[alcaviglia]

Found the notebook!

Firing pin retaining screw dimensions: 6-40, OAL (average between the two)= 0.175" = 4.45mm.

You may be having trouble due to wear. Most 6-40 plug are made to Thread Class 2A (as these are). If you can find a couple of Class 3A they will have larger minimum diameters across the board (by about a thou). That may help snug them up a bit. Just don't force them too much. Another solution would be to shorten the screw half a turn and turn the screw that extra distance so the slot sits a touch below the outside of the reciever. That may help keep it from working loose due to handling.

The Lewis that these photos, dimensions, etc... are from belongs to a neighbor of my parents. I worked on that gun for him a while ago. In response to the thread where you found the procedure for seating the hammers, I asked him to lend me the gun for a couple of days so as to snap photos and dimension things. Long story short, I don't have it in my possession.

I did a quick sketch and listed critical dimensions of the mainsprings, though. I can draft them up from that just fine. I was thinking yesterday of just offering to make them for you, but remembered that I let my buddy borrow my forge. I could only find 1 fire brick in my shop today and would need several more (to make a little oven) to harden springs of that size - a torch flame is just too small to do it evenly/properly. Of course, having the whole forge would be even better. I'll give him a call tomorrow to see what's going on there.

Most guys capable of making those springs will choose the right stock, but in case you want to give it a try: can't really go wrong using 1070 through 1095. But, you'd need something to use as an anvil or mandrel to get the radius correct, that being imperative as it's the crux of your shotgun's issue.

Anyway, I'll draft the springs regardless (I would need that, too) and send them to you. I can send it as a .pdf or even pop it into Microsoft Word, if you'd like.