearm that they had zero'd prior to landing. I think all of them were issued rifles, knives, etc, as they boarded the troop ship,
You can see the carry over of this trapdoor sight features in my Krag carbine
and in the M1903
The M1903 sights are not good target sights, you need a P J O'Hare micrometer for repeatable and precise elevation adjustments. And the windage marks are four MOA. You can adjust the sight in half wind marks, but anything finer than that is hit or miss. And, the tiny post front, and tiny rear aperature sights are only good against a paper target with a black bull. These sights are very hard to use in overcast conditions.
I am claiming that the target shooting game had an over sized input into US rifle design. The sights were designed for the needs of target shooters, who actually thought, combat was going to be like a shooting range. Where they could have plenty of time to dial in complex sight adjustments, without the enemy locating their positions with counter rifle fire, or artillery! And when WW1 rolled around, any head above the parapet for more than seconds, got beaned by snipers. There were thousands of hidden eyeballs, all looking for targets. If the sniper did not get you, the forward artillery observer would. And what Soldiers found in WW1 and WW2, sniping at Germans would result in the Germans returning the love with artillery shells!
I do think European rear sights tended to be more pragmatic. While the British had a target shooting ideology prior to WW1, and their Lee Enfields did have windage gauges,
All the pre War "Old Contemptible's" were gone in 9 months, and the Pal's in Kitchner's New Army hardly lasted longer. Attrition was so high, and firearm training was limited to teaching the men how to aim, load, and clean their rifles. There was not time to teach marksmanship. You see more pragmatic sights during the worse period of WW2 in the No 4 Mk1
The pre War sight had click adjustable elevation, but it took too long to make, and recruits had not the time to learn, nor space, to make use of click elevations. So this titling L sight with a
600 yard and 300 yard elevation peep. was installed in the middle of WW2. The British locked down the front sight with a special tool to prevent the Soldier from altering windage.
this PTR 91 sight is not a target sight, the windage knob as about a turn and a half of slack!, but it is easy to use, and easy to understand.
Soviet front sight to be very practical in up close, low light condtions. Just put what you want to shoot in the circle, for fast shooting, and if you have more time, the post is big, and in the middle. Easy to find. Another bonus, this front sight is very hard to damage.
An 03 sight is similiar to the Krag. Thin, and easy to damage, but the right width for the black bullseye's of the day.