Yugo N Pap gas piston question

[jrs]

OK, I got an N pap from santa and after inspecting it, the gas piston is very loose. It's welded on both sides but seems to not be screwed in all the way?    It will wobble around but will not come off by hand. I've posted a pic of my O pap piston & it's flush fitted and spot welded only on one side. Can any of the AK gurus tell me if I need to contact CAI to fix this or is this normal? Thank in advance gentlemen.

Edit: The O PaP piston is the bottom picture. 

[Mancat]

Normal.

It's not welded, it's pinned in place, but the pin is only to keep it from threading out.

Some movement in the piston is desired to allow it to easily guide itself into the gas tube irrespective of the motion of the carrier.

[Mikeym_us]

Really? I know the OPAP gas piston is threaded all the way and pinned but the upper two pictures show the NPAP gas piston and that one has one heck of a gap in it. A little movement is ok a lot of slop isn't.

Normal.

It's not welded, it's pinned in place, but the pin is only to keep it from threading out.

Some movement in the piston is desired to allow it to easily guide itself into the gas tube irrespective of the motion of the carrier.

[AKBLUE]

The piston can vary a good bit on depth threaded into the carrier threads or amount of movement. It is simply sliding back and forth in the gas tube.  The AK gas system is very forgiving. Not an issue.

[Mancat]

The gap is not huge, pretty normal.

There were some problems with some Saigas coming into the US a few years back that had the piston threaded & press-divoted (Saigas don't use the pinning method) too tight - tight enough that there was no play in the piston at all, and cracked carrier stems were reported by quite a few people.

[jrs]

Thanks gentlemen, I appreciate the info.   Will the O pap carrier be OK since it's threaded all the way in with no play whatsoever?

[AKBLUE]

Thanks gentlemen, I appreciate the info.   Will the O pap carrier be OK since it's threaded all the way in with no play whatsoever?

Pistons tend to loosen up over time.  The only issue on a tight piston to carrier comes into play when there are canted or off axis components.  If the gas block or rear sight block or a twisted receiver or front trunnion off center the gas piston can bind or hang up or possibly crack the front of the carrier from the binding. 
As long as the firearm cycles smoothly and the carrier moves freely into the front components.,  it is fine.

[jrs]

Thank you gentlemen, I really appreciate all the excellent input. Only problem I have now is finding time for range time! 
Everyone have a safe and Happy New Year!!