Hi, I’m aware that Franklin isn’t the best for PCC, but I have heard some people have had success with it. Anyone have any tips for making it run as reliably as possible? Different buffer/spring combo?  The upper and lower are both FM, 7inch side charge.  SBPDW brace. Thanks!

So I'm guessing here.......do you have a franklin armory BINARY TRIGGER installed  ??

And your upper/lower are FTM (foxtrot mike)  ??

Because if that's the case.... that trigger info is missing from your post.

Welcome to the forums!

From the context, it sounds like you are asking about a Franklin binary trigger, correct?

Binary triggers can be tough to get working in a PCC.  I had some success in a 9mm home build with +25% recoil spring (springco "red"), Brownells branded bolt, 7.5 oz. reciprocating weight buffer.

I never had any hammer follow, or "outrunning the trigger" issues, and it was very fast, but one day I discovered it would "binary" in semi mode if the trigger was released slowly. Tried different hammers, etc, but couldn't resolve the issue. That's a no-go in my book, so I got rid of it and put in an AIM SSTAT trigger instead. Still fast, but 100% reliable in my build.  Now I'm glad I did with the cost of ammo so high.

Be safe. If you get one, follow all testing/safety instructions in the directions. Follow all applicable laws.

I have a FM upper (8.5" side charging w/ Glock bolt) that works great semi-auto on a standard lower (using Endomags).  While I was waiting for my pistol lower to transfer I tried it on my buddy's registered M16 lower (w/ colt style mag block).  Worked fine in semi-auto, but on FA it turned into single shot.  With both my Glock cut bolt and his Colt bolt.  Think it may be related to bolt bounce...

Anyway, not sure on the difference between how a FA binary trigger works vs. a real deal M16 FCG  but I would first do all of your testing as regular semi-auto and once you know that is reliable then try going to binary mode.