How To Lap & True An AR-15 Upper Receiver For Optimum Accuracy

Understand the philosophy behind the lapping but when using a handheld drill like that…what ensures that you're not applying some catywompas pressure and not actually making it true?

I don't buy Minimum Spec gear (a.k.a. Mil-Spec). Aero Precision with their enhanced uppers resolves this issue for me.

Hello Mr. Gunsngear,
I know this might be a little off topic of this video but I don't have Facebook to send you a message there. I am wanting to get a new build going with the Geissele URGI upper receiver and I want to make an exact or close to exact clone or replica of the actual rifle that the military will be using. Can you please give me some pointers on what basics of the rest of the parts of the build I need to get exact as possible like what lower receiver brand and the other main basic components that go into the building minus the optics and other ancillary accessories. Your help or anyone in the comments section would be a great help. I have an idea of what and how I want to set it up but I'd like to hear other input on the future build.
Thanks.

For you lazy folk, blackstone arms sells aero uppers that they square the face of

Practical, valuable, not often talked about info. Great content as always. Buuuut, I feel like we need to raise a fund to buy you a tool box, bruh. 😀

I'd much rather see the back side of your head than your backside! :)))

Thanks for taking the time.

BIG DADDY UNLIMITED is a company that is run by Patrick, a discrminating racist.

They don't even sell their own product. they sell stuff for other distributors.

Nice but I think if you're going for a true accurate rotation/hole, a drill press would deliver optimum results.

Bruh, don't put the lapping compound on the receiver until you have the tool inserted. You just pushed your grinding sauce inside the receiver. Big no no.

And you probably want to remove all the anodizing until the face is raw aluminum.

Great vid, but also Do a vid on unlocking adjustable gas block screws that are carbon locked.

Brownells SCREWED me once. And you know the old saying that George Bush Jr couldn’t get right. Screw me once shame on you. Screw me twice shame on me. See George it isn’t that hard…

Completely unnecessary unless you are buying off brand uppers, but hey, why not.

You have to lap the barrel extension also .

I prefer to do this with the work in the vertical so the weight of the drill isn't biased to gravity and lapping the down side.

Another major benefit to a square face is uniform bolt lug engagement with the extension.

I also apply light oil to the shaft of the tool so it doesn't deface the raceway inside the upper, then clean everything out afterwards.

The back of your head looks cool. I wish I had one of those!

Sounds like a solution for a non-existent issue

Will be hat affect head spacing?

Jesus, did it too fast. Take your time

Lap every single one I put together

I hope your barrel extension is square…. lol

Instructions unclear, but at least now my buffer tube will be nice and true.

I just bought a lapping tool this week from G&G. Good timing

Good video! You to secure that vise a little better. 😉

I was under the impression this is most important in delivering proper barrel nut torque when clocking the gas tube. I dont see how this would improve accuracy. The chamber and bore is an assembly "separate" of the receiver. Unless your optic is way out of concentricity of the bore or has crazy parallax or something i am not seeing being the issue…I guess if you could make sure the barrel extension mating surface is true too, this could impact repeatability, but probably not noticeable shooting within 500m, especially with xm193 or 855, like most AR owners

Took my target build apart last year and done this, found no difference in accuracy, still 1/4 at 100 yards. And it's a $40 Anderson.

didn’t even know this was a thing. learn something new every day!

The cleaning lady was off this week it seems…and about that rock and roll vise……

I have been doing this for a while, I set the upper vertical so you get even lapping on the upper. What happens when you do it horizontal is gravity pulls the tool down and its never 100% true. By doing it verical gravity works with you and you get even lapping. Also I dont use a drill, I do it all by hand that way I have more control over how much is done, with a drill ots easy to overdue. I only go till there is an even silver ring showing. I have always put the compound on the tool not the upper, I am not sure there is a difference, just the way I have always done it

Higher IQ people have junkier work benches and dressers, it's because they know where everything is

"sometimes it's harder than that." we not doing phrasing any more?

This seems dumb, like lapping scope rings by hand

I start out like you, with a work bench that looks "fully employed". On receivers, I usually use an 80 grit lapping compound and take it pretty slow. Even with technology being as good as it is, lapping will accurize your build. I'm no expert, by any means, but lapping an upper and lapping scope mounts are standard operating procedures on my bench. Also, I generally put a little oil/lube on the shaft of my lapping tool. It glides better at the opening, making insertion in the receiver a breeze. Feel free to use that advice in any of life's applications.

You just need wall mounted areas to hang your crap.

Yes sir, if it’s an Anderson upper I guess you have to that!

is this something you think is usefull on a BCM upper or is the quality there in the first place?

Great video! Have you ever done a before and after comparison to see how much the accuracy improves?

I always do it with the receiver vertical so gravity is working for me instead of possibly putting more force on the lower edge.

Hard pass

Haha and tighten that vice up! Just buggin ya man, appreciate the videos.