Things they don't tell you about building an AR:
You have to know just what you're #1 task will be with it, and stick to that type. M4geries with 3x9 variable scopes are at cross purposes - the weapon type is a short CQB carbine, the optic a long range precision target or hunting type. It can be an ok shooter, but it doesn't do either job well. You can't rockcrawl a Cherokee with 22" dub rims and 35 profile race tires. Stick to the accepted types because they were done that way for a purpose.
Most of the photos on the net aren't posted as a tutorial of what constitutes a good build. It's an exercise in "Looky what I own." It's better to pay attention to what shooters use, military, hunting, three gun competition, and again, stick to the type, don't cross fertilize. German shepherd head with Dachshund body isn't where you want to go.
Costs ramp up just like a government project. Substitute one good simple milspec quality part for a whiz bang hi performance one and the money flies out of the wallet. The return for the "investment" is much less per dollar, and sometimes may never be seen. NM, competition grade, or extreme duty use need to be the end goal to justify the extra money. The builder also has to have a realistic appreciation of their skill level - building a 1/2MOA shooter that can survive 50,000 rounds of high power ammo is more of an indictment of silliness when the gun is shot for a hundred rounds every month or so.
This gets directly to the M4 fad currently going on, and what's wrong with it. Many of them sold are carbine length gas, which is wrong for a 16" barrel. Carbine gas belongs on a 14.5" registered or Govt owned weapon, midlength is the correct gas to use for a 16" civilian gun. The adjustable stock is cool if you need to wear body armor, a recreational shooter is better off with the much less expensive A1 or A2. This also nets a rifle length buffer setup with smoother function, and near zero bolt bounce issues. The gun will shoot smoother and get back on target quicker, with less drama. 5.56 isn't a recoil problem, but for quick competition shooting, don't set yourself for more recoil if you don't need it.
Get regular handguards, the quad rails are an institutional answer to various users needing to clamp on all sorts of hardened gear with old style battery power. Very few ever need 48" of rail or use it, single strips do the job right where you need them. Ladder covers to keep from tearing up your hands are needed, and prevent snagging anything they could have tangled in. Handguards avoid all that. Some complain the front sling will move the point of impact if used, and the answer is don't use the sling! Nobody shoots barrel mounted slings with tension for accuracy, the need for a free float is really an admission they don't know what they are doing. Using a high precision range technique on a battle rifle is some of that cross fertilizing again, you get weird results.
Put the $300 - 450 dollars saved on stocks and quadrails toward quality parts and a good barrel, you will shoot circles around the tacticool gamers out at the range.
That leaves more money for an optic, which do a better job for the 400m max typical shooting. You don't need a milspec $650 - 1,200 type - the overbuilt expense and lack of seeing a dot thru the front lens won't be missed. The front runners also have components coming out of the same factory in China - yes, China - as the $250 optics. They just don't want anyone to know, but it's coming to the public's knowledge. Unless you have life and death on the line, the $250 optics will do the job nicely. If you are in daily contact, Murphy happens, the good optics still have glass lenses and break down, back up sights are practically mandatory anyway.
Don't let the comments about pay once, cry once go too far. Folks are honestly trying to steer you to quality products, cheap ones don't have good service life, and replacing it means you paid in full and may still have a problem child. Those that absolutely insist that nothing less than XX will do are pushing a different agenda. They likely have ego on the line, and need the support mechanism to justify their lack of thinking through to a different conclusion. And as always, let the buyer beware.
Even then, within a year or two I'd end up replacing this or that and accidentally void the rifle. I'm just not one to leave things alone.
