Cam pin question

[fstdraw]

Doing a good cleaning on my 7.62x39 AR. I notice the cam pin won't spin freely in the bolt. It really took a pair of needle nose pliers to turn it to remove it after I lubed it.

Should the cam pin slide it's full length thru the bolt? If not, should I just file it a bit until it fits and spins freely? It's a Bear Creek upper and has worked flawlessly so far, about 300 rounds.

Thank you.

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[Pepe-lepew]

The bolt is peened on the opposite side so the cam pin can not be inserted if the bolt is upside down. Therefore the cam pin will not slide freely through the bolt or from both sides of the bolt.

Cam pins wear. They may build up an edge if severely worn. Replace them periodically if you question if they are still serviceable.

 

[fstdraw]

Gotcha, and Thank you!

 

[msgriff]

Are you talking about the cam pin not being able to rotate in the bolt with the bolt removed from the carrier?

 

[ma96782]

LOL. I was gonna say.....that once the BCG is out of the upper receiver. You should at least remove the cotter pin and firing pin BEFORE attempting to remove the cam pin.

OK, Ok, ok.......yes that was a sort of JOKE.

Anyway. IMHO.....check for congealed oils and dirt too. One could also use a bore brush to help with cleaning. IF.......I was desperate, I might try a bit of "sanding". Or I might just use a spare part.

Don't have any?

Well, now you know why people keep spares.

Really.....those "spare parts kits" do come in handy. And they don't cost all that much (in the big scheme of things). Especially, when you're searching for that "lost" detent spring that went flying across the room over a half hour ago.

Aloha, Mark

 

[fstdraw]

LOL, yes spare parts would be a help in this case. I just used a diamond file and removed a burr. I'll be getting some spares!

 

[Dr Prepper]

LOL. I was gonna say.....that once the BCG is out of the upper receiver. You should at least remove the cotter pin and firing pin BEFORE attempting to remove the cam pin.

OK, Ok, ok.......yes that was a sort of JOKE.

Anyway. IMHO.....check for congealed oils and dirt too. One could also use a bore brush to help with cleaning. IF.......I was desperate, I might try a bit of "sanding". Or I might just use a spare part.

Don't have any?

Well, now you know why people keep spares.

Really.....those "spare parts kits" do come in handy. And they don't cost all that much (in the big scheme of things). Especially, when you're searching for that "lost" detent spring that went flying across the room over a half hour ago.

Aloha, Mark

Please dont sand it, use fine steel wool. I'f some minor deburring is needed maybe crocus cloth sandpaper ei VERY fine sandpaper.

Also a caveat some makers like Aero's new pro BCG isn't swaging the hole anymore it weakens the already thin metal there. Also they should reduce the diameter of the can pin hole to make the bolt stronger.

Check your CARRIER for burs and defects in the slot/channel it may be repeatedly slamming a defect into the cam pin. Also I mark my cam pins so they are always installed the same direction (forward) every time. You shouldn't really spin them around or they will wear out faster.
Larue makes a really nice bolt cleaner/scraper.
BCA really doesn't make the nicest stuff, its pretty bottom rung. That being said, I have a BCA side charging upper that's still new and haven't shot several years later but the BCG AND upper were only $100 total. So I won't complain regardless of what happens

And yeah, like Mark points out I'd keep at least one extra can pin handy for a backup, those spare parts kits are like $12-15 bucks. Money def. Well spent.

 

[Dr Prepper]

Oh also, ESPECIALLY if its a piston upper. Those things are easily 2-3x more hard on your bolt than the standard gas system since there no real delay I'm unlocking and the piston literally just hammers to BCG rearward. I say this since you mentioned 7.62x39.

 

[ma96782]

RE : Post #7

IMHO.....
Yes. The grit # of your "sandpaper" matters.

And LOL.....this is NOT a job for the belt sander.

Then, as for using a "file".
Well maybe, that might just be a little too much. As in, maybe the file might be introducing a stress-inducing "scratch" to your part. BUT, But, but.......I wouldn't rule it out entirely.

That spirit of Wile E. Coyote Gunsmithing lives!



Anyway.......whatever......be careful.
You be the judge, of how much you are/would be willing to "work on it".

All while.....the abundance of caution (new replacement part) approach works too.

Aloha, Mark

 

[fstdraw]

I'm convinced, several replacement parts are in this weeks future!