Bolt action firing mechanism

[Flibby]

Okay I need your help with something guys.

I understand the basic principle of course of the bolt action rifle, but I need one of you gun nuts to tell me this detail!

In a mauser action rifle, the firing pin is 'cocked' by the rotation of the bolt. I need to know the exact principles behind this, for example....

How does the rotation of the bolt transfer into the rearward movement of the firing pin?

And what holds the rear of the firing spring in place, to enable tensioning of the spring?

And Finally, how does the spring remained cocked throughout the rearward movement of the bolt, and subsequent forward movement into position.

Thanks for any help into this

 

[Flibby]

Oh and a final thing, is this so for all bolt actions rifles, or are some cocked in other ways?

 

[Hoppy590]

How does the rotation of the bolt transfer into the rearward movement of the firing pin?

not all mauser type desings clock on close.

for say, a m1917/p14

theres a protrusion below the firing pin. that when the bolt is push closed ( but not turned) hits the sear and is no longer pushing on the bolt body. now when you turn the bolt down, the bolt body moves, with the lugs and all, but the pin stays stationary. and a grove lines up with the pins protrusion. when the trigger is pulled, the sear is tripped, the firing pin springs forward and fires the round. when the bolt is opened the protrusion rides the grove back to reset and rest against the bolt body....

do i make sense? il get some pics tonight.

 

[JesseL]

For cock-on-open actions, like you're asking about, there is a helical ramp built into the bolt body that engages the cocking piece attached to the rear of the firing pin. The cocking piece is stopped from rotating by a protrusion that rides in a groove at the bottom of the receiver and engages the sear. When the bolt is rotated the helical ramp pushes the cocking piece back and then holds it until the bolt is closed again. When the bolt is closed, the sear stops the cocking piece from riding forward again until the trigger is pulled.

This would be much simpler to describe with visual aids.

 

[Flibby]

That's great fellas, definately got a good idea about this now, but if anyone does know of any descriptive drawings or such then that would be fantastic, as the only pictures that I can find show either static blue-prints, or animations in a very basic sense!

Also I must apoligise for my terrible english, I am from Finland and it's not my native tounge

 

[Jubjub]

It's easier to see it than to describe it.



This picture shows the bottom side of a M98 bolt in uncocked, that is to say, fired position. In the rifle this would of course be in closed bolt position. The part of interest is the cocking piece, which is the part marked with a Z in a circle, as well as a bit of cat hair. This is the part that interlocks with and controls the firing pin. Notice that it has an angle on one side at the front, which matches up with the angle at the rear of the bolt body.



This is a picture of what happens as the bolt handle is raised. The cocking piece is being cammed to the rear.



This is the position of the cocking piece when the bolt is fully open. It has been moved all the way back to the cocked position.



This is the cocked, and ready to fire position. In the gun, the cocking piece and firing pin would be held back in this position by the sear, ready to fire.