Simple Screw but Hard To Find

[rhr1956]

I'm having a hard time finding a screw like this. I only need one. I'm almost positive it's a M4 thread. I can get about five full turns in smoothly in my thread checker but then it starts binding. Probably dirty threads. Do you know if this is some kind of unique screw? It holds the brass ram rod guides/holders that screw onto the underside of the barrel. See pictures for details. Thanks!

 

[Des52]

What gun? If CVA or Traditions Deer Creek Products has them.

 

[rhr1956]

What gun? If CVA or Traditions Deer Creek Products has them.

Italian made smooth bore 44 cal percussion rifle. Think it's from the 60's.

 

[Des52]

They may fit they are all metric. I would give them a call, they are really good to work with.