View Full Version : Can't strip Armalite AR10 BCG!
wild_wild_wes
02-16-13, 22:28
I was trying to disassemble my new Armalite AR10 BCG today, and the cam pin hits the carrier gas key and can't be pulled out all the way. Any ideas?
Remove the firming pin retaining cotter pin,than remove the firing pin
And rotate the cam 90 degrees and remove.
Drunk Post.
Never seen that. Did rotate it? Pretty sure they didn't assemble gas key after....
FYI the Armalite AR10 can get it's bolt stuck in the carrier. DO NOT push bolt backward after removing cam. The chamber widens, gas rings pop into it.. stuck.
Does the gas key look like it is obscuring the top edge of the [rotated] cam pin when viewed from directly overhead? More than likely it is not, therefore try wiggling the cam pin or light prying pressure with a flat-head screwdriver. I have had mk11 and m110 cam pins do the same thing. The key would cause the cam pin to bind just enough that fingers alone weren't enough to pull it past the key's edge.
wild_wild_wes
02-16-13, 23:16
I've just been using finger pressure. I'll try a flathed to try to get more leverage, but its pretty damn tight.
We just had an LWRC cam pin in my class this weekend that wouldn't come loose. I had to use a flat tip and pry up out of the cam pin slot.
wild_wild_wes
02-17-13, 02:00
The cam pin is loose. But before it can be fully extracted, it comes in contact with the gas key and can't be pushed out past it. I haven't tried forcing it with a tool yet.
Exact same issue. We had to move it a little as we were doing it unless there is something out of spec or totally unique about it.
The cam pin is loose. But before it can be fully extracted, it comes in contact with the gas key and can't be pushed out past it. I haven't tried forcing it with a tool yet.
The_Hammer_Man
02-17-13, 03:39
The cam pin is loose. But before it can be fully extracted, it comes in contact with the gas key and can't be pushed out past it. I haven't tried forcing it with a tool yet.
Did you turn it clockwise or counter? Had this exact issue with a friends AR-10. Turn the cam clockwise.. no go.. turn it counter clockwise and it would come out.
Really tight tolerances.
If it's still stuck give it a tap with the handle of a screw driver then give it a gentle lift. This a brand new BCG?
I have seen a few cam pins that were difficult to remove from the BCG on new AR-10 rifles. A screwdriver was needed to remove them. After a few thousands rounds they were easier to remove.
Strange - have never seen this on Armalite BCGs. I had mine NiB coated without pre-tolerencing and it's perfectly fine in the cam area. Must be a range of inconsistency with them.
Read step 7 on page 36 of the owner's manual concerning removal of the cam pin.
http://www.armalite.com/images/Manuals/AR10Manual2.pdf
I have one that does the same thing.
It's not an operator issue, the gas key doesn't have enough clearance for the cam pin to pass in any orientation (or the cam pin head is too large, I don't know). I'm going to grind the side of the gas key to allow it to pass, but I haven't gotten around to it yet.
Pretty lame, but not a showstopper.
I would grind on cam key before gas tube
caelumatra
02-17-13, 12:04
I have one also and it does the same thing. It will come out thought. It wont come out with fingers for anything. But I use the blunt edge of a knife and lift it and it comes right out. Its real strange. Almost like I'm slightly twisting or something so minor I'm unaware I'm doing it but using a flat tool works with no problem.
I'm not saying I'm forcing it out just using the smallest amount of leverage with a flat edge and it comes out as it should.
wild_wild_wes
02-17-13, 12:29
I would grind on cam key before gas tube
Read step 7 on page 36 of the owner's manual concerning removal of the cam pin.
http://www.armalite.com/images/Manuals/AR10Manual2.pdf
7.Lift out the cam pin (BC-4).
NOTE: Until parts are broken in, tight tolerances sometimes require use of a flat tipped screwdriver or other suitable object to gently pry the cam pin past the bolt carrier key. The cam pin must never be altered to provide clearance.
The external portion of the cam key has little to do with function. Be it round, square, oblong or roller type.
I would hope all manufacturers advise against altering any portion, esp internal parts, of their wares.. as most customers have little idea of how the magic boom-stick works.
If you are going to alter something, start with the cheapest, least important, easiest to replace part. And maybe not a part which is getting over 50,000psi pushed through it.
I have had 2 .308 AR's in the DPMS LR-308/Mega MA-Ten pattern whose carrier and cam pin were exactly like this. Nothing wrong with them, just that the tolerance between the key and cam pin was so tight that you had to push the pin out. After a hundred rounds it slid out via gravity.
The tightness isn't where the cam pin passes through the bolt and carrier, it's a clearance issue between the carrier key and the cam pin head. Since the head of the cam pin doesn't rub against anything (and neither does that part of the gas key), I'm not sure what magic is going to happen to make these fit together (unless the hole the cam pin lives in opens up, or the diameter of the cam pin wears down).... but I really hope those won't wear that fast.
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