Back in 2007 my first AR was an A2 Bushmaster with a 16" M4 profile barrel. After finding ARFCOM and learning more it went through many configurations until it ended up with a 20" Colt HBAR barrel. It was one of the smoothest and most accurate rifles I owned at the time. However, I eventually sold it to finance a suppressor. For the past year or so I have been longing for another A2 as I have several tacticool AR builds now. This past winter I acquired a very nice FN A2 upper and a NIW 20" USGI FN barrel assembly. I've got it mostly assembled but still lacks a few minor parts. I spend most of the year away from home, so it will not be completed until this winter.

That brings us to the following parts. I acquired the pictured Colt A2 upper in the EE about a month ago. It looks pretty dinged up but is 100% serviceable. It as dingy when I got it, but I just scrubbed it with hot soapy water, and a sponge then hosed it down in WD-40. Now it is the perfect candidate for a battle field pick up style build. After seeing many of your awesome builds in this forum I decided I wanted this to be a carbine. Back to the EE, and I found the Colt N1 stock and Colt 4 position buffer tube. The stock was used in service and has rack numbers and tape on it. The buffer tube was new and kryloned by the previous owner. I think I'll keep it as-is.

The only major component left to acquire is a barrel. I'm thinking of picking up an EE special 6920 barrel. I'd much prefer to keep it mostly Colt. I believe I have a set of skinny CAR handguards in the parts bin. I will most likely throw in a bcg I already own unless I stumble upon a Colt for a steal. This will not be an accurate clone by any means and will have a few modern accoutrements. All of my ARs get BCM charging handles and 51t mounts. This one will probably get a 51t 3 prong flash hider. Additionally, I have a lower for it that will have a MOE+ grip installed. The plan is for this to be a "BFPU tribute" carbine, resembling a 727/BHD era gun. I'm considering adding a proper Aimpoint 5000 down the road. I'll still be gathering odds and ends the rest of the year and screw this one together in November/December.

Sounds like a good plan. The BFPU build I did with one of those receivers is actually one of my favorite builds ever. Good luck and in for pics!

Sounds wonderful!

I love BFPU builds. Currently working on one myself. It's tons-o-fun getting new parts of a build to match the "I seen some shit" parts.

ME TOO!
Those look like a great start OP.

Man I love "well seasoned" parts  I started my BFPU 727 build and found an M4 barrel, but it was too damn nice to give it the BFPU treatment  Here's pics of my well-used Colt "4" marked A2 upper with shallow factory feed-ramps and a CMMG lower that I distressed.  I know I went a bit too far and bronze anodizing started to show

Double Tap

I kinda like the mismatched look (p.s. you double tapped!) :P

I like that receiver set. The cmmg lower looks pretty cool. Aeneas2020, your build was partly to blame an inspiration for my project.

Well i'm going to blame Morg and Pro2nd because I had no plans do to anything beyond making a cheap 22lr plinker until they got involved!

I only regret not snagging a few more uppers from that deal. I had "two of each" typed out and changed it to one at the last minute. Still plenty happy with this upper and the M4 upper.

the distressing job you did on that lower is one of the best i've seen, care to share your technique?

I went with 00 steel wool and 3M scouring pads in the shower  Don't tell my wife that BTW.  I took a little more color off than I wanted, but it's no different than some of the USGI lower's I've seen where grunts used a toothbrush dipped in CLP and sand for cleaning

Hahaha, now that's putting love into your weapon! Fantastic results IMHO.

And having stripped cosmoline from Nagant and SKS stocks in the shower without telling the wife, I can relate to, and respect your ingenuity!

I dig it.

+1 we really need to start a BFPU pic thread in AR Discussions.

That looks like you just grabbed it from Sgt. Ford on The Walking Dead.  So damn nice looking.  Very well done.

Thanks, all the wear is natural other than the stripped lower, I did that.

I don't know much about A2 but it looks like I've started a similar project.  I've got a "C MB" forge code upper receiver but I don't see Colt proof marks.  (Is it Colt?)  Stock has a "N" on the port door side, skinny hand guards and 14.5" M4 barrel from the barreled upper at top of pic.  A friend and I turned some spacers for the barrel, bead blast and cold blue and they look very similar to the modern barrel finish.  Delta ring had a few dings, I added more wear, worn A2 grip from the EE.  I could also use a 6720 barrel and I have a nice worn A2 flash hider.  The lower started out as an attempt to acid dip a black lower until it turned gray but I didn't like the way it turned out and I screwed it up a little.  If you look on the grip mounting area you can see where I tested the acid to see how long to dip the entire lower.  After the acid dip I assembled it and added some wear, one advantage to the acid dip is you can wear through the anodizing a lot quicker.  Questions I have are:

1. What would be the correct selector?


2. Is that the right style end plate?


3. Is that the right style castle nut?

I've got a 727 clone in the works (A2 carbine) . Nice collection of parts btw, love the beat up upper. the fiberlite N1 stock is correct for a "factory" Colt 727 carbine. if you want to get really on-point for your rifle, you will want a Colt CAR lock ring (the older version of the castle nut) which had a hole drilled in the side and aren't as thick. Not sure on the end plate though, just buy a Colt one? or use what you got. Maybe someone more knowledgeable than myself knows if there are any end plate differences over the years.  Original 727s had a 2-pos receiver extension but I'm rolling with a Colt 4 pos. (my preference). Don't feel obliged by any means to be 100% accurate or anything, throw parts together and see what you get, done it many times myself. Just post pics of the end result

 
 

Somebob,

Endplates are pretty much all the same, some variation on commercial ones but all colts are the same.

You will want an old style lock ring for sure , check with Bushmaster, they still had them a while back.

For the selector you want a deep v notch, you can get the from Armalite currently.

Two position tubes are correct and can be picked up from NDS but any 4 position will work(mil spec diameter) as the other holes cannot be seen, they appear the same as a two position from the outside.

These be some beautiful AR's postin in this thread.  Fo sho.

I called Bushmaster a few weeks ago to order some more old style lock rings. Sadly, they are no longer in production and out of stock. Stag selectors also have an A2-ish style tick mark. I picked up a couple for my A2 and 727 builds for around 10 bucks each

Small update, acquired a brand new take off 6920 barrel assembly.

What you really need is a 14.5" M4 profile barrel, not a 16". Even if you cut down the 6920 barrel to 14.5", it will not have the same profile as an original 14.5" M4 barrel.

Here is one from Numrich. It doesn't have the correct A2 flash hider but it is close enough.

http://www.gunpartscorp.com/Products/1503160.htm

should you want to go the 14.5 barrel route, you could do what I did and take a colt 14.5 and standard FH, email John Thomas and have him make you a barrel bushing so he can pin/weld it to OAL 16 inch. This way you won't need an extended FH (which IMHO don't look that great) and still have the "correct" barrel

 

It will be good enough for what I'm trying to accomplish. I also picked up a brand new Colt 14.5" SOCOM barrel but it's going in the C AF marked M4 upper I purchased along with the A2 upper. That will live on my 6920 M4 lower. Not truly correct clones, but good enough for me.

Can't wait to see that one finished. Excellent start.

Looking forward to seeing it.  A2 carbines are cool.  even with 16" barrels.  I'll throw this lil tidbit out there for you, for some reason I think when a carbine has a 16" barrel, it looks best with an A1 stock.  

^^^^ this

 

Here's what I came up with, I don't know what to think of it.  It is really tough trying to add fake wear to parts. I'm happy with how the delta ring came out but the lower and the buffer tube didn't work out like I expected.  The end plate and castle nut look to nice, there should be more dings in them but it is tough to do.  The flash hider is one I got off the EE, the washer has "real" wear and was found at a local show.  The sling has "real" wear and was found with ~3 others draped over the edge of a garbage can at a local show.  Barrel is Windham Weaponry I got off the EE, charging handle is a partially chemically stripped gray one I got off the EE, BCG was pieced together off the EE and with new little parts from DPMS or something.  It shoots fine, I don't know how to setup a proper target but I can basically hit what I'm shooting at along the back wall of a local former gravel pit.  On the right side of the lower there are circular stains around the trigger and hammer pin holes that appeared after the acid dip.  The front detent drain hole burned through because I didn't flush out the acid thoroughly / fast enough.  On the left side of the lower I'm not sure why it burned through in the FCG area.  It could be that there are flaws in the anodizing / dye from manufacture and the acid dip brings them out.  After the acid dip I put a piece of crap buffer tube in it and clamped a vibrating massage thing to it.  I wore leather gloves and handled the assembled lower (with a different beater upper) with locally acquired mud while it vibrated to get the smooth wear pattern.  It works but it takes an unbelievable amount of time to wear though.  I didn't get the wear pattern I wanted, I was going by pictures of deactivated A1 rifles on a German web site.  If I did this again I wouldn't do the acid dip but would use more aggressive mud, possibly sand blast sand.  (I don't know what kinds of media are available)  To add wear to the buffer tube I clamped the vibrating massage thing to a piece of junk stock and put mud / bead blast sand on the tube and worked the stock over it.  What a pain in the ass and it didn't end up looking that good.  Do To add scratches I drug it over a chunk of rail and other metal things.  (File down sharp edges first)  A2 grip was found on the EE and has "real" wear.  N1 stock has "real" wear and was found locally, trigger guard is new and I might have one with "real" wear to replace it with.  I didn't add any wear to the barrel, I figure it is a worn carbine with a replacement barrel.









http://s1127.photobucket.com/user/somebob/library/a2carbine?sort=2&page=1

ETA: Fix typo, remember where more of the parts came from.

Very cool!

I love it, definitely my favorite BTDT rifle that I've seen someone do.

It could use some more wear on the barrel and fsb, but other than that it looks beautiful!

hell yuh thats a sweet "been there" carbine

/\ what the 3 posters above me said

Thanks for the comments guys.  I've been asked how did I do this, here is what I have so far:

1)  If you want to acid dip it, I used some hydrochloric acid based drain cleaner and diluted the bottle about 8 to 1.  After testing the solution on the grip mount area I think I decided on a 3 minute bath.  I had the solution in a plastic cooler, washed the stripped lower with lacquer thinner while suspended from a piece of electrical wire in 2 places.  After 3 minutes I placed it under running water but didn't clear out the front detent spring bore well enough so it continued to eat through the drain hole in the fence.  Also, the buffer retainer hole inside the receiver didn't get flushed out well enough so it ate through to bare aluminum a little bit too.  The milled front edge of the fence by the front pivot pin wore through to bare at the sharp machined edge because the acid works on those edges faster than broad faces.  After the acid dip the whole thing was an uneven dull gray color with some unwanted finish flaws around the hammer pin hole, trigger pin hole, selector hole, and some light splotches on the other side.  I wasn't too happy when I dried it off, but as I added wear the problems got lost in the other wear / bare spots.  

2) Next I attached a cut up electric massage thing I got at a thrift store and attached it to a California compliant rifle length carbine stock I got off the EE.  I think there are other electrical appliances that would fit in the buffer tube but they were too expensive and I don't have anything like that lying around.  You basically have to assemble a complete AR to get all the right places protected from wear



Here is a "before" pic



Next, source some mud or other abrasive and handle it with leather gloves while the whole thing vibrates.  It takes a lot of work to break through the anodizing even when it has been worn thin by acid.  If I do this again I will use much more aggressive media than I did here.



Here is an "after" shot.



Along with the abrasion, try to get an equal amount of dings and scratches as the other parts.  It is really hard to do this.  I used a section of train rail and a big ship vice and rubbed the assembled lower against them progressively harder to get scratches and dings on it.  I recommend not using the same thing over and over to hit it, try to get a variety of different kinds of scratches in it.  Chunks of cement / a cement floor help too but they end up hitting the delta ring the most.  For this one I decided not to wear the barrel at all so I could tear it apart if I get tired of it, I think of it as a replacement barrel that just didn't get worn yet.




My original plan was to acid dip to get a gray lower so I didn't have to spend $200 on a NDS retro gray lower but it didn't work out well enough.  I wanted to then wear though to get an effect something like these.  If I try this again I'll use much more aggressive media.




http://www.zib-militaria.de/M16-A1-US-Colt-made-deactivated-assault-rifle-used-miltary-surplus-backstock-crack