SL9 issue +/- SS issue

ACWick

Hi,
I couldn't find anyone with a similar issue but I apologize if this has been addressed in prior posts:
My SL9 build (with metal SS) frequently freezes following a fired round: by "freezes" I mean the bolt remains open and the trigger and SS are "stuck" in place. The only remedy I have found is to force the front pin open (which takes some doing) at which point the bolt snaps shut and the rifle will fire again (once the pin is put back into proper position). This seems to happen regardless of whether the SS is in the single shot position or the SS position. Clearly something is binding together preventing the bolt from closing but I'm not sure how to trouble-shoot.

Also, and quite possibly related, I finally ground my buffer mass down enough for the SS to kind of work- the problem I'm having is there is not a positive "stop" for the SS in the middle position and the gun's recoil easily jiggles the SS to the right or left which obviously stops SS firing. (If anyone is interested I ground it to about 13.6mm which seemed to be the right dimension for the lever of the SS to stop grabbing the buffer mass). I generally can fire 2-4 rounds before the SS moves into either single shot mode or true safety mode.

Thanks in advance for Tim or anyone else's feedback.
AW

CCClinton

ACWick what upper and BCG are you using?

clifter1

Check out the instructions on Grey Market Research. They have a good trouble-shooting tutorial and this solved my issue with the bold binding open after firing a shot (last tip at the end of the article):

https://greymarketresearch.net/ar15-ar9-info-and-instructions/

ACWick

It's the Upper/BCG sold in the complete SL9 upper kit on HT- The BCG is stamped KAK but I don't see an identifier on the upper itself.
Thanks for the Grey Market Research link- I'll check it out.

Thanks!
AW

hoffmantactical

When you say it is shifting to the side, is that the cam or the lever? The SL-9 has a pocket designed to center the lever, so that should not be an issue. The cam is held in place by the detent track, regardless of the interactions of the lever.

The binding is usually due to the hammer cam surface pinching the tail of the lever against the OD of the upper. Grinding the top of the tail down a bit should fix it.

ACWick

Thanks for the reply,
To clarify, it is the cam that is shifting side-to-side into either true safe or single fire position. I suspect I do not have the detent retention screw screwed tightly enough (I don't have the weapon with me at present to check) but I recall I wanted to make sure I didn't over tighten/strip that screw, so likely my bad.

And by "grinding the top of the tail down", you mean grinding parallel to the flat upper surface of the tail to reduce its overall thickness, correct?

Thanks in advance for everyone's help.

undeadchew

ACWick
Next time you have a chance tighten up the safety detent and feel how much force it takes to move the safety button from side to side, it shouldn't be too easy to change positions otherwise yes it the cam can walk out of position.
I've filed down this surface on all of my purchased metal super safeties.

ACWick

undeadchew Great, thank you very much for your help!