Bolt not locking back

All Things SUB-2000! After doing trigger upgrade , buffer recoil donut, recoiless charging handle the bolt doesn’t lock all the way back. About the width of buffer donut from locking back . Any suggestions? Thanks.

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Locking pin probably not seated

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I’m looking at the parts list and not finding locking pin. Is it also called something else or please disribe. I’m new to this, I appreciate your help.

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@Hawkeye1 The locking pin is not a Kel-Tec part, only Mcarbo. Check the installation video Chris has.

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@Hawkeye1

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Thanks. It wasn’t. Watched the wrong video. The locking pin I was sent was the one you screw in spring. Video I watched locking pin had a slot for screwdriver on one side and they put ptfe to hold it on and slide it in. One must be a older pin.

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None are screwed into the spring. Its still likely that it isnt fully seated into the charging handle.

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I watched a mcarbo video where it was. Go to recoiless charging handle on website. Under description, the video shows taking off black cap on spring and and putting locking pin in.

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New tool less integrated locking pin.

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Right. You still need the correct spring roation to get the pin into the handle.
Not trying to be difficult, but its the most common oversight when the bolt wont lock back.

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I’m having the same problem. Just a hair short of locking back. The pin is seating correctly. The spring internal rods are not in a bind. Everything is as it should be, but not locking. Any suggestions? Brand new, never fired. Maybe needs to to broken in? I’m scratching my head.

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I am in no position to second-guess your observations, but in almost every case of failure to lock back I have seen discussed on the forum the problem turned out to be an incorrectly seated pin. Beyond double checking that issue, I cannot help but perhaps someone else can.

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Easy way to check the tool-less pin engagement is to rotate your charging handle. If it rotates its not seated.
When you say brand new… is it an M-series?
Did it have the red recoil buffer donut (lifeSaver)?

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Finally got to shoot it. After about 30 rounds it would lock. Perhaps the recoil buffer nut was getting in a bind or something. I triple checked to make sure the pin was seating—audible click and spring and charging handle not rotating—still didn’t lock. Just needed to be shot.

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