One piece receiver pin lockup??

[rybread]

I’m a huge proponent of the single piece receiver pins but I had one lock
Up today. What could cause this? Maybe my MAX11/15 pounding on it? Dirt? I have to hold the pin edge and hammer on the button to draw in the detents to pull the pin and remove the upper/ push the pin in and hammer the button to deploy the detents... wtf is causing this? In the AM I’ll try spraying it with some lubricant.

 

[Mackjack]

How old is it

 

[rybread]

Maybe 4 years- I’m going to soak it in lubricant and knock it around to see if it will loosen up. Something must have gotten jammed in there. I’m hoping I can make it work.. I just fixed my phone charger port, it was hard to get the plug in and it would fall out or stop charging- I turned it off and using a needle I dug out a huge amount of lint etc and now it works like new.

 

[Vegas SMG]

I had the same thing happen with two different single piece take down pins that I ordered at the the same time. Great idea, but I’m done using take down pins with any moving parts. Sometimes the simplest design is best.

 

[rybread]

So do they all fail like this? Was no testing done on these?

 

[HighriseATX]

I too had one fail / lock up on me. I was able to run the screw on the end and get it to retract the bearings. I just retired my last one of those and am using the one piece to Lage on all my MAC guns.

 

[timkel]

What pins are you talking about? Either of these?

 

[Vegas SMG]

Both of those picture are early originals Timkel, and both have their drawbacks. On the bottom one, I had to reinstall the latch tension spring in my original PS upper when I was using the one piece take down pin. I’ve now switched to using a two piece with no moving parts. I believe Strobro can share his experience with the other style of take down pin. Theres a thread on that style somewhere.

Here’s the take down pin we’re talking about.
https://www.knsprecisioninc.com/product/m11-push-button-take-down-pin/

 

[strobro32]

I personally like the KNS pins. I have 4. It requires better alignment of the receivers than a Lage pin or the 2 piece SWD pin. If you can slip a SWD or Lage pin through the receivers without effort, the KNS pin is much more resistant to coming loose, and requires no tool to remove.

I have never had a KNS pin seize up. I had 1 fall apart at the range. KNS sent me a replacement when I sent him a photo of the pieces. Great customer service.

I would contact KNS. See what he says.

 

[rybread]

Thanks guys I will follow up!

 

[opee]

I bought the same pin (link above) several months ago for my Max11-15. About half the time I have issues getting the pin to engage the bearings, .....it gets stuck with button pushed in.
Perhaps the pin has an issue? Maybe a little oil needed? Don’t want to pile on, but my expectation was much more optimistic when first ordered.

 

[rybread]

Haven’t gotten the old pin to free up but when I reached out, Todd at KNS dropped a new one in the mail for me- outstanding customer service! I’ll see how this one holds up!

 

[strobro32]

To remove the KNS pin use a thin blade flat head to unscrew the center pin. It should come apart. Then the pin slides out.

 

[Erehton]

I use the old PS slotted one and also the 2 piece design for my MPA upper that does not engage the slotted style pin. Part# 6A in the diagram below. The 2 piece design uses a fairly heavy piece of spring steel that cannot be moved without a tool, punch, key etc

http://www.cobray.com/smg-1-upper-receiver-details.aspx