Monday, August 24, 2009

Modern Trapdoors

A fellow on a forum posted about this trapdoor. The Harrington and Richardson Trapdoors were a minor sensation, at least in my circle, when they were released. Unfortunately I couldn't afford them then. Now, I'd have bid on this one but the seller won't ship FFL to FFL and my FFL (or any others around here) will accept from a non-FFL holder. Neither am I a Curio and Relic FFL holder (cruffler). So it is a no go for me. Disappointing. It doesn't help that we had a 1877 (or later) carbine come in the shop the other day. It looks like it would be a fine shooter.

But it did cause me to start casting about for other reproduction Trapdoors. I found out that both Pedersoli (who bought Harrington and Richardson's's tooling) and Uberti make repros of the Trapdoor in rifle and carbine form. The prices are north of $550 though, way north! The cheapest I saw on sale were about $1000. However, there are some originals at about that price. Oh, sure, they may be parts guns...

The Harrington and Richardson, as shown above, was built on the 1884 design (low arch block, wider receiver, etc.) which might be the strongest Trapdoor out there although one shouldn't use loads over 18K PSI/CUP. The problem with these rifles is the locking cam and it can be dangerous if uncorrected!

The original cams are one-piece with the thumb piece on the shaft and locking cam with the bridle between the cam and thumbpiece that screws into the side of the block, holding it all together. The Harrington and Richardson and Pedersoli (Pedersoli boughth Harrington and Richardson's tooling) rifles don't use the bridle and the cam is separate from the shaft and thumbpiece and is held by a set screw. The Pedersoli rifles is square where the Harrington and Richardson is round. This means that on the Pedersoli rifles, when the set screw is tight, it won't move on that shaft at all since the hole in the cam is square to fit over the square section of the shaft. On the Harrington and Richardson, with the shaft being round, the set screw doesn't have that good of a purchase on the shaft and can (some say "will") loosen. One might either not be able to open the breech or the breech block can fly open under full pressure and eject the empty case back at the shooter.

There are three ways you to cure this problem.
- remove the cam and slide the shaft out, file a flat spot on the shaft where the set screw sits and put it back together. The flat spot won't allow the shaft to spin under the cam.
- remove the shaft and cam then drill a small hole where the set screw sits so you have a better seating surface for the set screw.
- if you want/must to keep the H&R original, loc-tite the set scew into the cam. It might still allow the shaft to spin.
I'm not sure if Pedersoli makes the trapdoor for Uberti. Both sites show the identical photo but, of course, there are slight differences in pricing. These would seem to be wonderful rifles being made on the Harrington and Richardson tooling with the exception of the aforementioned cam shaft change. Additionally, they have a more correct rear sight.

Disassembly:
1. See exploded view, below. Always check first, of course, to be sure the weapon you are about to handle is unloaded. Grasp the rifle around the barrel and wooden forearm with your left hand and point the muzzle in a safe direction. Pull back on the hammer (#A) to place it in the loading position. (Depending on the internal lockworks, you’ll hear either one or two-audible clicks.) Then open the action by lifting up on the thumb piece (#18). This will unlatch the breechblock (#11), which you can tilt all the way up and open with your other hand.

Look down into the Springfield’s action, checking to be sure there is no cartridge in the barrel’s chamber. If you can see a cartridge in the chamber, reach in and manually remove the round by pulling the cartridge up and out the top of the action. Remove all live ammunition to a separate location—somewhere well away from the area where you are working.

2. The next step is to remove the lock and the stock. If you’re working with a rifle, remove the ramrod (#32) first. For a rifle or carbine, leave the hammer still at the half-cock position, unscrew and remove the two side (or lock plate) screws (#21) from the left side of the stock. The lock (#33) assembly can now be pulled out from the right side of the stock. Be gentle and ensure that the edges of the lock plate don’t grab any slivers of the inletted stock as you remove it.

Unscrew and remove the tang screw (#20). Depress the band springs (#29) and slide the band or bands (#26 and 27) off toward the front of the barrel. The barrel and breech assembly (#2 and #1) are now free and they can be lifted straight up and out of the stock.

3. This next operation—disassembly of the breech and the breechbolt—frees the extractor, which is powered by a very strong coil spring. Hold your hand over the hinge area to prevent the loss of parts while performing this operation. With the breechbolt remaining in the open position, push out the hinge pin (#10) and lift the breechbolt out of its hinge in the breech (#1). The extractor (#7), ejector spring (#8), and spindle (#9) can also now be lifted out of the left-side hinge.

Make careful note of the relationship of these ejector/extractor parts for reassembly later. The point or tip of the ejector spindle has to be engaged with the detent at the rear of the extractor during reassembly. For this operation, it helps to have a long tapered punch to keep the extractor/breechblock holes aligned during the reassembly of the breechblock to the receiver.

When removing the barreled action from the wood, the tang screw and bands are removed and then the metal can be simply lifted out of the wood. Disassembling the breechbolt starts with unscrewing and removing the breechblock cap screw (#17). Then remove the following parts together: the cam latch (#15), the thumb piece (#18), and the breechblock cap (#16). These parts can be lifted out to the side.

The cam-latch spring (#14) is now free and can be lifted out of the breechblock. Unscrew and remove the firing-pin screw (#13) from the bottom of the breechbolt. Now the firing pin (#12) can be removed by pulling it out through the rear. Note: Some modern copies use a two-piece firing pin with a return spring.

5. To disassembe the lock, place the hammer (#A) all the way forward for this operation. Compress the mainspring (#D) using a mainspring vise, a machinist’s clamp, or a small C-clamp far enough so you can disengage it from the mainspring swivel (#EFG). Tilt the mainspring out to the side, removing it from the lock plate (#C).

Reassembly tip: Since the mainspring will have to be compressed for assembly, you may want to just leave the mainspring vise or clamp in place, setting the assembly aside until you are ready to reinstall the spring.

Unscrew the sear-spring screw (#J) and lift it and the sear spring (#H) off the lock plate. Unscrew and remove the sear screw (#L). The sear (#K) is now free and can be pulled off the lock plate. Unscrew and remove the bridle screw (#N) and lift out the bridle (#M).

Unscrew and remove the tumbler screw (#B) from the center of the hammer, and insert a straight punch into the hole in the tumbler. Be sure to use a punch that is smaller than the threads in the tumbler to prevent damaging them. Tap the punch until the hammer (#41) comes loose. Now the hammer is ready to be pulled off the tumbler. Lift away the freed tumbler (#E) from the rear side of the lock plate.

Reassembly tip: As you reassemble the lock assembly into the stock, be sure to set the hammer in the loading position. Also, hold forward on the trigger as the lock plate is being inserted back into the stock to avoid any interference with the sear.

Some items of note here: Some Springfields used a two-notch tumbler (1-safety/load and 2-full cock), but the majority seem to use the familiar three-notch tumbler (1-safety, 2-load, and 3-full cock.) On H&R reproduction Springfields, the hammer screw passes all the way through the tumbler, acting as the inside pivot point for the tumbler. Original Springfields had their pivot points forged as one piece with the tumbler.

The stock inletting holds the hinge pin in place. Once the barreled action is out of the stock, the hinge pin can be removed, freeing the bolt, the extractor, and the ejector parts.6. For disassembling the guard plate and buttplate, unscrew and remove the two guard screws (#35) from the (trigger) guard plate (#34), and carefully ease the guard plate down and out of the stock. Again, be careful with this step so that the edges of the guard plate don’t grab any slivers of the inletted stock as you remove it.

Unscrewing the two guard-bow nuts (#37) releases the guard bow (#36), which can now be pulled down and out of the guard plate. Unscrew and remove the trigger screw (#41) and the trigger (#40) will drop down and out the bottom of the guard plate. The rear sight can be removed from the barrel by simply removing the two screws that fasten the sight base to the barrel. Make note of the position of the rear sight for reassembly later.

The buttplate (#24) is easily removed by unscrewing and removing the two buttplate screws (#23). The buttplate is simply lifted off the stock to the rear. If the buttplate is equipped with a door to access a cleaning rod, remove the buttplate-door spring screw and lift off the buttplate-door spring. (Note that none of these parts are shown in the illustration.) Use a small pin punch and hammer to drift out the buttplate-door retainer pin, and lift off the retainer ring. The butt-plate door is now opened and removed by pulling it straight out the rear of the buttplate.

As always, you simply reverse the disassembly procedure above for reassembly.


Links:
- Trapdoors Galore
- Trapdoor Collectors

4 comments:

mesquite lefty said...

do you know how much the ejector should eject a case when the breech is opened? I have a uberti/stroeger and it does not remvove it from the breech when ejecting?

Hobie said...

The ejector spring pushes the extractor with enough force that it "throws" the cartridge case against the ejector stud which should deflect it out of the gun. You should hear a "snap" sound as you open the breech. That is the sound of the extractor functioning.

The extractor is so powerful that the original users found it could tear through the rims of copper cartridges which didn't have the resiliency of modern brass and wouldn't "let go" of the chamber walls. They would then have to use a knife blade to remove the case from the chamber.

If your gun won't extract properly it is probably a broken or missing extractor spring. The second likely cause is a broken extractor. I suppose you could be missing the ejector stud, that would leave the case in the trough...

mesquite lefty said...

called bernelli and they said that my carbine did not have an ejector just an extractor and I cannot find a schematic to see so I guess I can only extract

mesquite lefty said...

Just rec'd a new pedersoli springfield carbine and sold my uberti. I put a fired case in the chamber opened the breech and the case was just pushed back out of the chamber-barely. It does not eject at all-worse than the uberti. Any suggestions on what I should do with a brand new carbine to get it to eject the fired cases?
Mesquite Lefty