Sunday, January 25, 2015

Building an AR-15 from Scratch

I've had a Stag Arms stripped lower receiver sitting in my gun safe for about two years, and I finally decided to build an AR on it.  I have an A3 and an M4, so I wasn't sure how exactly I wanted to build it.  I thought it would be neat to build one that could do some precision shooting, maybe out to 250 - 300 yards or so.  Not a "sniper rifle" exactly, more along the lines of what a squad designated marksman might use.  I started looking on Gunbroker and eBay, and it wasn't very long before a tidal wave of packages began arriving at my house.  I tried to save a little money here and there, but I was determined to only use quality parts.  If the rifle was a patchwork of good parts, than so be it.  I found a stripped Noveske upper receiver at a good price.  I found a really nice 18" spiral fluted heavy barrel on eBay, believe it or not.  I found a like new Bushnell 1-4x scope and an SWFA mount.  I found a good buy on a Hogue floating hand guard -  at less than half of what it would normally go for.  It was like a scavenger hunt for about three weeks.  I admit, the rifle's a mutt.  There's probably at least one component in it from any major AR brand you would care to name.  I kept thinking of that old fast food chicken nugget commercial, "parts is parts."  Also, the Johnny Cash song about the car he put together from stolen parts over a couple of decades kept playing in my head as I assembled this pile of springs, pins, and forgings.  Gee, I hope this thing works. 

My first range outing with the rifle was somewhat disappointing, because I had apparently not bore sighted the scope properly and couldn't even get a hole in the paper.  The good news was that the rifle functioned perfectly - that was indeed welcome news.  After correcting my hasty mistake, I took the rifle back to the range and managed to get it zeroed first at 50, then at 100 yards.  Then I settled down and tried to see what I could do with the rifle.  I was very pleased with the results.  Again, the rifle functioned flawlessly, and it produced some reasonable groups when all aspects of its composition are taken into consideration.  Allow me to elaborate on this.

The first thing I noticed was that the 1-4x scope I had put on the rifle was barely adequate.  At 100 yards with four power dialed in, you can see a big black circle, but not enough detail to do anything except aim for the center of mass.  It's a big improvement over iron sights, but that's about as far as I'd go.  I am absolutely convinced that the rifle could shoot better groups with a more powerful scope.  A 3-9x would probably be about right, but I think it could make good use of a 12x or even an 18x scope.   The rifle is certainly steady enough to use most of that magnification, with its bipod and rear monopod. 

The other aspect that seemed to cry out for improvement was the trigger.  I built the rifle with a stock Stag Arms single stage trigger.  There's nothing wrong with it, mind you.  It's actually a really nice service-rifle type trigger.  It lets off very cleanly, with no discernable creep.  However, after firing a few groups, it occurred to me that a good, national match, two stage trigger would probably make a world of difference in what the rifle could do.  It would afford that small but very important improvement in the ease of release, and would probably tighten those groups up noticeably.

 Fortunately, these two issues are both easily fixed.  At some point in the future I will undoubtedly mount a scope with greater magnification.  I like the Bushnell drop zone AR scope that is on the rifle, and I'll probably replace it with another scope from the same line.  Bushnell offers a 3-9x, but they also have a drop zone scope that is 4.5-18x that is very intriguing.  Do you really need all that magnification?  Maybe not, but you can always back it off.  It would sure be interesting to see what the rifle could do with it, in any case.  Similarly, two stage match triggers are readily available and easily installed.  I'm not familiar with all of the brands that are available, so I'll have to do some research on the internet before I settle on which one I want to put in the rifle. 

While I was cleaning it, I reflected on the two year lapse, and then the furious three week parts acquisition frenzy that culminated in this great rifle.  A year ago I would have probably built it differently.  Two years ago, perhaps differently, still.  Nevertheless, as AR shooters are fond of pointing out, AR's are like Barbie Dolls for men:  if you don't like what it looks like, it's easy to change it.  Despite the shortcomings of the scope and trigger however, I'm very happy with the way my AR turned out.  It functions well, shoots well, and most importantly, it's a lot of fun.