[zackqw89]

Okay, I bought a NIB su-16c. Took it out to fire and used the stock 10rd mag and worked fine. Second mag i used was a Pmag 30 rd, Worked fine. Third was a Amend2 and had clearance issues(mag went to far into the gun and bolt would hit the back of the mag) not the main issue. also have a cheap 9$ 30rd mag and it actually did fine. after about 80 rounds i started having miss-feeds and stovepipes. Stovepipes would happen about 2 out of 10 rounds. Miss-feeds with the p-mag and aftermarket mag would happen almost constantly. the round would not chamber. To what i saw, It looks like the round hits the feed tube(whatever that thing is called that directs it to the chamber) and just stops. i have to push the charging hammer forward to get it to chamber a round. So after about 3 hours of fighting with this thing i was like the heck with this and went home. I look online for a few hours and found nothing. sent Kel-Tec a email and they told me to send it in.... (go figure) I decided to break it down and found out that the darn gas piston wont remove as you guys know, To remove the piston you pull forward and turn so that little square nipple thing is straight up. there is a tolerance issue and will not fit through the frame... Im about to throw this thing in the fire and melt it. so far this thing is completely worthless. ill add a few pics..any help would be appreciated. Thanks guys and gals

 

[Percevel]

Ok before you melt into to slag lets see if we can figure anything out.

I think breaking it down and cleaning, lube and make sure nothing is weird on the inside is a great idea.

The metal tab in the second picture does it protrude out past the edge of the plastic? In other words if you run your finger along the side of the plastic does the tab stick up enough for your finger to catch on it?

Also Those are some pretty strong looking scope clamps.

Would you mind to much if we took those off and see if that changes anything. That type of scope clamp may be incompatible with the polymer rail. I wonder if as you crank those down if they are deforming the polymer.

Maybe this became more of a problem when the rifle got hot from firing it.

 

[Percevel]

Also as for magazine. The only ones I have tried are Circle C mags. I have had no feed troubles at all.

However your problems do not sound like a brand of mag issue.

 

[zackqw89]

I can take off the scope and see what that does, and as for the tab, that is on the outside facing the rear. that tab is supposed to go through that opening and let the bolt assembly drop out the rear. i will see what happens after taking off the scope

 

[zackqw89]

oh, and to your question no. it does not. sorry. the i read that metal tab thing wrong haha..

 

[zackqw89]

okay, update: Took off the scope and the little metal tab made it through(thank goodness) SO! Thank you for that good sir. BUT! Im noticing the piston tube is very lose on around the spring. not crimped enough? or supposed to be like that? let me see if i can get a photo of what i mean

 

[zackqw89]

so here are the photos. as you can see, the tube is very loose. im not sure if that is supposed to be that way or not. i can actually spin that 360 degrees.

 

[Percevel]

So the ID of the piston tube is both larger the the piston rod. In the gas piston system the only place there is a fairly tight fit is the between the gas head and the gas block. The gas piston is a loose fit in the gas tube. and the gas head is also a pretty loose fir in the gas tube.

The fit between the gas piston and the end of the gas tube that has the tab has pretty tight tolerances.

You may wish to make sure that the gas piston is lubricated where it does through the small end of the gas tube.

 

[Percevel]

Spin the gas tube around the gas piston and gas head is no big deal. That is normal. In fact you have to be able to do that to push the pin out and separate the parts.

Could you take a picture of the bolt face. I am wondering if your extractor claw might be broken.

 

[Percevel]

So let me suggest a way to test your extractor claw. It might be easier to test the bolt if you remove it from the bolt carrier.

1. with the bolt carrier removed from rifle pull the bolt all the way forward.

2. Push the dust cover all the way forward so that it bumps into the bolt.

3. Gently bend the front of the dust cover up so it will clear the locking tabs on the bolt. Slide the dust cover a little more forward until you can see the firing pin retaining pin.

4. Push the firing pin retaining pin from right to left.

5. Remove firing pin.

6. Slide dust cover back.

7. push bolt back into the bolt carrier.

8. gently remove can pin.

9. remove bolt.

10. With bolt out rock in a spent case and see if the extractor claw will hold the cartridge with you supply a small side ways pressure on the case to depress the ejector spring. If the extractor claw hold with out popping off this may not be your problem.

11. While the bolt is out clean the firing pin hole. Also inspect the claw make sure it is not chipped.

 

[Percevel]

I would also suggest you consider using Militec-1 Lubricant. I have been using it for years on my rifles and pistols with very good results.

 

[Percevel]

Here is a video show how to test extractor
Check out at about 1:00 min
I realize that you have a SU16c and the video is discussing a AR15. however the operation of the bolt is very similar.
[ame]https://www.youtube.com/watch?v=kYm5UjojDMU[/ame]

 

[zackqw89]

The extractor claw is fine. it extracts fine and holds the rounds fine. now it seems like its a feed problem. like, when the bolt pushes the round into the barrel, it hits the guide and just stops. and i have to force it forward to chamber. could this just be a type of ammo issue? or a mag issue? im going to try it with the stock mag and see what happens...

 

[zackqw89]

okay, i tried it with the stock 10rd and i can tell its chambering just fine. I think the mags are causing all the issues now. So much for "Any ar mag will work"....

 

[Percevel]

Getting stove piped cases is often caused by weak extractor or ejector springs. I thought you mentioned stovepipe failures.

As for it getting stuck on the feed ramp... You feed ramps look about a grubby as mine do. However it may not hurt anything to get them cleaned up a little.

I am glad to hear that it is working with the stock mag. It should work with any mag. I just tried mine with a P-Mag and it actually worked better then with my Circle C.

Could you please take it apart again and measure the length of the gas piston spring please.

Thanks

 

[Percevel]

My spring is 10 1/8" long.

Your scope is still off right?

 

[zackqw89]

yeah my scope is still off. Do you mind if i measure the spring tomorrow? I have a few things to do before bed. The stovepipe going on might have been from being really dirty. I never cleaned it after i bought it and it sat in the closet for about a month before using it. I looked at the extractor though and saw no visible fractures or cracks or missing parts. doesn't look warped or anything. I will see what i can do for measuring tomorrow though.

.

 

[Percevel]

Spring strength is really important for both the extractor and the ejector.

Let me know if you have any questions or if I can help.

Good luck.