I picked up a Sionics NP3 bcg second hand and the gas key has minor damage around the gas tube interface. Do I need to replace the gas key or is it not a big deal? I checked it on my upper and it closes and didn’t appear to get caught up on anything.
Does it go fully into battery? Put it in the rifle and try it out. Shoot it. If you have no malfunction then you probably don’t need to worry.
Yikes, must have landed just right on a very hard surface.
If it was mine I would replace it, or at least try to bend it back to normal, for peace of mind.
Mark
The fourth law is that a dropped carrier will land on its gas key just as sure as toast lands butter side down. It’s a very common problem that can be fixed. If it’s not hanging up there’s no reason to worry about it.
What will happen is that your gas tube will start getting eaten away very slowly at the contact point. Too slow to notice most likely, but by the time you do notice, you will be swapping out your tube and key.
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What he said
This is why BCGs with integral gas key are some stupid shit. One of the things IG had his classes do was to strip down the BCG and install the carrier only and run it back and forth with your pinky finger to feel how the key was engagng the gas tube, it should be super smooth with no hang-ups, I’d bet performing that test you’d feel it. I’d replace the key, the screws with some OCKS and stake it with a MOACKS.
Yeah it might work for a while but I agree, best to replace it.
Replacement is not necessary.
HOWEVER -
It should be repaired:
That’s what I’d do.
What tool are these instructions for?
Key, Machine, P/N 12926769 (5313-01-310-0370)
Or, you can make your own, see Appendix E, page E-2, of TM 9-1005-249-23&P (dated 19 June 1991), available online, just google it.
(That Appendix has a few good tools, BTW.)
Could you use something like this?
https://cajungunworks.com/product/sp-forged-steel-starter-punch/
I forgot that i had this punch.
https://www.starrett.com/metrology/product-detail/264E
I’m going to see if I can fix it, but if not I’ll replace it. I had already planned to pick up a MOACKS from Ned at some point, just haven’t needed to yet.
That would probably work.
I personally would buy a small piece of delrin plastic rod and shape it to the key. A few taps with that won’t mar it and it’s strong enough to get it fixed
Either of those punches should work, as long as you don’t go crazy beating on the key.
Delrin? I doubt that’s not going to be hard enough.
That’s what I was thinking.
THANK YOU!!
I’d fish around in my garage/bench for something that matched the angle and just tap it back into shape.
Last night I stripped down the Sionics, an FCD, and a Hodge bcg and worked them back and forth in my upper. They all felt identical.
The center punch I linked has too steep of a taper and would open up the bore of the gas key tube before repairing the rim. But the blunt end of my other Starrett punches is almost the perfect fit. So I’m going to use the blunt end of my largest punch to try to gently tap it back it to form.
Thanks for all the assistance gentlemen.