This project started with the idea of building a parts gun around an old post ban Bushmaster 20" 1/9 HBAR barrel.  The idea was to use as many parts from the spares bin and cheap it out as a loaner rifle.  Well you know what happened, I just couldn't build a junker as hard as I tried.  Somewhere during the process I got off track, but thought it should still be sort of a "General Purpose" AR that could fill many roles.  So what I ended up with is the following:

UPPER
-Bushmaster chrome lined !/9 barrel turned down to .70 under the hand guard, cut to 18" and threaded by Adco.  The barrel was in new condition, having never been shot.
-YHM Phantom FH
-Mid West Industries low profile gas block.
-Blackheart International modular hand guard.
-CMT upper receiver.
-Smith Enterprises chromed BCG.
-Mid West Ind. BUIS
-BCM Gunfighter charging handle.

LOWER
-RRA lower
-DPMS LRPK
-Ambi Selector
-KNS non rotational trigger/hammer pins.
-Magpul enhanced trigger guard.
-Magpul Miad grip.
-CavArms A1 buttstock.

OPTICS
-Weaver 3-10x44, ballistic plex reticle, Armalite 1" mount.
-Leatherwood CMR 1-4x24, illuminated horse shoe/ranging reticle, Armalite 30mm mount.

Rifle Use



Self Defense Use




Overall the rifle handles and shoots good.  The barrel profile lightens up the front end and balances really well with the A1 length stock.  

The BHI modular hand guard is fairly light,  not having full length rails, and the rails are removable and mount in various configurations depending on accessories used. It mounts easily and is very solid, with a heavily checkered grip area machined in.

I choose to use a chromed bolt carrier group for ease of cleaning and maintenance.  

I think back up iron sights are a good addition to any rifle that uses optics for the obvious reasons.

Most of the other parts used are based  on personal preference.  The Magpul grip feels good in my hand and allows for a small amount of storage, the trigger guard just looks good.  The CavArms butt stock is A1 length, slightly shorter than an A2 stock and provides internal storage for a cleaning kit.

I like an Ambi selecter as it allows me to manipulate the safety with either my thumb or forefinger.

I had the KNS pins in the spare parts bin so I thought I might as well use them.  I've also found that if I polish the trigger/hammer engagement surfaces and replace the hammer spring with a JP reduced power spring, along with the KNS pins I can get a decent single stage trigger.

Bravo Co's Gunfighter charging handle is a must have if using optics.  It allows one sided weapons charging and is easily grasped under the scope.  Not to mention how sturdy it is.  My new favorite AR accessory.

The Phantom FH is more effective than the standard A2 FH, costs less than a Vortex and looks "cool".

ACCURACY
I didn't expect match grade accuracy from a 1/9 chrome lined Bushmaster barrel, and I wasn't surprised.  I shot 200 rounds of 55 grain FMJBT, both factory and my hand loads.  Average 10 shot groups were 2.25" @ 100 yds.
Ammo types used.
.
Groups were shot from a bench with sand bags at 100 yards.



55 grain Winchester

2.25" 10 shot group.


I tried shooting a box of Federal Premium 69 grain Sierra BTHP, results were no better, with groups again averaging 2.25" @ 100 yds.  I was surprised that point of aim didn't change between the different bullet weights.
5 shot group

10 shot group measured at 2.25"


The Weaver 3-10x44 scope has surprisingly clear glass.  The ballistic plex reticle looks just like the one used by Burris, only thicker.  Basically it's a standard cross with holdover marks on the vertical line under the horizontal line.  After zeroing at 100 yds. I was able to hit the 12" gongs at 100, 200, and 300 yds. consistently using the hold over marks.  The other optic I used is the Leatherwood CMR 1-4x24 with a  30mm tube and tactical turrets.  The reticle is interesting,  It has an illuminated green horse shoe and 1 MOA center dot also incorporating a vertical hold over scale and horizontal bracketing mils for ranging.  The illumination is dim in bright light but very usable in the shade or lower light conditions.  The glass is not as clear as the Weaver's.  The Armalite mounts allow quick installation and removal with two thumb screws.




So in conclusion I'm happy with my concept of a "general purpose" rifle that can be used for many tasks, from plinking, hunting, or self defense with just an optic and magazine change.  It's light, handy in size, and accurate enough with the most common type of 5.56 ammo available.

Nice looking.

Thanks

Cool rifle!!!

Projects like this make living in a ban state a little less painful.

I really, really like the handguard.

Real nice, I too like the handguard.

Very nice!  Great photos, and bonus points for having actually shot it.

Nice write-up!

Hey Guys,
Thanks for the compliments, I'm glad you enjoyed the write up.  The only thing I'm thinking about changing is the butt stock.  I've got a Vltor Emod in the parts bin I might try on it.  That would make it a little shorter collapsed, although I'd lose the cleaning kit.

That is nice. I wish I had a parts bin...

Very nice build.

The handguard seems kind of like a clone of the Apex CNC Machine one. Apex
http://www.prestoimages.net/store30/rd3738/3738_pd124272_5.jpg

It sure does, wonder if they're made by the same people, and marketed differently?

nice build

Great looking rifle and phenomenal write-up. IMO, the 18 inch barrel is optimal for a 223/5.56 general purpose gun.

I'm wondering do you know how Adco cut the barrel without chipping the chrome at the muzzle?  I have tried cutting FAL barrels several different ways and have never been entirely successful at doing with without at least a small chip.

I like it.    I think I'd rather have a shorter, or maybe adjustable stock on it, but that's probably all that I'd change.

Great lookin rig you got there!

Great looking firearm.

FALPhil-  They cut, thread and crown with a lathe.  I've had them cut/reprofile  several different barrels and have not seen chipped chrome lining on any of them.

Nice build, badass rail

I use my lathe too, and have tried several different cutters.  But I always get a chip.  With the high carbon cutters, the chips are very small, but I still get them.  I ahve had to do a lot of lapping to get them worked out.

Doesn't seem to effect accuracy much with this particular Bushmaster barrel.

Wow, that looks awesome. I dig it.

You did a fine job on this build.  It is a great looking rifle.