doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com How does a greener cross bolt work?

Can anyone provide me with a description, or a diagram of how a greener cross bolt operates? I understand the basic function, but I'm curious to see how it is connected to things on the inside.

I see that no one has responded to your question yet, so I will take a stab at it. I had a Francotte with a Greener cross bolt, and the top lever had a flat wedge shaped projection (with the large end toward the front) on its front edge that went under the top of the standing breech just to the left of the rib extension, and fit into a longitudinal slot cut into the back of the cross bolt.

Pushing the top lever to the right forced the left edge of that projection against the left end of the slot in the bolt, pushing the bolt out the left side of the standing breech. When released the top lever return spring forced the right side of the projection against the right end of the slot, moving it back into the locked position. In my gun there was no separate spring or any other parts, the bolt depended on the top lever spring for tension.

I once saw an illustrated parts list for an older Bernadelli Gamecock gun (maybe in a 1960s vintage Shooter Bible?) that showed the top lever with its projection, that visual might help you understand how it works. Unfortunately, I no longer have that Francotte to take photos of.

In hand it seems very simple, but I suspect that the shape of that projection and the length of the slot are critical for it to work properly.

Not a great shot, but this is some Greener lever work with the stock removed which may help you visualize redoak's explanation somewhat:

I am surprised you are not getting your answer from the other active thread on BOLTING.

The one I have on a Birmingham trade gun is pretty straight forward. The top lever has a small leg at the front which goes into a slot in the cross bolt. It's all hidden just off centre of the top of the breach. When the lever is moved to the right, to open the gun, the leg at the front of the opening lever pushes the cross bolt to the left and clear of the hole in the rib extension that sits in the slot between the fences at the top of the action so the barrels are free to open, some of the cross bolts stick out of the side of the fence when open, others are hidden inside. There are also different mechanisms for operating them, some fancy, some not so fancy. Whether or not they really contribute to the strength of the lock up is open to argument, many different styles have been advertised as the best and strongest yet over the years but it's know that many were over complicated or offered no real advantage .
I believe the trick when fitting them is to only allow the bolt to fit against one side of the hole in the extension but can't remember where I heard it.
I hope someone with the know how may add to that as I'm not sure what I've written will make sense now I've looked through it

edit, sorry Redoak, didn't read your post before I scribbled mine down.
I've altered my post too after noticing a mistake.

http://www.vintageguns.co.uk/articles/366-2/

this may be of more help.

Greener Crossbolt - A tapered round bar, operated by the toplever of a shotgun, passing transversely behind the standing breech of a side-by-side gun and through a matching hole in a rib extension; to strengthen the lock-up.

Greener Crossbolt - A slightly-tapered round bar, operated by the opening lever of a break-open side-by-side gun, passing transversely through the standing breech and a matching hole in a rib extension; to strengthen the lock-up.

Scott's crossbolt operates similarly, but is square in cross-section.

A Kersten Lock operates on the same mechanical principle, but is more suitable for over/under or single shot guns.





The above is from http://www.hallowellco.com/abbrevia.htm#G

Pete

Thanks a lot for the help, I've been looking for a clear explanation for a while, and have come up short until now. I figured the best way to get a conclusive answer would be to ask some people who own guns with a greener cross-bolt, clearly a very good decision. Thanks a bunch.

I have never owned a Greener so can't speak for the "Original" but on other makes I have owned which used a crossbolt they did not appear tapered, though I never actually measured one of them.
In the D M Lefever catalog on his New Lefever which used a crossbolt he did state hs bolt was tapered. He also used a stop screw on the right side to prevent the bolt from sticking.
When used in conjunction with an underbolt the crossbolt's primary purpose it to resist the springing of the frame.
In the case of the New Lefever only the crossbolt was used so it served the dual purpose of both holing the barrels shut & resisting frame springing.

Didn't one of the writers in the Edwardian era pontificate that the bolt HAD to be square for the best bite?
I was thinking Greener himself, but, it was half a lifetime ago that I read his book....


Best,
Ted