WTB: AR15 Receiver Face Lapping Tool

[Bigs28]

I did it by hand vertically just like the video posting. I suppose I could use it again and another upper will fit in that groove but at some point it will be to deep and you will start grinding the sides as well as the surface.

[blackholegun]

What was the grit of your lapping compound

[bj139]

Is this true...Have you seen this? I have never used one but am thinking of using them. I wouldn't have thought there is even wear in dissimilar metals. An aluminium receiver vs. a hardened steel tool...

The grit may be embedding into the aluminum and so scratching more on the steel than the aluminum as hardness differences would suggest.

[blackholegun]

I just received my PTG lapping tool today.
Also some permatex 80037 valve grinding compound.
Had an Anderson upper laying around, first experiment.
So I put a little of the lapping compound on the face of the tool and did everything by hand.
Turning it back and forth for maybe a minute at most and then cleaning everything off and checking my progress.
I did this three times and had a very evenly exposed aluminum surface all around the receiver
The tool itself did have what I would call a "witness ring" from the contact from the receiver.
Not a grove, could not discern the difference from the rest of the face other than a simple color change in the surface.
On to my Aero upper, same procedure, seemed to take a little longer, maybe better anodizing?
Anyway, end results were the same.
Two down in less than 20 minutes start to finish, tool has nothing more than reference marks that I do not think you would even be able to measure.

[Bigs28]

Just got home from work. I used wheeler 320grit lapping compound. I did one receiver by hand vertically. There is a noticing ring and when I run my finger across it I can feel a groove. I have pictures on my phone I can email or text but I don't have my laptop to shrink and post. I feel confident in doing another upper with the tool but like my original post said, I would not want to lend it out because I do believe that the groove will continue to get deeper with each lapping.

[TheDroz66]

I have lapped two uppers - neither seemed to be out by a lot, and my Wheeler lapping tool has worn the black off but no significant groove yet. I used the 220 lapping compound that came with the tool, but I think I will get some 300+. I didn't notice before but the surface was not that smooth to start with - you can see the circular tool marks in the anodized area. I may try to find a local shop that can smooth this out for me. If anything those tool groves have been smoothed out so maybe that is how the groove starts. If they were perfectly smooth to start with maybe they would last longer? Are other tools this way, or are some of yours smooth?

Lapping tool.jpg

[bj139]

I did one receiver with my Wheeler tool and the face of the tool AND the receiver were NOT square and smooth.
I realized this did not matter as long as the tool was a nice fit in the receiver, which it was.
The tool face and receiver face were both nicely square after lapping one.
There is a slight groove in the tool which does no matter either, unless it gets too deep

[sneaky one]

Aside of bg139, you can also Contact 65 Whelon, he has that tool, he squared an upper for me. As an idea- maybe mail it to him, with a $15 inside, he can mail it back then-done deal ?

He does quality work, has a Ton of machinery also- Lathes , presses , etc. A few others here have that lapping tool- they can chime in if they could also.

Awesome ideas to share special tools, or small bits of labor, or money or trades, ?

Grrr Team efforts. I love em".. I've been involved in quite a few here.

[Wheelhorse]

After doing several uppers, I had the face of my Wheeler resurfaced in a lathe. Just didn't like grooves
it was leaving.