Upper lapping

[Megawolf]

I want to build my 1st upper and not just assemble it.

I believe i want to lap my upper. Of course without sophisticated tools to check how square and flat it is in relation to the barrel & nut i performed some professional redneck engineering. I painted a piece of glass black on one side, put my upper flat on the other side of it and shined a light down the inside. I was looking for uniformity but didn't see it....so I'm thinking lapping is a good idea. I already own one baby whose windage adjustments are too far to the side so I'm thinking ill use it at least twice.

Do i put compound on the glass and hope to keep it square or get a lapping tool? If i go the lapping tool I hope the Brownell version is a good one because I'm too impatient to wait 6 weeks for a run of the Pacific Tool & Gauge. What do y'all think? Brownells or go PTG?

https://www.brownells.com/gunsmith-...15-lapping-tool-sku080000182-20220-44377.aspx

 

[N.Ga.Trader]

The lapping tool from wheeler engineering works great, I use it on all of my builds. Its affordable and you can pick one up at cabelas if your in the area. Save time and a little money on shipping.

Sent from my LGL84VL using Tapatalk

 

[MuleShoe]

I’ve used Brownells lapping tool and compound for several years and does a great job! Also they include great instructions with it !

 

[Plinker66]

Git shims too

 

[N.Ga.Trader]

The lapping tool from wheeler engineering works great, I use it on all of my builds. Its affordable and you can pick one up at cabelas if your in the area. Save time and a little money on shipping.

Sent from my LGL84VL using Tapatalk

Its pretty much the same thing brownells is offering, comes with instructions and lapping compound too.

Sent from my LGL84VL using Tapatalk

 

[BLIP]

I thought this thread was about the
Cheetah III

 

[mcdougmd]

Yeah, I was expecting something different too!

 

[Megawolf]

I thought this thread was about the
Cheetah III

That would've been bottom lapping...or is that the other one?

 

[fattboyzz]

I want to build my 1st upper and not just assemble it.

I believe i want to lap my upper. Of course without sophisticated tools to check how square and flat it is in relation to the barrel & nut i performed some professional redneck engineering. I painted a piece of glass black on one side, put my upper flat on the other side of it and shined a light down the inside. I was looking for uniformity but didn't see it....so I'm thinking lapping is a good idea. I already own one baby whose windage adjustments are too far to the side so I'm thinking ill use it at least twice.

Do i put compound on the glass and hope to keep it square or get a lapping tool? If i go the lapping tool I hope the Brownell version is a good one because I'm too impatient to wait 6 weeks for a run of the Pacific Tool & Gauge. What do y'all think? Brownells or go PTG?

https://www.brownells.com/gunsmith-...15-lapping-tool-sku080000182-20220-44377.aspx

View attachment 2027703

cmshoot

 

[cmshoot]

cmshoot

I’ve never lapped an upper. Every AR I’ve built has exceeded my expectations when it comes to accuracy, so I haven’t bothered. It’s always possible that the accuracy would be even better if lapped, I guess.