Upper Receiver Lapping Tool

[shadow65]

I tried the search and couldn't find it.
Does anyone use these? Do they make much difference?
http://www.brownells.com/.aspx/pid=20220/Product/AR_15_M16_UPPER_RECEIVER_LAPPING_TOOL

[ucrt]

I tried the search and couldn't find it.
Does anyone use these? Do they make much difference?
http://www.brownells.com/.aspx/pid=20220/Product/AR_15_M16_UPPER_RECEIVER_LAPPING_TOOL

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I don't see how anything that "chucks into a 3/8" hand drill to easily “square” the upper receiver face on your AR-15" could do the job better than the upper's machinist while it was being machined in a milling machine.

I wonder if upper "un-squareness" is an AR problem???

But maybe it's just me...

.

[bkb0000]

lapping is for spacegun shooters, nowdays. once upon a time, hand-fitting and lapping were part of "building" ars- but these days parts are truly drop in, so long as you go with any known manufacturer.

[shadow65]

Thanks. That's what I wanted to know.:D

[Der Waffenkollektor]

I check uppers for trueness before assembling and all have seemed alright.

The other use I can think of is if you have a barrel bolt that needs too much torque to line it up with the gas tube hole, you could use one of these to remove a small amount of material and fix the problem.

I found one on sale and ordered it so I can work with it and see what I think.

I may find it useful or I may use it as a paper weight. Only time will tell.

[Robb Jensen]

Every once in a great while I use one to allow a stubborn barrel nut to be torqued for alignment. Or to squeeze a small amount of better accuracy but it doesn't do much, just a handy tool too keep in the tool box.

[kartoffel]

That would be a perfectly fine tool to use in a lathe or end mill, but a 3/8 handheld drill? No thanks!

[MarkG]

I can't think of a more worthless tool. Pure snake oil...

[Magic_Salad0892]

I could see a use for it.

https://www.m4carbine.net/showthread.php?t=52405

This guy had a pretty good theory about bolt pressure.

Overall I just liked his results.

If I had one, I'd use it. Just to try and squeeze a little more accuracy.

Bolt gunners use this kind of thing too, IIRC.

[az doug]

The summer of 2009 I attended a precision rifle blueprinting course at Trinidad Community College. It was a very good course and I blueprinted a Remington 700. It took me approximately 28 hours of machining.

The problem I see with the lapping tool is it, even if it is accurate, is only performing half, or less, of the task at hand. You would also need to true the barrel extension surfaces where it contacts the receiver and the barrel nut. You would also have to true the barrel nut.

I do believe in the point of diminished return. For 99% of the people on this forum the added work would not show improved results downrange.

I do believe the tool has a limited use, as others have mentioned, torquing/aligning the barrel nut.

[scottryan]

Waste of money.

[hellbound]

to add, removing the anodizing and exposing the soft aluminum seems like more of a problem than any supposed accuracy gains

[bkb0000]

I can't think of a more worthless tool. Pure snake oil...


Waste of money.

man.. you guys go together like blue skies and sunshine.

[5pins]

man.. you guys go together like blue skies and sunshine.
:lol:

[MarkG]

man.. you guys go together like blue skies and sunshine.

The truth hurts!