My upper now lapped

[NoFail]

I came across a guy who does gun smithing and he hooked me up big time. He builds AR15 uppers and laps all of his upper receivers. When I told him I wanted to lap my .308 upper he said he didn't have a tool for it. I knew there wasn't a tool so I said we can make one, so he did  <munch> He had it made with some super hard chromoly. He used a caliper to measure my uppers bore and then just went and had the tool made just like that. He was very excited to do this on his first .308 AR. So

now he has a lapping tool for our .308's  ;D  Also he pointed a slight mark occurring on one of the bolt lugs from engaging it's barrel extension counterpart lug. He

polished an area on the barrel extension lug that was causing the mark and now the bolt even seems to engage smoother after he went ahead and torqued the barrel, but then again it could be that it's that much better because of the lapping. He took good care of me and my rifle.

If anyone is interested in having this lapping service, or whatever, done for your .308 you can find him at www.civtactical.com

[NoFail]

You can tell how flat the end is becoming

[NoFail]

;)

[unforgiven]

8)

[outkastsl]

Very nice!  Will the gunsmith produce these for sale? 

[NoFail]

Very nice!  Will the gunsmith produce these for sale?

The tool, no. He will use tool to lap all AR-10/LR-.308 uppers he builds or anyone can send him his/her upper for this service. And if any y'all's uppers were anything like mine you would want it done if you knew. I couln't tell if it was flat or not until he got stared with the procedure

[Tripledeuce]

    Does it lap anything other than the flat?  Sorry if this is a stupid question.

    Terry

[NoFail]

    Does it lap anything other than the flat?  Sorry if this is a stupid question.

    Terry

No that is all it does.

[Jgun]

I have never lapped any of the AR's that I've built, but have been recently told that it's very common for the face to be out of square, which would (I think) be likely to cause uneven bolt lug engagement. I wonder why the receiver manufacturers don't pay close attention to this? I'm not planning to start taking my assembled, functioning AR's apart to check them on this, but I may consider making one of these for my next AR build. Since I've never used one before, maybe those that have used the AR 15 ones could answer a question for me? The tool itself looks to be fairly simple, with a close fit in the bolt carrier bore and barrel extension bore, being, I would think, important. What I'm wondering about is if the part of the tool that actually rotates and does the lapping would need to be hardened so that it doesn't wear at the same time that it's lapping the hardcoat off the front of the receiver? Anyone care to comment?

[Tripledeuce]

  As a gunsmith, the steel tool aginst the aluminum reciever is plenty hard enough, but you will need to re-square the tool.  The frequency of which would change with the hardness of the recievers, and the hardness of the finish.

    Those hard anodised recievers are TOUGH!!!

  Respectfully

  Terry

[NoFail]

What I'm wondering about is if the part of the tool that actually rotates and does the lapping would need to be hardened so that it doesn't wear at the same time that it's lapping the hardcoat off the front of the receiver? Anyone care to comment?

The one we made is from the hardest chromoly there is.

[survivalshop]

Not sure if you would really want to take the finish off that area (steel against aluminum )

I use a different method of checking to make sure the face is square  , ya just want to make sure it has no imperfections in the finish.

This method has been around a while & I have not seen any scientific data of it to say it does any thing to the accuracy of the rifle .

The only thing I have seen is some one saying how much better the rifle shoots after pulling the bbl. off & doing it , hardly scientific.

If you think the rifle will shoot better doing it , go for it .

Kinda makes ya wonder what effects this procedure has on Head spacing . Not to mention getting lapping compound in the upper receiver's barrel extension area. I liked the one person here that used a sanding disk , cut to the face dia. of the tool . No way you can get the wrong area lapped , that way.

[NoFail]

Not sure if you would really want to take the finish off that area (steel against aluminum )

I use a different method of checking to make sure the face is square  , ya just want to make sure it has no imperfections in the finish.

This method has been around a while & I have not seen any scientific data of it to say it does any thing to the accuracy of the rifle .

The only thing I have seen is some one saying how much better the rifle shoots after pulling the bbl. off & doing it , hardly scientific.

If you think the rifle will shoot better doing it , go for it .

Kinda makes ya wonder what effects this procedure has on Head spacing [glow=red,2,300](you just have to know when to stop, which is soon)[/glow] . Not to mention getting lapping compound in the upper receiver's barrel extension area [glow=red,2,300](it's not like you slop the stuff on there, use just a little, there was no problem)[/glow]. I liked the one person here that used a sanding disk , cut to the face dia. of the tool . No way you can get the wrong area lapped , that way.