AR Lower issues

[Zamble]

I just milled out my third lower last week. I took it Thursday and had it Type 3 anodized. I picked it up today and tried installing the new lpk. I installed the trigger, goes in fine. I install the hammer and I put the selector switch in and do a function check and the hammer will not release with the selector in any position but out.. I know the parts kit works fine, because I took it out of my first AR, its a 2 stage trigger. When

I installed a new lpk in my original and it fits and functions properly.

[Jeymz]

Possibly the trigger pin hole is out of spec (drilled too high) preventing it from pivoting high enough to release the sear. If you have a set of calipers measure the top of the trigger pin hole to the top of the receiver. Then compare that measurement with one of your "known good" lowers.

[Zamble]

In the trigger pin hole it measures 21.96mm to top in new one. And the original one it is 22,48mm.

[Zamble]

What can I do? I took it to a well known mill in NorCal. I spent $30 on engraving, $50 on type 3 anodizing, $80 to mill it and $150 for the lower. I don't want to have to scrap the thing.

[kcstott]

half a mm is not much but enough to cause problems.
I'd try to find someone to, One confirm that the hole is out of spec, And two if it is plug and redrill.

[Zamble]

The thing about plugging and re-drilling is that it is type 3 anodized, it would look like crap? Kind of a catch 22.

[Gunquester]

It is close enough that you may not have to scrap or redo the lower. It would be cheaper to play around with hammer/trigger. If I understand you right, the pin hole is about .5mm too high. The thing is it also might be forward of where it is supposed to be as well as high.

At any rate, look at how much the trigger is still on the hammer when you try and release. You could start sanding back on that part of the hammer and trying it until you can get it to work. I have not had your exact problem before, but I got an out of spec lower once and I had to work on the dis-connector to get it to function.

Another option is getting an adjustable trigger, which might have enough play built into it to compensate for the hole locations. Or you can see if a drop in would still fit despite the hole difference. Assuming the jig was tight, the holes should be the right distance apart, so with a drop in, the hammer hitting the pin .5mm higher would not be problem.

[Jeymz]

Unless you have some experience, I would not recommended messing with the trigger as you could compromise the functionality of your rifle. As mentioned above you could try another trigger that is adjustable or has a shorted pull. You may have enough room for it to function properly. Hopefully you know someone local that will let you borrow their trigger to test. Good luck.

[dmcmillenfv]

If the trigger hole is too high then the back of the trigger where it contacts the safety is contacting the safety before the trigger breaks. In that case grind down that side if the trigger allowing more rearward travel of the trigger, and or file the safety down, ( the flat section only) to allow more trigger movement.

[killmime1234]

It may be out of spec holes. The distance between the two holes can be correct while the holes are still incorrect in relation to the height and width difference. More likely it's a crappy LPK. I've seen good company's LPKs get worse and worse in quality over the past 6 months.

ETA: correction, I see that you milled your own. The more likely of my two answers is that you drilled the holes "off."

[McTac]

I see your in Nor Cal. If you would like to fed Ex it to us we have a few triggers around here and a Master Gunsmith to check it out for you.

[Zamble]

I see your in Nor Cal. If you would like to fed Ex it to us we have a few triggers around here and a Master Gunsmith to check it out for you.

Thanks you for the offer I really do appreciate it. But thanks the the miracle of the dremel, I was able to get it operational. I ground off about the half of a mm. The safety is still solid, so I did not take off too much. It took a while, though. I have a two stage trigger and it took a lot of grind reinstall every thing check, and repeat. The biggest problem I had was, I would slow pull the trigger and nothing. It wouldn't break. Then as I released the trigger it would break. It wasn't that nice crisp easy pull, ya know?

Thank you guys for the assistance. I must have installed the fcg 30 times? My finger tips are raw, lol. I started to get really frustrated when I busted the dremel out. I figured a safety switch is cheaper to mess with than the fcg.

[McTac]

Forget the lamp. I love Dremel!

Glad its working for ya

[Gunquester]

Glad to hear you got it. It would have sucked to lose out on all that work and money.

[ar15barrels]

What can I do? I took it to a well known mill in NorCal. I spent $30 on engraving, $50 on type 3 anodizing, $80 to mill it and $150 for the lower. I don't want to have to scrap the thing.

If the selector hole is too low, the trigger will not move upwards enough to release the hammer.
Remove metal from the top of the trigger where it touches the selector until the trigger travel is enough to release the hammer.