Hammer wont fall when selector on Fire

Pretty sure the trigger/hammer holes or the Safety hole is slightly out of spec. Tried a few different safety selectors and all did the same. Just wont allow the trigger to pull far enough so the hammer will fall. I am thinking I could just file down the safety a bit, but not sure if it would affect anything else. I dont want to send back the lower for this.

Suggestions?

Is your PG screw too long?

Usually it is an out of whack disconnector holding the hammer back that causes these sorts of symptoms.

Remove pistol grip screw and try again. If passes test, shorten the screw so that it no longer touches the internals.

Also check the sides of the disconnector for rough spot/burrs. If its getting stuck in the trigger, it will not release the hammer.

Check for blown primer or such under trigger parts...

Thanks for the replies guys. Realizing now that I left a few key things out of the equation.

It was on a brand new lower build up, so that eliminates blown primer, etc.
I also tried it without the pistol grip/screw altogether, so its not an excessively long screw.
The trigger is a CMMG 2 Stage.
After looking at it some more, it really looks like the selector hole was just drilled slightly out of spec. Visually, it just looks like it to me because the trigger moves just a bit more so that it releases the hammer, when the selector is removed from the lower all together.
Could be something else, just seems like that is the case to me. Obviously, I am here to get advice from others.

ETA - Not really sure why, but I just dont think its an issue with the 2 stage. These have always been right on for me. Not 100% on that obviously.

Do you have another lower? Swap the FCG from another known good lower to pin down which component is the culprit!!!!
This is known as a differential diagnosis.
Cheers

I was hoping not to get this response

Wanted to keep from doing that, but I guess I may have to.

set up your lower so that you can drop the hammer safely. Remove the selector. pull the trigger while looking closely through the selector hole. If you have a little bit of interference you may just be able to lower the flat spot on the selector to allow the trigger movement. Try to measure that part of the trigger that's blocking the hole. Compare that to the flat on the selector. Or possibly remove some material on the lower part of the trigger that strikes against the selector.

If you don't have a spare lower, you could also do a differential diagnosis by trying a different FCG.

Have you checked to ensure the tail of the trigger isn't setting too high so when the selector is in fire, the trigger doesn't have enough travel to release. When I installed my RRA 2 stage I had to file down the selector slot (cheapest part) to allow full travel of the trigger. If that's your cause, procede slowly. If it fires with the selector out, you may have found your issue.

Bruce

This. You need to fit the safety selector where it contacts the tail of the trigger.

Not to hijack the thread but I'm currently building a lower as well with a Stag LPK with Doublestar lower. I notice when installing the safety selector there wasnt alot of clearance with the tail of the trigger. After both assemblies were installed I'm also having hammer issues. I'm currently in the middle of trying to see if this is the cause or not. My bet is we're in the same boat and the tail of the trigger assembly needs to be re-worked some. Hope you have some luck with it

I swapped triggers/lowers etc, and the problem was fixed

I guess it happens when parts are machine by different companies.

I would suggest you start another thread and describe these "hammer issues" before you try and "re-work" the trigger. I am sure someone here can help you out.

*File too far on the trigger and the safety wont work anymore.

Been there...

Jack...

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