While elongating the BB pivot might help, using the BB that came with a rifle. If you start with a new, water cut BB, you can fit it with contact to the frame but, the forces on the BB, try to rotate the BB down and away from the pivot, pushing it away from the contact area so, there is no direct resistance. The loads will be shared by both link and BB/frame contact. My guess is, because the contact, is on a angle (down and away), the link will still take most of the force.

If a RB type hammer is used, there is direct resistance. The wider contact area (full bb width) and larger pins, distribute the loads, over much a wider area, amounting to much better wear resistance.

The press fit pins, take out any impact wear, caused by clearance, between parts and would help prevent "creep" in the soft frame material (look up metal creep) and a heat treated BB and hammer would minimize it, on the contact surfaces between them.

I have two 44's (both 32/40) with a hammer lugs. the contact surface, is very small and the one that had been used more (newer one with "bolts"), makes contact but, the clearnance has open and does not hold the BB from moving, until the clearance has been taken up. HT surfaces would make that last longer but, there is not much contact surface, to begin with. 

I re-barreled it, in 32/20 and it stretched cases with 1300 fps, 180 gr loads. 30K by QL. I believe the RB type hammer would have kept that from happening in that pressure range. the rifle is now a breech seating 22RF, w/o issue, as would be expected.

Frank

uscra112 wrote on Aug 5^th, 2017 at 7:42pm:


With the RB type lock up (not hammer lug), the geometery can be set, so that there is a camming effect, as the two substanually larger surfaces, come together and in the last part of the travel, it can take up, all clearance, and still not have enough friction to stop it's movement.

This, of course, requires a high level of accuracy, fitting the parts but, with todays CNC machining, it wouldn't be a problem.

A problem with multiple links, is that they all have to have clearance to be able to move. Making links slightly longer helps take up clearance but, will add to the wear of each joint. 

Frank

more

wish I knew how to post all photos in one post.

now only missing a firing pin.....and bluing and checkering.

Since I opted for a take down model, I might as well make a carry case for it....here's a start

Very muggy yesterday so I stayed inside where I have some AC.....and did some checkering.