newer style 80% spec question

[savs2k]

Oh man... I was doing a older style 80 last week and wrecked the takedown pin from a snapped drill. I decided to start over with the newer style 80% with a solid pocket. However this being my first one with a solid pocket,I thought it was way easier then the other style and didn't know there was a spec to put the top adapter plate on. After doing the bigger drill I notice it was getting too close to the wall so I stoped and looked at my wrecked one and sure enough its off.

My question is how critical are the pocket walls? The trigger and and hammer will be in the right spot when I finish but one side of the wall with be off. I will post pictures when I get back home I got pissed off and went for burgerking haha.

[savs2k]

nobody?

[krispytapa]

You can probably use anti roll pins and be gtg. They lock from the outside and don't just rely on the tension of the trigger/hammer springs to lock in the pins.

[spdrcr]

Post a picture so we can see what your working with.

I'm sure there is some tolerance for the fire control pocket as well as a minimum recommended thickness for the receiver walls. I don't know what those values are though.

[Swatguy10_15]

Finding a measurement for "wall thickness" might be kinda iffy. It seems most concentrate on the measurement tolerances for the fire control pocket and the minimums thereof.The main pocket is usually .690 wide..Thats the minimum for everything to function as it was designed..
Where the pockets steps down (where youre safety selector is) is usually right around .438..Backing into where the pocket widens back out (where it butts up to the buffer tube threads is .500..
Ill post another reply later on today, I machined my 80%er to the specs and will shoot a measurement fo actual wall thickness..Unless you made it paper thin Im sure it will be fine..

[goober]

Swatguy10_15 is pretty much on it. the exact thickness of the walls is not the crucial dimension; as long as its thick enough to hold the pins in place and stand up to use, it will probably be OK.
pix would help.

[savs2k]

I can fix most of it but what im worried about was the first hole i went to 1.249 depth goes around the hammer pin. What worries me is that the hammer would not be resting correctly on the walls. I am 90% confident If I could get to a mill i'd be able to finish it easily with some blueing. I have pics but my camera is in my car at the moment so i'll have pictures up tonight.

[ar15barrels]

[Seesm]

I can fix most of it but what im worried about was the first hole i went to 1.249 depth goes around the hammer pin. What worries me is that the hammer would not be resting correctly on the walls. I am 90% confident If I could get to a mill i'd be able to finish it easily with some blueing. I have pics but my camera is in my car at the moment so i'll have pictures up tonight.

Where are you located...? I have a mill and may be able to help you.

[Swatguy10_15]

Seesms the man! Has a GREAT setup and makes 80% operations 80% easier!

[Swatguy10_15]

I can fix most of it but what im worried about was the first hole i went to 1.249 depth goes around the hammer pin. What worries me is that the hammer would not be resting correctly on the walls. I am 90% confident If I could get to a mill i'd be able to finish it easily with some blueing. I have pics but my camera is in my car at the moment so i'll have pictures up tonight.

Hammer resting on the walls?

[Seesm]

Seesms the man! Has a GREAT setup and makes 80% operations 80% easier!

Haha thanks for the kind words!! I have made enough mistakes now I am pretty good at it... Since I helped you mess and fix your sup... I messed and fixed mine up as well!!

[savs2k]

Hammer resting on the walls?

not the hammer it's self but the bottom part of the hammer where the pin goes through. Pics will be up in a few mins. Thanks seesm. I'm gonna try to get my buddy's dad to let me use the mill at his shop but if that doesn't work i'll let you know. I'm from san jose but im picky about doing things right so if you're within 2 hours i'm up for a drive

[savs2k]

the pics are kinda crappy but it's the best I could get. the flash blurs out the whole holes so I had to do it this way.


as you guys can see the whole are a bit off from the red outline. The outline isn't perfect either. I just aligned the adapter correctly this time and colored it in to see how far off it is. the hole on the top right is the only one to full 1.249 depth but that is the one I am worried about. All the 37 1/8 holes are now misplaced. The other 2 3/8 holes are only 1/4-1/2 way through. I stopped when it looked funny.

[ke6guj]

that doesn't look too bad. I would suggest using a mill and trying to mill the right side first, smooth out the drill holes and then work your way left until you are to spec If you clean up the left side before you hit the cavity specified width, measure how much more you have to cut, and split the difference to get it back on center. . Dig up the blueprints for the fire control cavity and you still may be able to cut it to spec, centered. And with a mill, make sure you cut the rear takedown lug area so that it is inline with the front lug area. It looks like you may be able to get the FC cavity within 0-.050" of center, and have it be the proper width, which shouldn't be a problem.