derringer pistol

hello could any one tell me how a double barrel over and under mechanism works especially how the change from top to bottom is achieved a pencil drawing would be well apreciated and it would soothe my aching brain thank you

This will depend on the firearm probably, there was a very common 4 barrel pocket pistol that used a rotating firing pin to fire the 4 barrels in turn.

I seem to recall the Davis derringer used a transfer bar to fire each barrel, and some mechanism moved the position of the transfer bar so that it alternately hit each of the two firing pins.

I have a high standard double action derringer but have never taken it apart to see how it works :-).

Bill

The 4 barrel derringer is called the 4 Aces. Kinda a neat design. Like Willbird said, the firing pin rotated 45 degrees each time the hammer was cocked.

the Davis, american derringer and most modern derringers have a little ratcheting transfer bar set in the hammer which alternates on a cam between the high and low position. when the derringer fires, the cam is actually hitting the firing pin, not the hammer.

your best bet would be to buy a double barrel davis derringer at a gun show for less than $100. reverse engineer it and sell it the following month for around $100. you may lose a few bucks, but the knowledge would be worth it. no need to reinvent the wheel.

Caspian

http://www.mek-schuetzen.de/Blueprints/remington_double_derringer.gif

Looks like a ratchet and a lever.

I had to make a firing pin for a Remington as shown in the parts view above. The rachet wheel has alternating depth gullets between teeth. Each cocking of the hammer rotates the wheel one tooth. The firing pin is tipped up to fire the top barrel then on the next cocking tipped down to fire the bottom barrel. A small flat spring keeps the firing pin in contact with the wheel.

hms50

Keep in mind, too that the Remington design was a rimfire, as were a lot of the other multibarrel small "derringer style" pistols. Lots easier to deal with , as the distance the pin had to move was only from one rim to the next.

Cheers
Trevor Jones

I was thinking on the davis, one thing they did, which was smart I think, was build their gun based on CENTER fire, then they used an offset firing pin in the rimfires, the result I think is a lot more versatile design overall.

The one I had was a 22 magnum, the only problem with it was that it did not have enough firing pin impact to reliably fire some brands of 22 magnum ammo, this is not however an UNcommon problem with 22 magnum handguns from what I have read.

With the lower barrel I once put 5 shots in the X ring of a 25 yard slow fire pistol target, at 25 yards even :-)...the upper barrel shot equally as accurately, but about 18" higher at 25 yards...the lower bbl shot right to point of aim at 25 yards, overall for the price of the gun I was really surprised by accuracy and poi.

Bill