Safety selector won't install

[Rufus]

I am building another AR-15 lower, trying a impact ar timney trigger. I have that installed per instructions and safety selector will not go in with hammer back. I took one off selector off existing ar with milspec trigger and it won't work in new one. And new selector worked in milspec lower. I can't upload photo, but trigger assembly very slightly blocks safety selector hole. Anyone have this problem before?

[WARFAB]

It's been a while since I installed my RRA trigger, but I'm pretty sure I swapped in the new trigger with the safety still in place. I'm less familiar with the process for the cartridge type triggers, but I wonder if it will just slide in under the safety. The round end sections of the safety that ride in the sides of the receiver likely won't clear the tigger once it's in place.

[Rufus]

Will have to try that

[WARFAB]

Will have to try that

Did you ever find a resolution to the problem?

[Norm DeGuerre]

Hammer ...

[Rufus]

Backed out set screws, loosened tension screws, then I could get selector in. Tightened up screws reset set screws function tests seem to work. That should be the order of install or at least a trouble shooting option.

[Norm Deguerre x2]

Thanks for posting back

[Rufus]

Ran into a burr in the rear takedown detent hole, had to drill it out. It's a Anderson lower, I would say they might be a little to rough for a first time builder. Having previous experience, other lowers to swap parts to check, and this blog to ask for help kept this from being a nightmare. All done now and seems to function fine.

[big flash]

I had the same issue in my Anderson lower, same spot too! couldn't get that rear takedown detent in to the takedown pin without some work. Agree with this statement entirely rufus

[marquesgriffin]

I am building another AR-15 lower, trying a impact ar timney trigger. I have that installed per instructions and safety selector will not go in with hammer back. I took one off selector off existing ar with milspec trigger and it won't work in new one. And new selector worked in milspec lower. I can't upload photo, but trigger assembly very slightly blocks safety selector hole. Anyone have this problem before?

Seems like you've run into a tricky snag with that Timney trigger and the safety selector. If the selector won't slide in with the hammer back, it's probably because the trigger assembly's blocking the hole a bit. Since the new selector worked in another lower but not this one, there might be a slight difference in size between the two trigger assemblies. You could try comparing them or reaching out to Timney or some seasoned AR-15 folks for advice on how to sort it out.