Build or Bought: pay more, get more


Unicorn hunter
Apr 25, 2018
I love project guns.

I build whenever I can and specifically with ARs I think a great argument can be made for building.

I just ran the numbers on my latest Aero M5E1 (LR308 compatible) AR build in .338 Federal and came up with $1,100.

That sounds like a lot compared to an off the shelf Aero or PSA but the thing you miss with that comparison is that mine has nearly every piece upgraded in some way.

I have a free float handguard with a solid attachment to the upper rather than the barrel nut. I have an adjustable gas system. I have a drop-in match trigger with top of the line anti-rotation pins. I have ambidextrous magazine release, selector and charging handle. I have a high quality buffer tube with anti-tilt feature. The stock and fin-grip aren't terribly fancy but they fit the legal requirements I have in California. It's a much different gun than what I can buy off the rack.

Some people might run the numbers on buying a PSA and upgrading the same parts but at the end of the day it's a PSA and the handguard won't be as good since it has to clamp to the barrel nut.

You could also go to Wilson Combat where I bought my 338 Federal barrel and find a complete 338 Federal from them for $2,000+, then look them over to try to find exactly which parts are better on a Wilson Combat. I don't see anything significant, some Wilson Combat parts just cost more than buying good or better parts when they are on sale.

Of course building with bargain parts requires three things: time, tools and building it.

It takes time to wait for sales and piece together what you need. Get on email lists, you'll receive coupons and hear about sales first so hopefully the good deals are in stock when you look. Make a wish list so you know what you want, what a good price is and acceptable substitutes.

Pay attention to which parts never go on sale, free shipping promotions and taxes. Some times you'll want to pad an order with an ok priced part that never goes on sale to qualify for a free shipping promotion or just to avoid that one last order with $9.00 shipping for a $20 part.

The tools to build an AR lower are pretty simple. The only ones I've bought are a castle nut wrench for carbine buffer tubes and a long T25 security Torx bit to use as a roll pin starter punch on AR15s (not required for large frame ARs).

To build an Upper it gets more expensive. Some people use a lapping bar to ensure the barrel seat is square to the receiver bore. A clamp to grab the upper by the takedown pins or top rail is required for torquing the barrel nut. The Aero enhanced uppers come with a barrel nut wrench that will fit on a breaker bar. On an AR, barrel nut torque isn't a huge deal because it has no bearing on headspace. The specs give a very large range so don't get too concerned if it needs to be a little less than you were expecting and don't feel the need to torque it super tight if things don't line up exactly right.

To actually build it, you need probably a workbench with a vise, a little bit of enginuity and the tools I mentioned previously.

Some well planned builds fall together easily, some might need a little gunsmithing with a file or occasionally a bit of polishing with a Dremel. Some builds with big incompatibility might need real machining to get it working, try to avoid that.

My last Aero M5E1 fell together even though nearly every part is a better than basic upgrade and the only things that match are the receivers, handguard and a few parts from the LPK.

AR15s are even easier except for the roll pins.

I've probably spent $250 on AR tools spread over many builds but that's several barrel wrenches, a panther block, a PRI clamp, two reaction rods, receiver lapping tools and a tiny adjustable reamer for custom fit oversized takedown pins on LR308 type ARs. You barely need any of that to do one. Amortized over many builds, the cost is minor (but a smart application of buy once-cry once could have reduced some of my duplicate tools).

Buying name brand premium ARs instead would have cost a lot more and ultimately reduced the number or quality of ARs I could afford.

If you want to find deals for an LR308 type build:

Schuyler Arms (wait for a sale), Optics Planet (try to stack a coupon on a sale) and occasionally Aero Precision direct (Black Friday and other sales) are where I buy my Aero parts.

WC Armory is where I buy Toolcraft BCGs.

POF occasionally has 15% off sales and I use that to buy their P308 7 position carbine buffer tube and buffer spring. It's an AR10/Vltor A5 length tube, I'm pleased with the quality and it has an anti-tilt feature. It's pretty much the only POF part I buy but it's a good one.

JSE and Midway USA occasionally have good deals.

Wilson Combat sometimes has deep discounts, my .338 barrel was 50% off.

I'm sure there are other retailers that have good deals on one thing or another but those mentioned have worked well for me.

My ARs that I started working on about a year ago are coming together now. They all have the upgrades and ergonomics I like and I think I can count on my fingers all the parts that I paid regular price.

Some people belong to the "Go be poor somewhere else" club and that's fine if you have the money but you can also take the same money and build a rack of damn good ARs instead of buying one from KAC.

It's easier to do when you already have a few, it doesn't make much sense to take a year or more to get your first AR together and it's good to figure out what you like and don't like before you build.

If the situation is right and you are handy enough, build!