A friend of mine brought over an I.O. AK-47 that he purchased new a couple of years ago.  It occasionally doubled or tripled, so he sent it back to I.O.
They returned it, still doing the same thing.  He sent it back again, they returned it, again, still the same problem.
He picked up a Tapco G2 double hook trigger group and it sat in the safe for a couple of years.  This weekend he brought it over since I was already putting together an AR for him.
I installed the G2 for him, but test cycling it the hammer follows the bolt, never hooks.  I can lock it back manually.

Any ideas?

Thanks,
John

I’d get my money back or threaten to report IO for manufacturing a machine gun. If I was you I’d get your hands off it and delete your post.

It no longer doubles, now it doesn't fire at all.   It won't cock the hammer.  So it's a paperweight not a machine gun.  I'm trying to figure out how to turn it back into a rifle.

John

Got it.  http://www.nodakspud.com/troubleshooting.htm

It’s entirely possible that the pin hole dimensions in the receiver are out of spec.

A potential remedy (besides getting a new receiver) would be to try a Red Star Arms FCG. The adjustability they have might be enough t9 get your rifle shooting.

AJ

This is a common issue when swapping fire control groups on AK’s. What is happening here is that the hammer is not being captured by the disconnector when the bolt carrier lays it back. A simple fix to this would be to simply take a file to the ear on the hammer that the disconnector grabs and shave a little off until it finally snaps under the disconnector when you bring the assembled rifles bolt carrier back. Then shave a bit more for luck. Probably won’t need more than a few drags of the file. I would not recommend dumping anything into the IO that costs more than the tapco. They simply are not worth putting the money into. After a few thousand rounds you will need to take a look at the disconnector and trigger pin sleeve. I have seen these wear through due to lack of lubrication.

I've read that it's totally normal for many AKs to double fire; if shooting prone or from a bench.( For accuracy) Supposedly if you lightly squeeze the trigger, it has a tendency to bump fire.

Is there any truth to this?

No.

There is a reason a ton of those rifles were disassembled into parts kits... They had badly out of spec receivers, and many of the essential components (bolt, trunnion, etc) were made poorly and simply could not work together when assembled.