KP-05 cycling problem: questions

[Jimski]

hello all
my CO2 KP-05 (the para-ordnance from KJWorks) is starting to have problems cycling.At first I thought it was mag-related but apparently it randomly does it on all mags.
I noticed
-the chamber movement is a bit weird, like it always lack of lubrification, even when lubed.Could it be a cause?
-when I push on the bottom of the magazine it gets much better.what could cause this?

-could the hop rubber be related to that?
other than that the gun seems to be in good condition...

any ideas?
thanks for your help.

[Spawn28]

A worn mag catch possibly causing a misalignment of the internal moving parts?

[m102404]

If holding up the mag results in "perfect" action...then you're looking to the source of the issue that's causing a less than perfect seal between the top seal of the mag and the blow back nozzle.

1. Worn mag catch...allows mag to drop/sit lower
2. (Hicapa/ParaOrd specific)...grip screws to midframe, grip screws can loosen/grip holes can open up....resulting in the grip not sitting tight with the mid frame
3. Slide wears in and gets loose...causing the whole top assembly to ride inconsistently.

Just a little bit off with all those factors can add up to a noticeable effect.

1 & 2 can be resoved with new parts....3 is not usually fixable. Less of an issue where the nozzle interface and top seal are ramped to "jam fit" together...but the Hicapa setup is pretty flat.

You can also try some mods that attempt to get a better seal...but there's mixed results and they can cause more headaches than not:
1. Put a shim layer under the top seal rubber (i.e. cut out a plastic shim from thin plastic sheet...like a pop bottle). This raises the top seal a bit.
2. Put a shim layer between the top of blow back unit and the inside of the slide. This forces the BBU down a bit. Can also cause feeding issues.
3. Play around with the tightness/angle of the BBU when the rear screw is tightened up...on some tightening up the screw will torque the BBU out of line

[Jimski]

thank you very much!
so apparently it's not the mag catch, I come to believe it's the chamber operation that sucks, it often stay stuck opened. will lube...