Longevity, Accuracy Tips for the AR15

[LRRPF52]

So after you coat it together you let it air dry then disassemble & bake? Im guessing your not baking the scope right? Do you blast your parts or just degrease?

I do the parts individually with the base coat, to include inside the lower receiver in every nook I can find, inside the magwell, and sometimes inside the upper receiver.

I have used blast tanks, sanding, and no roughing of the surface at all on my personal guns to see the difference. I even coated melonited barrels that have a very smooth, hard surface, and couldn't believe that it behaves like a sand-blasted job. My stainless Grendel barrel was the first one I tried without abrasing the surface, and it has not had a single scratch or ding even mark the surface.

I still will abrade/roughen the surface if I am doing it for a friend, since NIC calls for it, and I understand the concept of having a rough surface for better purchase and adhesion of the compound ceramic-epoxy/enamel secret sauce. It's pretty standard surface coating 101 to clean and sand a surface for a uniform and stronger coat.

Yes, you can bake quality scopes at lower temps, and the one in the pics is baked. I contacted Vortex about this when I heard you could do it, and they confirmed it with me, stating the temp limits of 200F. Since I am at higher altitude, I use a bit lower temp than that of 180F, being that lower atmospheric pressure affects gas purged tubes in high heat differently. I even baked my Vortex spotting scope, and my 1-4x GRSC, no issues after several years of pretty hard use.

[Lead Chucker]

Thanks for the info LRRP52! I was wanting to Cerakote but didn't want the hassel of blasting since I dont have a blaster at home, thats why I was going to duracoat. But now I may try the Cerakote. Baking isnt a problem so I will get what I need and give it a shot. What size needle are you using in your airbrush? I know most people are using HVLP guns because the Cerakote is thicker than paint and Duracoat. Thanks for your help and info!

[LRRPF52]

If you aren't going to blast, I find that new anodized and parkerized surfaces already have excellent surface adhesion properties to them, and this is consistent with other Cerakoters' experiences as well.

If you want a part to have a more abraded surface, you can use fine grit sand paper, then clean and acetone bathe. One thing is for sure, you have to clean your airbrush immediately after use, as the Cerakote will clog it badly.

[Lead Chucker]

Cool, thanks for all the info! Im was on their site today. Think I may try their 6 color starter kit with the HVLP gun

[Kikn]

I was doing some extra reading on this and ran across this at midway...

http://www.midwayusa.com/product/810457/ar-stoner-upper-receiver-lapping-tool-ar-15?cm_vc=subv1821295

http://www.midwayusa.com/product/821295/wheeler-engineering-delta-series-upper-receiver-lapping-tool-ar-15?cm_vc=subv1810457

[NugginFutz]

I was doing some extra reading on this and ran across this at midway...

http://www.midwayusa.com/product/810457/ar-stoner-upper-receiver-lapping-tool-ar-15?cm_vc=subv1821295

http://www.midwayusa.com/product/821...vc=subv1810457

Two days ago, both were on back order. The Wheeler version is now available. Get 'em while their hot...

[stanprophet]

After much reading here before a couple of builds I decided to buy the lapping tool. My dad kind of gave me one of those looks, like I was smoking something. And much debate with someone that is as stubborn as I am, I asked him what will it hurt? Well he could not really answer that, so he actually ordered the tool before I could. When we started to put together the 300 blk rifles I was the first one to lap the receiver. You should have seen his face when it started to look like the receiver in LRRP's first picture.

Now I cannot say for sure what it did for the accuracy of this rifle, I can say it shoots much better than I thought it would. With a $135 SS barrel, with nice finish quality, and a nice looking bore. I will get a chance to do some testing but both his rifle, and the rifle I built for the wife is showing MOA accuracy. So my carbine is a 16" Wilson SS NM 1-8 chambered in 223 wylde. This rifle is already MOA or better with my 55gr FMJ loads, and put down some amazing shots at 500yds with 77gr SMK's. I tore this thing down to refinish it, and it will be lapped with the tool. The price of the tool kind of makes it a no brainier when building uppers.

LRRPF52:
Thanks for this post, and the knowledge you share with everyone here!

[BjornF16]

Is the Wheeler version decent?...I refuse to buy PTG...

[Dave Bob]

I have the wheeler version and have not had any problems with it so far. Understand that I've only used it 3 times, so don't know about longevity with the spring thingy.

Dave

[wheelguner]

+1 on the Borka. Here is a link to a test at 6mm BR:

http://www.accurateshooter.com/gear-reviews/borka-compact-torque-setting-driver/

I readily and proudly admit to being a "tool junky" and having had a number of passions/hobbies/addictions over the years. These have changed as have the tools acquired for each one. One thing has never changed.....I NEVER get rid of any tool. So I have the Snap-On inch pound torque wrench from my 2 stroke motorcycle racing days, the aforementioned Borka (which I REALLY like) and the nice T Handle Torque wrench from Brownells (an xmas gift from a customer). bwaites is pretty much on the money about torque wrench accuracy. I am very fortunate in that I have access to torque wrench testing/certification testers that use strain gauge technology. I was very skeptical of the claims made for the Borka and I as well as the techs in the standards dept that I mentioned were amazed at the accuracy and repeat-ability of this thing. It isn't cheap but my father, a master carpenter, taught me that you can buy and replace cheap tools over and ever or buy quality once. I have lost track of the broken off screws I have removed or stripped threads I have repaired for customers and friends over the years. Torque limiting tools are your friend!!!!!

[Buster]

I readily and proudly admit to being a "tool junky" and having had a number of passions/hobbies/addictions over the years. These have changed as have the tools acquired for each one. One thing has never changed.....I NEVER get rid of any tool. So I have the Snap-On inch pound torque wrench from my 2 stroke motorcycle racing days, the aforementioned Borka (which I REALLY like) and the nice T Handle Torque wrench from Brownells (an xmas gift from a customer). bwaites is pretty much on the money about torque wrench accuracy. I am very fortunate in that I have access to torque wrench testing/certification testers that use strain gauge technology. I was very skeptical of the claims made for the Borka and I as well as the techs in the standards dept that I mentioned were amazed at the accuracy and repeat-ability of this thing. It isn't cheap but my father, a master carpenter, taught me that you can buy and replace cheap tools over and ever or buy quality once. I have lost track of the broken off screws I have removed or stripped threads I have repaired for customers and friends over the years. Torque limiting tools are your friend!!!!!

Man you seriously need a job doing TMDE....

[stanprophet]

We have the wheeler version, works as it should.

[dmsims21]

Is the Wheeler version decent?...I refuse to buy PTG...

I just got the wheeler lapping tool in the mail. It is ok. I like the flexible shaft. I think it is a good idea. The surface finish isn't the greatest.
The lapping surface isn't perpendicular to the body. It is slightly not perpendicular. It may not be enough to cause a problem, but I am going to have one of the local machine shops square it up.

[wheelguner]

Buster,
Been there done that so long ago I've worn the T-Shirt out. was a part of the fore runner of this:

http://www.marcorsyscom.usmc.mil/sites/pdmtmde/

And later for the AeroSpace Co EMS Technologies supporting programs like Jstars, Dark Star, Phalanx and Nuller. I have had equipment in my hands (gloved of course) that landed on Mars.

I am Former Marine with a wide Geek Streak. So many toys and so little time!!!!

[dmsims21]

Some on this forum and elsewhere on the interwebs have questioned the ability of the lapping tool to square the receiver face to the bore.
It has been noted that the lapping tools are cut to 0.997" and that the receiver bore can be as large as 1.002". That leaves 0.005" of clearance that the tool can be off axis.
The 0.997" portion of my wheeler lapping tool is 5.5" long. Imagine the tool sitting in the receiver in the worst off axis position. The tool would contact the receiver bore in two places. Connecting the contact points would create a right triangle with a 5.5" leg and a 0.005" leg.

atan(0.005/5.5) = 0.052deg or 3.13MOA.

3 MOA isn't that bad. Who has taken a brand new upper and mounted a new scope to it with the windage in the center of its adjustment range? I have and I was off by more the 3 MOA.
I know there are other tolerances in play, but the worst case clearance won't add a whole lot of error.

Some important things to note.
1. That angle only puts the bolt lugs off by 0.00067". There should be enough wiggle in the bolt and carrier to overcome that gap and get even lug contact. (Just and educated assumption on my part.)
2. Even though the receiver face is non-perpendicular by 3MOA, the receiver face is very flat. The flat face will keep the barrel from rocking back and forth on two high spots.
3. It is possible that the tool will self-center a little bit with a heavy oil film.

If I made a mistake, don't beat me up. It is late and I graduated college a long time ago.

I will post a sketch soon.