Thompson Encore Forend issue

[mtnbkr]

I'm having an issue with bending the 8-40 screws on my TC Encore's forend.  This is happening due to recoil.  The chambering is 35whelen and the forend is a pillar bedded laminate forend.  It takes roughly 100-150 shots for the screws to bend and I have to repeatedly tighten them while shooting, maybe every 20 shots or so.  Those thin 8-40 screws only extend into the barrel 3/16", maybe a bit less.

I was thinking about one of the following solutions:
1.  Have a gunsmith drill/tap for larger screws, maybe a bit deeper as well.
2.  Using bedding compound to bed the area around the pillars to provide a broader, more tailored fit to the barrel. 
     This would increase the contact patch, but may reduce movement under recoil.
3.  Hanger Bar Modification.


Option 2 is my favorite as it's easy to undo if it doesn't work.  Option 1 seems logically better, but nobody else with the same issue seems to go this route.  Option 3 is frequently touted as a solution, but requires significant modification to the forend and will preclude its use on other barrels.  I'm not sure how well it would work with the already modified forend.

Thoughts?  Solutions?

Chris

[Triphammer]

I'm assuming standard 1018 steel screws? Try case hardening the screws. Easy, cheap if you have any CASENIT on hand. There's ways to Redneck it if you don't. Glass bedding may work but you probably want to get right up to the screw shank so there's no place for the screw to bend to.

[K Frame]

If you want to try this I have Casenit.

[mtnbkr]

I thought case hardening was a surface treatment and didn't affect the structural strength of the part.

I looked more into the hanger bar conversion, but that may be a no-go financially.  Besides preventing the forend from being used on barrels without a hanger bar (not a huge issue), it also costs $60 just to convert the existing forend (and $30 for the bar).  I'm still not sure if my pillar bedded forend could be converted.

I'm thinking glass bedding and maybe case hardening are my best choices in the short term.  If that doesn't work, then I can investigate drilling/tapping for larger screws (and screws that are available at the local HW store rather than specialty screws that must be ordered).

Chris

[K Frame]

It will provide some extra strength for the piece. Not as much as hardening and tempering, but it will help prevent the screw from bending. The hard outer layer resists the shear forces, while the softer core acts as something like a shock absorber.

[Triphammer]

I looked at a Contender/ Encore forum, a few folks there are talking about the much beefier screws threaded into dovetailed "receivers" for lack of a better word. Thoughts were running toward having the encore barrels dovetailed and buying Contender screws & receivers. The receivers sound like dovetail sight blanks drilled & tapped for screws. With a little time & care (and a safe side file) you could cut the dovetails by hand (I've done a few) & save the gunsmith costs.
Not owning either I don't know how the barrel diameters compare or if this would work in the real world but it sounded like the best solution.

[mtnbkr]

I used to own a Contender, so I'm familiar with what is being discussed.  I've never seen anyone make the conversion though.  It's another option to consider.

Chris