I installed a Tapco G2 single hook trigger assembly on a Yugo underfolder built on a DCI 100% receiver.  When the hammer is cocked, bringing the bolt carrier rearwards causes it to come into a pretty firm contact with hammer, which it is able to push down.  If I gently let the carrier go forward, it will not go past the hammer, but if I let it fly it goes over it OK.

is this expected behavior, or do I perhaps have something installed improperly?  This beautiful gun shot 150 rounds with no issues 2 weekends ago, but I am wondering if I might have excess wear on the hammer eventually.

That is exactly how my G2 doublehook acts in my Romanian build. Flawless function so far and I just put a bit of lithium grease on the two so the wear will be minimal.

The G2's are notorious for having problems such as this with new builds.  If the rifle functions OK when actually firing, then I would just ensure that there is adequate lubrication and let it break itself in.

If you are having function problems, then I'd file a little off the hammer surface until the problem ends.  Others have posted here and on other sites about having to file a little off the hammer on the G2's occasionally.  I mention filing as opposed to grinding.  I myself do not wish to apply any heat or unnecessary friction on a critical part, so I choose filing instead.  I assume that the hammer is heat treated and am just using caution.  I don't know if it would really hurt to grind or not.

If it makes you feel any better - I have an Arsenal AK that hangs up on the hammer a little when I let it go slow.  But I've never had any problems with it functioning during firing.

Keep us posted.


DK

Polish your mating surfaces and apply some grease, lightly, to the mating surfaces. Also look at your rails and deburr if needed. I used a high temperature grease called Old Bull, it's an Industrial Grade grease used on plastic injection molds

I think that is common in quite a few AK's.  Even my Mak-90 with original chineese fcg, the bolt will hold up over the hammer if you gently let the bolt go forward, but it functions 100% when shooting and just letting the bolt go forward on its own.

Mine does the same thing.  It catches quite a bit on the top of the hammer.

My wum 1 did the same thing with original fcg.  Also with g2.  Also with another us made fcg.