My first AR build. 

 

Have a PSA lower with lower parts kit

PSA premium bolt carrier group ( chrome lined, MPI)

PSA premium upper ( chrome lined, blah blah)

milspec buffer tube assembly 

 

 

My problem comes with the clearances inside the upper. I bought a cheap-ish charging handle that I suspect is out of spec. Please let me know if you agree or possible troubleshooting to determine other issues. 

 

But the action is extremely hard to cycle and the bolt will get stuck to the rear, with the CH needing a bump and the bcg will slam home. 

 

I broke it down and removed the buffer and spring and was able to pull the bolt back with difficulty, not a substantial change from with the buffer/spring in place.. 

 

Attempted 4 times total and the results are in the pictures. 

You don't happen to have another charging handle to test with, do you? About 18 months ago, we sourced some charging handles that turned out to be out of spec and caused the same malfunction you're describing.

Unfortunately I don't have another CH on hand. I suspected it was a semi-common issue with the number manufacturers. 

Did the issue seem to be verbatim or something to this effect?

 

Nickjc

 

would you happen to know the height of the CH catch ?

Should be about .300-.302 (measured a few I have in the parts bin). The failures experienced with our out of spec batch had the handle binding up about 1/3 of the way through the travel as it was being pulled back. I can't speak to what exactly was out of spec as we just junked them once the issue was uncovered.

going to grab a caliper on the way home and check it out. 

 

For shits and giggles, if the handle is in spec and being you both have more experience than I do. Anything I should check next?

Is it straight? As in REALLY straight?

Is it straight? As in REALLY straight?

The CH? or something else?

Where are you located? Maybe another member can meet up with you and lend you a charging handle. If you are near Woodbridge or East Brunswick, i can pull one from one of my AR's and bring it along just to try it out real quick.
And i'd assume he meant the charging handle.. If it's bent its no good, lol.

The CH? or something else?

 

The charging handle. I've see some bent over the years due to abuse, but I suppose they could be that way from the factory too.

It looks straight but I can double check.

 

I'm in the Blackwood area in southern Nj. 

If you don't hookup with someone before then, come to SJSC Sunday morning

I'll be there for a 100yd hi power team match on the 300yd range

0800 setup till before noon finish

Look for the "Black Guns Matter" hat!

ha, I'm a member there. I may just do that. If a guy that looks like your typical depiction of Jesus walks up to you that'd be me.

 

But I think I found the issue thank to your measurements and a set of calipers. 

 

The handle is within spec except for the width at .389 and the front lug height .598. Having said that, there looks like a burr on the crown of the CH.. I may shave that off with a jewelers file. But not until I hear back from the company that sent the CH. To preface it so I don't sound like a caveman ready to fix it myself. The crown looks pointed, not flat. It may just be a glob of the coating, I can't tell. 

Crazy how precise such a primitive, basic piece of metal such as a charging handle had to be for it to function properly as a whole, haha.