For the 2nd time in two weeks I did an enormously irresponsible thing.

An impulse buy at the local shop for a decent price for something I didn't really need. I think it had been sitting in there a while.

I'm going to put it in my Aero M4E1 build. I'll keep the Hanson barrel as a spare.

This one appears to have rifle length gas, but they give you a high quality tube with the barrel.  















BTW, what does that little "S" mean on the extension? Does that indicate the blank it came from maybe?

Thank you for the reply.
I thought about this after I posted the question. The extension is separate from the barrel so the marking probably wouldn't be for the blank. I have a couple of Schmid enhanced GI triggers which have been good.

489 out the door.

Thanks. I will look this over for sure.

I will do that. Should be able to get it installed today and out to the range on Friday or Saturday.
Thanks again.

This is not exactly the right rifle for this barrel and I'll rarely be able to feed her match ammo, but here she is:

Aero M4E1 receivers

The PROOF 16 in. 223 Wylde barrel, 1-8, intermediate gas, which I only recently learned about and the matching included tube

Aero .750 click adjustable gas block

MFT Evolve 3 prong fh/brake

UTG Pro Handguard (USA Made)

Magpul ambi sling loop end plate.

Magpul bipod

Magpul Pro iron sights

Strike Link mini hand stop

CMC 3.5 pound flat bow single stage trigger

Aero logoed nitride BCG

B.A.D. Enhanced bolt catch/release

CMMG enlarged mag release

Radian Talon single side safety (set to 45)

Raptor LT CH.

Aero enhanced buffer tube

Bexar Arms flat wire spring

Strike modular buffer, setup to 3.9 oz. (this may have to change)

Magpul MOE+ grip.

Magpul DT buttstock

The controversial Aero lightweight mount and equally controversial Swampfox Arrowhead 1-8

Assorted KNS, Bexar, CMC etc. springs, pins, detents, castle nut etc.

Thanks. I love that rifle.

Quick question. I'm going to shoot it as is and see how it does, but suppose I wanted to shim it eventually. What shim material would you suggest? I'm a huge JB Weld fan and can get that locally if need be obviously. I've used JB Weld to fix all kinda stuff. You'd have to leave a film of oil in there for any hope of getting it back out in the future though.

The extension was snug in the receiver, but went in pretty easy.

Loctite 620 sleeve retainer

.001 or .0005 SS shim stock on the bbl extension if needed.

Lathe square the thread face on the receiver where the extension seats since you have it apart.


Edit: 620…..

Looks like THIS might be a good idea?

These lapping tools have always made me nervous. I can't get it outta my head that I'm also enlarging the bore of the receiver too.

No,  if you use a lapping tool vs having it lathe turned,  lubricate the circumference of the mandrel as to NOT induce any wear in receivers bore.  You are lapping the receiver thread face in an effort to square it with the barrel extension bore.

If you were to stand your stripped receiver on the bench,  threads down,  the area touching the bench is what your lapping.

This is a lathe turned receiver face,  same effect as lapping but more precise.

Right. I understand that. The thing is, you are still running the mandrel inside the bore where the barrel extension mates to the receiver. And pretty tightly too, or it wouldn't square the nose right. Some lube would go without saying.

Of course, then shimming/gluing would probably take of that and I see enough credible people reporting success with these tools to convince me that they work. It's just my stubborn mind making things rough on me.

The lathe method would be optimal, but I'm not going to be able to get that done. A lapping tool I could eventually do.

Step one is to get it out and see how it shoots as is and I don't even have any ammunition at the moment that will really tell me that lol. I have quite a bit of 556 range ammo, but no match grade stuff. Will probably grab a few boxes of AAC.

Somebody should invent a lapping tool with replaceable hard Teflon sleeves maybe a couple mils thick. The sleeve would sit stationary inside of the receiver and the slightly reduced diameter mandrel would run snug inside of that. Use the sleeve a few times or until it starts to wear and then replace it with a new one.

You spent almost $500 on a barrel but can’t spend $40 (including shipping both ways) to have Paladin (tp555(at)vfemail.net) lathe turn the front of your receiver?  Uh, ok.

Touche and I was waiting for somebody to bring this up. Truth be told, I shouldn't have bought this barrel. I don't even have the money to run it consistently like it should be.

Truth also be told, my Hanson barrel was giving me right at MOA and maybe a hair's worth of change with factory X-Tac ammo.

This was an impulse buy with a story behind it that I won't get into.

I will make some effort to maximize it's potential as best I can.

Like I say though, step one is seeing how it shoots like it is.

Very good sir! Thank you again for the good info

Maybe I'm especially dense today, but which one is this.

$39 for the lapping mandrel plus lapping compound for a mehh job?

$40-$50 to have it lathe turned and be gnats ass square…….

I know where I’d put my money

I'm just exploring possibilities at the moment. I like the idea of having the tool too. If it works like I want.

How does THIS look for accuracy? I've never bought anything except range ammo, though I have seen that 77 grain Sierra Match King projectiles are often associated with top notch ammo for accuracy. How does it compare to THIS ?

Does anybody know?

Thanks again.

I bought three boxes of the 77gr. SMK before I saw this. I should have gotten two of each, but didn't think of it at the time.

Have done a half dozen Aero uppers with mine (Wheeler) so far and about that many Colt uppers and never noticed anything fitting in a 'sloppy' way like you describe.

Can compare measurements if you wish (willing to bet you have very good measuring tools as do I) but fairly sure you just got a bad one and that they are not 'all' machined like that. Would have definitely sent mine back if was as you describe yours was...

Will also add that because of 'tolerances' if you sit down to do several new / unfired uppers at the same time (and from the same exact brand) it is not going to be unusual to find one or more where the 'fit' of the lapping tool is a little looser or tighter as compared to the others.

Obviously if the dia of the tool is not changing but the 'fit' feels different between different uppers than the difference is in / with the uppers...  

No way in hell you would be able to ever tell a difference between either on paper.


The money saved by owning the tool and being able to do several vs the cost of having the same number done on a lathe would add up to a LOT of coin quickly. Money saved that could then be spent on lots of good quality ammo...

I appreciate all the input guys.

BTW. It did finally sink in that the lapping tools are reduced at the length that would make contact with the mating bore of the receiver, thus avoiding the enlargement of that area that I was concerned with

I forgot to tell you the part about my being a moron lol.

This is why lapping is not as precise as a lathe.  Everything is dependent on the fit of the mandrel to the receiver.  Also,  consider the mandrel face wears some with each use.

Can you tell the difference on paper…..?  Not sure,  but it’s a few more variables eliminated.

I have dozens of uppers that I have lapped myself with a mandrel and dozens of others that were lathe turned.  Accuracy wise, I see no difference.  I personally have no doubt that lathe turning is a more accurate way to square the front of the receiver but I am also just as certain it doesn’t matter a lick when it comes to “on paper” accuracy.  The only thing I am dead nuts certain about is that turning, lathe or mandrel, makes sure your sights are centered.  Anything other that that…hypothesizing and conjecture.  JMO.

Yes sir…..In my experience, irons and optics are on out of the gate.

How fast did you run the drill may I ask? Seems to me that some of these guys I'm seeing are running the mandrel way too fast. I'm thinking slower, patient and deliberate is better.

You can just do it by hand

I chuck it in my drill press and run it on its slowest speed.  IIRC it is something like 650 rpm??? but I will not swear to that. Just make sure to keep the mandrel coated in oil and fresh lapping compound on the cutting face.  I use moderate pressure and hold the upper by hand, pressing up on the mandrel.  I lap for about 20 seconds then check progress.  It usually takes less than a minute or two of actual lapping it out to 100% but I stop and check several times, so total time is usually about 5 minutes.  When you stop to check, stop the motor, and just back off the upper from the mandrel's cutting face 1/4 to 3/8 inch or so, use a cloth or Q-Tips to wipe the face of the upper free of lapping compound, look at the progress with a good light, and if needed, apply more lap to the cutting face of the mandrel and lap for another 15-20 seconds.  Repeat until you have 98-100% coverage, but don't over do it.  That is where some people get into trouble.  They go ape-crap crazy and lap way too much off the front but I mean, you really have to go nuts and be half drunk to do that.

 If I have one upper to do, I do it myself, if more than one, I send them to Paladin.  He does such a good job, does it quickly and doesn't charge much at all (shipping both ways is more than the actual jobs) so that it's not worth my time and effort to do them myself unless, as I said, it's a one off.

You can do it by hand if you have nothing better to do with your time.  Personally, if the choices were doing it by hand and sending it to Paladin, I'd send them to Paladin every time.  I tried one by hand it it took forever, so no thank you.  The drill press is the way to go if doing it yourself.  You can also use a hand drill but clamp your hand drill to a bench or in a vise and manipulate the upper on the mandrel.  Doing the lapping while holding the hand drill was not near as easy for me, and clamping the upper in a vise meant using padded jaws to prevent scratches.  Clamping the drill in the vise worked a lot better with no danger of scratching the upper, but the drill press was much better. Do wear heavy leather gloves though in case the upper were to seize up on the mandrel.  You don't want any broken or twisted off fingers.  Only thing easier than doing it in a drill press is to send them to Paladin.

I do very much appreciate this detailed information. Doing it by hand crossed my mind too.

What didn't cross my mind was wailing away on it like a couple of these guys were. Made me wince.

I've only hand lapped and always gotten good results. Made that decision based on seeing people screw up receivers and what they all had in common were that they were using drills. I'm not saying you can't use a drill, only that I know I'm not going to put any odd sideways pressure, over lap, or otherwise screw it up if I do it by hand. Takes longer but, if I were in a hurry I wouldn't be bothering at all.

I'll probably try that first and see how it goes.
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I do have bags. I just turned 60 and my eyesight and structural stability, shall we say, isn't what it once was. I bought a Precision Underground rear bag a while back on somebody's recommendation. I have some other stuff for the front as well as the bipod. Man it's tough to hold perfectly still these days. Even from a good rest.

I was getting decent groups with my BA Hansen barrel though :)
Here is 5 rounds at 100 yards.

Receiver facing really does not have anything to do with accuracy. It does have a lot to do with where your barrel is pointing in relation to your sights.

If you have your iron sights at mechanical zero and the receiver face is not true, you might need a lot of windage or elevation just to get zeroed. Precision is most likely effected by the quality of fit of the barrel extension into the upper receiver. Tight = good, loose = not as good.

Appreciate the encouragement. I got my first AR a few years ago, but my first firearm in 1989. Was never a precision shooter, but would like to think that there's at least some transferable experience in there somewhere.

The above group was with X-Tac 55gr FMJ-BT I got from Palmetto for 8 bucks a box a while back on some sale they were having. For whatever reason, that Hanson Barrel loves that ammunition. It doesn't shoot any other I've tried that good. I never tried any of the high end stuff in it though.

I don't smoke or drink coffee, but I do drink a fair amount of green tea haha.

I was musing over this exact hypothesis a couple days ago.

I'm back to the realization that a barrel like this is probably wasted on somebody like me. I don't think I can shoot it any better, even with good ammo, than I could shoot the Hanson barrel with crap ammo

EDIT: Well, I don't know that for sure and that's the point. I probably never will. I should have just been happy with the BA Hanson barrel and spent the almost 500 bucks on something that would have been more useful to me.

I did have a bit of an adventure for a minute there before I realized that I had the AGB all the way closed. I had rebuilt it to put some fresh Lucas Red n Tacky on the threads of the needle adjuster thing and left it shut from working it back and forth.

I had a single shot rifle for the first couple rounds. Didn't even eject the empty casing obviously.

The trouble is, I don't have money for any of that lol. I didn't have the money for this barrel.

I'm not a whiny poor guy.  I love my life and I'm not complaining about anything except my own lapse in sound judgement. I had a more than perfectly good rifle that I've spent the last few years slowly upgrading into a dern nice one.

Buying this barrel was like buying a Bugatti and not being able to afford the premium gas, tires and tuneups. (a flawed analogy I know, but you get the point)

I do very much appreciate your encouragement once again. Your positive contribution is truly welcomed.

A piece of equipment like this is for somebody who has the time and resources to take it where it was designed to go. I just am not that person. I recognize that. I just wish I would have recognized it before I spent this pile of money on it :)

I'll shoot it as best I can and it will be wasted on me.

Not even to mention that the 1-8 LPVO, which I just bought over the last holiday sales, is quite unsuited to the design of this barrel too.

I have done so sir