Swap between Buffington and ramp backsights?

OK Trapdoor fans, don't scream! This is a serious question: I would like to buy a Trapdoor, with the Buffington sight, as they quite simply outshoot most other military BP cartridge rifles, especially with aged eyeballs. But some competitions insist on open sights and do not permit rifles with Buffington sights to compete in the military class. The answer would be to buy a Buffington trapdoor and swap the backsight temporarily as needed. But this is only realistic if the swap is a simple screw off/screw on alteration.

So: do the two types of backsight have the same fixing hole spacing, or would the ramp backsight have to be altered to fit in place of the Buffington?
(I know that it doesn't work the other way around, because of the notch in the barrel band.)

For those who are worried by this idea: my rifles are tools, mostly hard-used tools, not museum showpieces.

IIRC the spacing and hole size are the same for all of the models of 'trapdoor' Springfield rifle sights. The screws may be of different length and head size.

The rear sight hole spacing, location relative to receiver, and threading are IDENTICAL for ALL .45 caliber trapdoors, period. The screws do change, and the lower band is different as to top profile. However, all of the components are readily available at a reasonable price, and may be swapped in less time than in took me to type this. So, "no worries"!

Thanks for the answers. So now all I have to do is find an affordable Trapdoor in good shooting condition. That might take a while...

Patrick - Some of the 1873 Springfield rear-sight screws are of the "un-slotted" type. These are trickier to remove than the later screws, with screw-driver slots.

ALL of the "ramp" type sights (M1873, M1877, M1879) were originally shipped from the Armory with slotless screws, except for the long-range rifles which had a slightly different (more pronounced dome) form to the head. Any other such sights now found with slotted screws had them changed - most by sources unknown. The Buffington was the only TD sight originally issued with slotted screws. A number of slotted screws on ramp sights will show signs off being hand-slotted. Slotless screws offered for sale today frequently have little stab marks at the edge where they were grabbed with a sharp-edged tool to extract them in a hurry, or where the preferred collet tool proved ineffective, when replacing sights en masse.

What a strange idea! Slotless screws! I cannot think of another example, and can only surmise that someone thought it was a clever trick to prevent non-armory personnel from removing the sights. Like the "reversed" screw heads on the Enfield No. 4 foresight, which, as Peter Laidler informs us, were often enough replaced with normal screws by the armorers if the original was FUBARed!

Patrick - that was the stated reason.

Finally, finally!
Like the Martini-Henry, this has been a wait of some years. But I now have a Model 1884 with the 1879 ramp sight. A beautiful construction, but fiddly to dismantle.

Why dismantle? Because when I tried out my "trap" the shots held a satisfyingly small vertical spread, but wandered from left to right. After ruminating about band tension, warped wood etc, I realised that the slider was too sloppy and could rotate a couple of degrees, so that when cleaning between shots - placing the rifle sights-down on a soft pad, so that the crud fell out of the trap - I was nudging the slider. At least I hope that was the cause - I'll find out next time! So the sight was dismantled, cleaned, tightened up and reassembled.

Examining the rifle to see what else it could be, the answer is nothing, except that the cleaning rod is very, very tight. If I remove the rod, the nose cap is a fraction of a mm clear of the barrel and the front band is not tight. If I insert the rod - which requires some force to make it snap into position, the front band is extremely tight and I reckon the spring is squashed flat. It all feels like a force-fit.

Now before I start filing around, I would like to hear from Trapdoor shooters: Does a Trapdoor group better if the cleaning rod is removed?

Patrick - There is a flat-spring with a 'stud' that is fitted and pinned in the Trapdoor forearm tip. The stud locks into the groove that goes around the heavy part of the 'clearing-rod'.

If the flat-spring is broke, I've heard it can effect accuracy, but, this would be rare.

Actually, you are suppose to pull or bow the 'ram-rod/clearing-rod' away from the barrel, before you pull it forward. This helps disengage the 'stud' from the Rod's groove and makes withdrawal and insertion of the Rod easier.

For shooting purposes, the Rod should be left in place.

Attachment 90666

Actually, pulling the rod away from the barrel before pulling it forward is REQUIRED as it cannot be pulled straight out. Another cause for the rod being "tight" is buildup of 100+ years of crud in the rod hole. Since you have a later rifle, you will find that there is a clean-out hole under the trigger guard. Get the hole squeaky clean and the rod can be manipulated much easier. As to "in" or "out", rifles, loads, holds, etc. vary. Try what works best for you. As to the rules regarding sights, I'm very sorry to hear that anyone would be so picky, IF the arm is of the period and unaltered. If one arm had a better sight, kudos to the designer and to heck with the others.

If you remove your trigger guard, be VERY careful so as not to start a chip. Some guards will fall out when the screws are removed, but on higher-grade specimens they can be VERY tight. Unscrew them a partial turn and see iif the guard will wiggle. Usually it is safer to lift the metal at the rear end - most chips occur at the front.

Thanks to all for the replies. I was aware that the rod needed to be pulled away from the muzzle in order to clear the stud. And the rod hole is clear. But I was shocked by the sheer force required to bend it outwards - so much force that I was worried about permanently bending the rod. I think I am going to have to dismantle the front end... it is all an implausibly rigid force-fit when the rod is in place.

The rods are tempered - one of the inspections involves bending it over a curved oaken form where it is not allowed to take a permanent set. Yes, they CAN be bent, but not by the simple act of being taken in and out. As far as the dirt is concerned - the rod should be free to move (even if only very slightly) when stowed. If you cannot discern a little bit of movement, something is binding. Back to shooting - the rod can affect barrel harmonics, try some groups with and without, if you notice a difference, proceed accordingly.