Aero lower w/ Geissele SSA hammer not dropping freely

[Roneski]

So I got a decent deal on a stripped Aero Precision lower. I got it put together easily enough, but I notice that with the Geissele SSA I picked up for it, the hammer doesn't fall freely, there is some definite resistance. I tried dropping in an old single stage that I had sitting around and it seems to work fine.

I cycled it a bit to see if it would loosen up. It did slightly but there is a some wear on the inside of the receiver approximately where the springs would coil on the hammer (about a millimeter outside of the pin hole). So is the problem the trigger, the receiver, or me?

[Col_Crocs]

Did you have trouble fitting the hammer into the receiver pocket to begin with? Was it tight on assembly?
From what I understand, your hammer spring fits too tight between the receiver wall and the hammer, causing it to snag.
I would ensure everything is installed correctly(the hammer spring in particular) and try again. Since youve already tried another trigger on your AP lower, it would also be a good idea to try the SSA trigger set on another lower.

[Roneski]

I was pulling the trigger out to test it in another lower when I noticed a bit of brown goo that the grease I had applied to the trigger seemed to be breaking up. I took some solvent and a brush to the trigger and got a bit more of the brown stuff off. I'm not sure if it was really weird packing grease or some finishing byproduct, but after reinstalling everything seems to run fine.

Guess I should have looked closer at the trigger before installing.

Thanks for the reply!

[Col_Crocs]

Slight rust? :confused: Glad youre GTG.

[Roneski]

Rust was my first thought too but I gave it a pretty serious scrubbing and never found any bare metal. This trigger was finished a little differently than the last Geissele I picked up, it had "Geissele" printed on the hammer.