I've had a 22LR upper for a while but had been hunting for the sear trip and bounce weight since the obummer days.  With kids and life it slipped my mind until I found both at a shop locally that matched the Spikes upper in the back of my safe that I nearly forgot about.  Got it out today and with federal garbage and CCI stingers I'm getting the hammer following the bolt but no second round ignition.  Trigger is dead, hammer on the firing pin, round chambered (most of the time 9/10 the exception is a fail to feel that mangles the bullet).  Semi function is fine with both ammo types, just not functioning when I swing into FA.  Please lend ideas to tune it.

Edit:  I'll post answers in the OP so not to bump needlessly and keep from having to read the entire post.

1.  Spike's factory upper with NI coating built in the early days when Tom was sleeping on the cot. He built it when I was there.

2.  Seat trip and bounce weight are Spikes with same coating. Both metal.

3.  Functions fine in semi with most ammo, goes to single shot when selector moved to F/A.

4.  I'm having issues finding the ball detent so will post pics of the bcg when I get home late today.

EDIT: 22:14 EST 9-11
I mirror polished the arms and bolt this evening after the kids and wife unit went to bed (no pics you dogs but chasb00b can tell you I married up, way up).  I also confirmed that I have the cut and drilling for the ball and spring adaptation but need a source or parts from Ace hardware to use that.  I will not be able to test until the weekend given the chaos of the kids and life, but please keep the ideas coming so I can run down a list Saturday or Sunday when I've mowed the hayfield that is my yard.

Edit: 10-14
First I'd like to give a HUGE Thank you to MTNWest.  He sent me a bag of ball detent & spring kits - he gets a beer or three if we're ever in the same AO.  That actually helped in semi with crap ammo but still getting the same error in FA.  I called and ordered a spring rebuild kit from Eric at Lakeside.  It should be here this week.  I also dug out of the parts bin both heavy and light hammer springs and will try both.  I appreciate everyone's input and patience in this thread.  Been a crazy fall.  Latest is the wife broke her arm so I'm saddled with sammich makin' and the vacuum rodeo

Are you using the metal weight or the plastic one? The plastic is just a forward assist adapter and will not work.

You are using a spikes kit? If you found a sear trip and antibounce weight at the LGS it is most likely cmmg spec. I believe I read that dimensionally they are not the same.  Timing could be off. Hopefully someone will come along with a definitive answer on that.

Tripping the sear early could cause that. Rides the bolt home. No energy left for firing pin strike. As mentioned above the weight acts as a dead blow to help mitigate bolt bounce. I fought that for months. Didn’t spikes come pre drilled for the ball detent mod? If not, google gorillas ball detent mod. I had to add it to a cmmg that suffered from bolt bounce. Works like a champ now.

Metal. And the parts were listed as spikes in a spikes labeled bag.

Also the ball detent mod - anyone have a thread where the pics are present?  I google-fu'd it and the archived threads here have expired pics and the 2 links to DIY's on other sites are dead.  Thank you - Chuck

My own personal experience has been that a "pressure plug" (for testing, I made a unit similar to the TACCOM product) or a “ball detent” should not ever be needed.  If a particular conversion unit or dedicated upper is not working reliably, something needs to be fixed, be it a dirty chamber, weak recoil or extractor spring, broken or bent part, undersized chamber, improper chamber lip, rough edges, tolerance stack up, out of spec part(s), issues with magazines, etc.  I acknowledge that the diagnosis of a given problem or set of problems can be difficult to perform with .22 LR, compared to 5.56 or even 9mm because of the numerous factors and parameters that are exacerbated by the .22 LR having small dimensions and relatively low power.

Just a couple of things to check out quickly are make sure that you bolt moves freely without a mag inserted, and then also doesn't drag on the mag lips with the mags inserted.  Any excessive drag on the bolt robs power and prevents the bolt from going fully forward (sort of a false bolt bounce).  Also, if the recoil spring is weak, it will not provide sufficient forward energy for the bolt to strip rounds off the mag and push the bolt fully forward.

Best of luck.

MHO, YMMV, etc.

ETA: Spelling correction.

Fostech sells a heavy recoil spring because their trip/trigger lock takes a bit of force to overcome.

Placing a spacer between your buffer and the rimfire kit will remove any slop, which will affect your timing.

FlChuck is a great guy!

But slicking up everything to mirror like surface, and running a lite oil is always step one.

never thought of that!!

And Chuck is your upper dedicated or a drop in kit?

If runs in semi right?

Yeah...below is my ghetto fix for that.  I just drilled/tapped an old buffer I wasn't using for a socket head screw so that it pushes on the kit forcing it forward.

There is alot of wisdom from Tom @ Spikes and others, I've seen the videos an have experienced the same, where 22LR kits have bolt bounce bad. Doesn't affect semi, but can ruin FA.

The options are - recoil spring, heavier anti-bounce weight, or ball detent (similar).

I did high speed video on my CMMG 22LR upper, bolt bounce is my culprit... the hammer hits and gets a light primer strike because the timing is such that it's mid bounce.

So, I can try the lakeside springs... will do, can add weight to the anti-bounce (will try that next), last will be the ball detent.

I honestly wish someone would make a new 22lr system, 2A did but it isn't FA compatible and may not be any better for FA. The geometry of the 22lR kit's bolt and collar leads to the crazy bolt bounce, I don't know the perfect geometry but a chamfer or something that two flat large surfaces smacking each other....

FYI...
Tom from Spike's input on tuning these kits:
https://www.ar15.com/forums/industry/ST-22-Semi-and-Full-Auto-Tuning-Guides/282-189717/?

Dedicated upper from Tom at spikes. Runs fine semi with most ammo and black dog mags.

what is the timing like? you can check it with a 5/64 drill bit.

If thats good, then you have bolt bounce common for 22lr.
heavy recoil spring or the ball dent mod.

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Another thought, as the barrel and collar (as well as trip and anti bounce weight) are probably good, why not relegate the bolt/recoil assembly to semi auto only use or sell them as such and just buy new parts from a current vendor?

In any case, best of luck.

MHO, YMMV, etc.

that is one way

thanks man

Unfortunately, there is no other vendor. Spikes quit producing .22 conversions years ago - very difficult to find one modded for ball/detent.  To my knowledge, neither Ceiner or CMMG ever produced a ball and detent .22 lr conversion.

I could mill that..

The Spikes Tactical .22 conversion that I bought years ago had the hole and notch for the ball detent, and came with the ball and spring in a poly bag.  I never installed them.

You can also add the original vendor, M.A.C., and Target Master to the list of vendors who have sold AR .22 conversions that, to the best of my knowledge, do not include "ball detent" accommodation.  That should tell you something.  You may recall that up thread I indicated that I do not feel that a spacer/pressure plug or a ball detent should ever be needed.  Apparently at least four AR .22 conversion vendors who together have sold many thousands of AR .22 conversions feel the same way.

I do not ordinarily make the suggestion for one to consider giving up on a .22 AR conversion full auto operational issue.  However, keep in mind that when Spikes Tactical left the .22 conversion business, IIRC, the reason stated was that their subcontractors were not supplying in spec parts.  That makes trouble shooting problematic to the point where it may not be worthwhile.

I wish you the best of luck, whatever you decide to pursue.

MHO, YMMV, etc.

2A

because 99% of their market is semi, that's why it's simple math.

2A released a 22 kit, redesigned from the ground up - not a thought or accommodation for FA at all.

Even when I engage CMMG Tech Support, they always reply they weren't designed for FA and it may or may not work.

The detent has proven effective at reducing bolt bounce, which causes many FA 22 ARs to fail.  It's utterly useless for SA. Not sure why anyone has anything against it.

Go in order of easiest to hardest if you have Bolt Bounce in FA...  Recoil Spring (Lakeside), Add Mass to Anti-Bounce, Ball Detent Mod.

Let's face it... if we're being indignant about less than ideal solutions.... then we ought to settle for nothing other than geometry changes to the bolt face, the real culprit to the obnoxious bolt bounce in these kits.

The first cmmg kit I picked up ran great. The second was a pain to get running reliably. Recoil and extractor springs as well as a pressure plug from taccom. A spring kit from Lakeside. All helped to some extent. The issue I continued to have was each spring tweak made it more reliable but with only one specific ammo type.

With the ball detent mod. I run cci suppressor, SV, mini mags etc. actually I have found only a single ammo that didn’t work. Quiets being the lone exception. I was unwilling to change the SSF hammer spring out in an attempt to get them to work.

Well damn. Never thought to check the original post. I have a bag full of ball bearings and an extra spring. Just cut to size. I cannot promise they are sized to work. I had to mill my own but they should work for you. Send me a message and I’ll send them to you if you can’t source them. McMaster Carr had everything I needed.

i had similar issues and ended up not requiring antibounce or ball detent mod. strange but true.

heavier recoil spring was huge and resolved 90% of the f2f issue, ie bolt bounce

i lightened the trigger spring, ie bent the legs back, so it would reset the trigger with less energy

the last issue was mags. black dogs are all i have anymore

eta: the member circuits is very educated on this and could provide insight

Update for my own setup... after almost 2 years of having the CMMG kit, I finally got it running FA.  Not to say I've toiled on it daily, out of frustration, lack of time, etc I didn't touch it for months at a time.

I was suffering light primer strikes, suspected due to bolt bounce. What I never had was issues with the system not cycling in Semi, etc - so I didn't need lighter hammer springs or other things along those lines.

In the beginning, I ordered the reliability kits available - better firing pin, extractor, extension block to hold the system forward, etc. That remains in place.

I replaced the spring from this kit with the even heavier lakeside spring I got from gunbroker.

Still did not run.

Decided to do the ball detent mod. Still light primer strike on second round. not early sear trip, it's very late on purpose. Hoping the ball detent removed any bolt bounce, as it is very hard at this point to even manually charge so it is locking up really good.

So... I guess FCG.... and I replace a standard M16 FCG that I had in there with a POF M16 drop in FCG I had and boom... starts running like a top. I am guessing the hammer spring??

I take out the ball detent to see if it is even needed - won't run without it, so it needed at least the different FCG and the ball detent.

I haven't backed off the lakeside or other changes... as long as it runs will keep it this way. I did order an extra power hammer spring that I will later try with my standard M16 FCG.

If you are getting light primer strikes on the 2nd round: Try a different FCG / heavier hammer spring

I still needed the ball detent... but I haven't read the above called out anywhere in my research so something to consider....

My Spikes required running hot ammo (mini mags) to cock the hammer and extra power recoils springs (Lakeside) to push the bolt all the way back into battery.

This was using a Lakeside reduced power hammer spring.

Your expiernce seems to be the typical experience. You ever have light primer strikes on FA runs? I still do. I am going to an even heavier hammer spring.

However, mine runs garbage ammo well now. Even with heavy lakeside recoil spring and a super stiff ball detent and heavier hammer spring.