I'm looking at a fine Dougall 16 bore double rifle with the lockfast action. The gun is in very good condition for it's vintage, but I can detect a slight amount of play indicating that it is off the face.

Given the eccentric cam-action in this mechanism, I would speculate that perhaps there is some adjustment that can be made, rather than using traditional methods employed to put other doubles back on face.

Does anyone have any expertise regarding this?

Also, any comments on the merits of the polygonal rifling found in this gun?

Cheers!

I will preface this post with the fact that I have never re-joined a lockfast action. From examining photos it appears that the eccentric cam pushes the barrels back against the breech face and locks them into the slot under the standing breech and the cylindrical protrusions of the breech face. It helps to smoke the parts together a try paper shims to determine the area of wear, I would suspect the cam and its mating surface. In times past Tig welding or piecing in a new bit of steel would have been done, today micro welding is likely the best bet.

Can you give more details on the polygon rifling? The Brits used a variety of systems to rifle a barrel.

Steve

Thanks for your comments, Steve.

With respect to the rifling, it appears to be very much like Whitworth rifling - a series of "hills and valleys" rather than lands and grooves. It's well described and illustrated at this Wiki site: https://en.wikipedia.org/wiki/Polygonal_rifling

I'm curious to know about anyone's experiences with this type of rifling in a bore rifle, like this Dougall.