"Precision" Build---A Couple of Questions (re-post)

[tophernj]

(re-posting as I had this in the "wrong" forum, apparently.)

Howdy all.

I've been collecting parts for a "precision" AR build and am, as always, seeking advice from those that are more knowledgeable than myself. Most of my questions are centered around the upper. The lower is built and done. I have a forged Aero, Timney Targa 2-Stage trigger, and a Magpul 404 MOE stock as the basics.

Rifle's use will be prone and bench shooting to 300 for the majority of its life with some shooting to 700 if/when I get the chance. I plan to glass it with a 1-6 or 8 or a 2.5-10, so basically a lower mag scope for fun shooting. Barrel will be an 18-20". Caliber is up in the air but it's between a 6.5G or .223. FWIW I'm not at all worried about the caliber at this time. I'm still puzzling out the pros and cons for each.

The upper is where my questions come from.

First up: How much of a difference would a billet upper make over a forged? I understand that the billet is stiffer but does that make so much of a difference? Additionally, is it worth it to "face" the upper and should I look to "bed" the barrel into the receiver and how much of a difference would that make?

Thanks in advance.

[GH41]

(re-posting as I had this in the "wrong" forum, apparently.)

Howdy all.

I've been collecting parts for a "precision" AR build and am, as always, seeking advice from those that are more knowledgeable than myself. Most of my questions are centered around the upper. The lower is built and done. I have a forged Aero, Timney Targa 2-Stage trigger, and a Magpul 404 MOE stock as the basics.

Rifle's use will be prone and bench shooting to 300 for the majority of its life with some shooting to 700 if/when I get the chance. I plan to glass it with a 1-6 or 8 or a 2.5-10, so basically a lower mag scope for fun shooting. Barrel will be an 18-20". Caliber is up in the air but it's between a 6.5G or .223. FWIW I'm not at all worried about the caliber at this time. I'm still puzzling out the pros and cons for each.

The upper is where my questions come from.

First up: How much of a difference would a billet upper make over a forged? I understand that the billet is stiffer but does that make so much of a difference? Additionally, is it worth it to "face" the upper and should I look to "bed" the barrel into the receiver and how much of a difference would that make?

Thanks in advance.

A heavy billet upper may have a slight edge over a mil spec forged but it will be overkill on your lower (And look like crap). Facing a quality upper is a waste of time. Buy a BCM forged receiver and don't worry about barrel to upper fit.

[Rogue556]

Buy a BCM forged receiver and don't worry about barrel to upper fit.

This^

I had the same dilemma building my 18" rifle and ended up going with a stripped BCM upper. I did a decent amount of research on upper recievers and never could find any hard evidence that the beefier upper recievers actually improved accuracy. There are guys shooting (at various distances with specific loads, in near perfect conditions) sub MOA with standard milspec uppers, and others with VLTOR MUR and similarly built uppers that struggle to shoot MOA under those same conditions, and vise versa. Now, I'm not saying they don't make a difference, but I think (if they do) it's so miniscule that you'd be better off worrying about other areas first. (There has been some talk about beefier upper recievers, like the VLTOR MUR, helping keep wear down on internal parts over time, helping with POI shift with a suppressor attached, and keeping the upper from blowing apart in the case of a catastrophic failure.. but as far as accuracy goes I don't think you'd ever notice).

[556BlackRifle]

With Aero lower I agree with GH41, go mil-spec. If you go with a matched upper / lower billet set from a good manufacturer, you may have a slight edge but the question is, would it be enough to make a noticeable difference? Possibly. I've used billet uppers from a number of manufacturers and found that there is some variability between them and also some don't play well with certain other brands - so mix and match may or may not work depending on luck of the draw.

Regarding facing, do a forum search. It's been discussed here a number of times. I can't comment on bedding the receiver extension into the upper. Never done it and don't know anyone who has.

[Kansaswoodguy]

I personally use heavy walled uppers for my precision builds. I have a slick side DPMS upper and a couple of the Mega SBU uppers. If the billet upper your looking at is heavier built than a mil spec than you may see a difference. A more rigid upper will promote accuracy imo. I do think a tight barrel to upper receiver fit is important if the dry fitting of the two parts is tight i.e. it takes a rubber mallet to seat the barrel or you have to cool the barrel in the freezer and warm the upper with a hair drier to fit together. I figure it's plenty tight. If the dry fit is loose I loctite them together. I've never bothered to lap the front of the receiver but at what point do you quit if the argument that the upper needs lapped then the rear face of the barrel extension should also need lapped, where does one stop once down this road. If your planning a heavy bull barrel build I would recommend a heavy walled upper if your going with a mid or light weight barrel it may not matter.

[tophernj]

So I wound up grabbing a BCM blem upper. It showed up last night and looks good to me, honestly. I have a MI SS G2 on it and am now on the hunt for the right barrel.

Little by slowly we're getting there.

[Tael762]

I'm building a bench shooter too. Locktite on the barrel extension seems to permanent. the concept does have merit though. I just know I will be reconfiguring the rifle later down the road.

[RobertTheTexan]

So I wound up grabbing a BCM blem upper. It showed up last night and looks good to me, honestly. I have a MI SS G2 on it and am now on the hunt for the right barrel.

Little by slowly we're getting there.

I picked up a BCM blem for one of the builds I did, can't remember now. I think my 14.5. I had to pore over it find the fault. Their standards are pretty high to call what I had a blem. Since you got it, no sense mentioning my recommendation, but I will anyway. I think BCM is a great option. I will also say that I am a stone cold believer in the Vltor MUR1A. It is as good if not better than any upper I own. (Yes that's a rather nebulous effort to quantify that, but I'm still sticking to my statement.) I do have that BCM Blem, a BCM regular upper, a Colt upper, an Anderson upper (my first build guys...what did I know?)) and about 4-5 Aero Precision uppers. Still in all of that, the best shooting AR I own has the Vltor on it. Concinkydink? who knows, but it is what it is.

What barrel are you thinking on? There are some really good SPR choices out there. You may consider these:

http://ballisticadvantage.com/18-inc...rel-ops12.html

http://ballisticadvantage.com/18-inc...um-barrel.html

BA makes some really good barrels, I have an 18" Performance rifle length on my SPR. It's a good barrel.

[tophernj]

Thanks much for the advice and recommendations.

The BA barrels are apparently very nice and for sure under consideration. I'm also lookin at the Odin Works barrels. Not sure where I'm at with everything at this time. Hell, I'm still not 100% on .223. A 6.5G is an option as well. I'm hoping for a touch of "kismet" to help me figure it all out.