I posted this over at Rimfire Central, but figured somewhere here might be able to shed some light as well.

I got this little beauty set up last weekend. It's incredibly accurate and a blast to shoot, but during the first 25 rounds or so, it will cycle but it won't reset the trigger. It came with 3 different recoil springs at varying spring rates. Currently I have the middle one installed. My question is this, do I need the lighter sping or the stiffer one? The weird thing is that after about 25 rounds the problem resolves itself and the gun functions flawlessley.

Can someone more knowledgable than I, please explain to me exactly what's going on and which spring I should try next.  Assuming of course that the recoil spring is the issue.

Thanks!

If the hammer won't reset, try the lighter spring.
Sometimes (with .22 ARs) a lighter or heavier disconnector spring is needed.

A lighter spring seems logical to me as well, but I swear that I read somewhere that the heavier spring was needed to resolve this particular problem.  I could just be dreaming that up though.  

Sometimes a lighter hammer spring.
WASR22 AKs need a heavier disconnector spring because the bolt bounces off the buffer fast enough that the disconnector doesn't catch the hammer.

Are you sure the bolt isn't cycling far enough back to lock the hammer back?

If the overtravel screw in the trigger is in too far it will not let the trigger reset properly after the first shot. If the internals get crud in them it can make the problem worse. Try backing out the overtravel screw a 1/2 turn and see if the problem goes away.

I seriously doubt the recoil spring is the culprit if it worked before. You could also chamfer the rear of the bolt to help with cycling but as I said I doubt that is the cause.

Dolomite

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I am not sure about anything on this gun.  The guy I bought all the parts off of offered to install them for me so I let him.  In hindsight I should have installed all the parts myself.  If I had, I would at least have some knowledge about it's inner-workings. The odd thing is that each time I've fired it, the problem clears up after about 25 rounds.  I'm kind of hoping the problem just goes away all together.   If it keeps up, I will eventually tear it down and investigate.  I just haven't had the time to mess with it and was hoping someone would know exactly what the problem was.

Thanks for the responses.