Newbie question: trigger mechanisms


PDA






Top_Gunn
June 15, 2007, 10:08 PM
I'm a pistol shooter. We pistol people talk a lot about trigger actions: single, double, double/single, striker-fired, and some weird stuff. I've never seen a discussion of any of this in connection with semiautomatic rifles. Why not? They've got to do the same thing as pistols in the sense of getting something to hit the cartridge so it goes bang, right? My son's rifle, which I borrow sometimes, seems to be straight double action, though the trigger pull is much shorter than on any double-action pistol I've fired. Is this typical?

If you enjoyed reading about "Newbie question: trigger mechanisms" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
alucard0822
June 15, 2007, 10:20 PM
most rifles would be considered single action, the bolt retracting is what normally cocks the hammer similar in function to a 1911, some are as you put it "striker fired" bolt actions set the striker when the handle is turned, still tecnically single action.

hexidismal
June 15, 2007, 10:58 PM
When you say "my son's rifle", what rifle are we talking about here ? I... can't seem to think of any double action rifles. The thing is, most rifles don't fit into those categories. They are categorized by rifle specific actions. Although it could be said that they most resemble single actions.

MMcfpd
June 15, 2007, 11:14 PM
I suppose you might consider firing from an open bolt versus a closed bolt action - something I'm still just a bit murky on.

ETA - That's not really a trigger action, though, is it?

alucard0822
June 15, 2007, 11:26 PM
firing from an open bolt is still considered single action, as the trigger merely releases the action, but does not cock anything

basically SA=pull of the trigger allows the hammer/striker to perform a single action (release from fullcock)
DA=pull of the trigger allows the hammer/striker to perform two actions, both to bring back to fullcock, and to release.

both cocking and releasing are necesary for any gun to fire, but if cocking is not by direct mechanical linkage to a trigger, like say gas pressure acting on a piston, a lever retracting a bolt that pushes the hammer to fullcock, or a hammer that has to be cocked by thumb.

I am only aware of two double action mechanisms used in long guns, one was a design by schofield that was basically a big double action revolver with a long barell and a stock, and the other was an odd 20ga sears roebuck field gun that my dad had, single shot break action, but the exposed hammer was double action, all other guns like this either cocked when the action was opened, or cocked manually with the thumb.

but being that nearly all rifles are technically single action, the actions are defined more by mode, or operating mechanism ex. lever,gas piston, recoil, semi automatic, full automatic, delayed blowback, direct inpingement, controlled round feeding bolt action and so on

Sunray
June 15, 2007, 11:38 PM
"...open bolt versus a closed bolt..." Open bolt means the action is and must be open before firing. There is no cartridge in the chamber. When the trigger is pulled, the bolt is released to complete the chambering/firing sequence. The firing pin is sometimes machined into the bolt face, but not always. It's usually seen on blow back SMG's. There is one .22 rifle(French made Gevarm), that I've ever heard of, that fires from an open bolt.
A closed bolt is just that. The action is and must be closed before firing. The cartridge is already in the chamber.

JesseL
June 16, 2007, 12:02 AM
Someone should mention why rifles have single action mechanisms.

Rifle's almost always have single action triggers because they usually held to a higher standard of accuracy than handguns. A light, short, crisp, trigger pull is necessary for accurate shooting.

taliv
June 16, 2007, 12:24 AM
there are of course, lots of different classes trigger mechanisms in rifles. the two big ones are single and two-stage. there are set triggers, electronic triggers, straight pull, etc.

MachIVshooter
June 16, 2007, 12:41 AM
Someone should mention why rifles have single action mechanisms.

Rifle's almost always have single action triggers because they usually held to a higher standard of accuracy than handguns. A light, short, crisp, trigger pull is necessary for accurate shooting.

I don't even know where to start with this one...............:rolleyes:

(though I am now intrigued as to how one figures this logic applies to shotguns, which are also almost invariably single action).

hexidismal
June 16, 2007, 12:50 AM
I thought of one other DA long gun. Not a rifle but a shotgun. The very short lived Mossberg 590DA.

If you enjoyed reading about "Newbie question: trigger mechanisms" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!