I looking for some advise.  To start off I am not new to guns.   I have several handguns, rifles, shotguns ranging from .22 up to 308.  This is going to be must first venture into the high capacity semi auto rifle.  I have a budget of $4,000 (wife approved since I haven't purchased a gun in about 8 years) and I was wondering on advise on how I am planning on using it.

I have been looking at PSA and Anderson for a base

Complete lowers  roughly $160   3 of them $480
20 in upper   $450
11.5 in uper   450
supressor $600
Tax stamp  $200
20 pmags     $180
2000 rds   $700

That puts me at $2,600.

The plan is to have a 20 inch full rifle and a smaller ar pistol with suppressor..   I would also have a lower to build on later.   I have a few questions.

Optics.   I have been flirting with going with an acog.  It is very expensive ($1,000 is the lowest I have found).   Is it even close to be worth that kind of money?  Is there a different optic that would be cheaper but serve my needs?  Red dot on the pistol plus a brace possible.   Also I can't seem to find 20 inch uppers in stock anywhere but can find 16 inch everywhere.  Are 20 in more rare or high demand?  Thanks for any imput

You're going to find a lot of guys here that love ACOGs. Personally, I'm kind of blah about them. To me they're a middle ground optic that does nothing well, though they are robust by all accounts. They have too much magnification for CQB and not enough to help you when the distances start stretching out. I can understand the need to fill this niche in some combat operations, but for most of us I think either a high quality variable power scope or a red dot is a better option. I may get flamed for this opinion shortly. Both of my rifles wear Aimpoints. The truck gun has a PRO with the Aimpoint mount, my "pet" rifle has the M4s with a LaRue mount. Long shots can still be made with a RDS in the unlikely circumstance you find yourself in a long range gunfight. Plus the M4s with the LaRue mount can be had for $800 or so (less with the standard mount) and the PRO (also an excellent optic) for $400 or thereabout. Leupold makes some nice scopes if you're looking for magnification, and some of them like the Mark AR aren't too badly priced. There are many other options as well, ranging from Walmart Centerpoints to $3-4000 German glass and everything in between.

20 inch uppers aren't as common as 16 inch ones, which is likely why you aren't seeing many. 16 and to a lesser extent, 18 inch are all the rage these days. Lots of guys are building SPR/DMR clones with 18 inch barrels.


 

Why do you want a 20"?  It's pretty much outdated.  It's cool for retro shit, but have fun carrying that thing around.  I'll take my 16" recce build over a 20" any day of the week.  Is this for accuracy?  If so you're better off parting something together

You have a very nice budget.  However you are going for quantity over quality.  If it were me I would build a really sweet 16" build, and then a cheaper pistol build.  I'd go with a 1x6 variable scope over an acog, you need to get quality parts right now vs insane optics.

The 20 in upper is for accuracy.  I might do an 18  instead for the same reason.   I am really interested in a more full sized rifle vs a carbine..   I was really wondering about the Acog and I think I may have my answer.  I thought it seemed really pricey because for that money I could put a pretty good optic and mount on the rifle and a red dot on the pistol and still have money left over.   I might look at saving some money there and putting it towards a better upper.  What would be considered some mid tier 18 in uppers?

You're short a stamp.  One for the can, one for the 11.5 upper.

And you'll want a Geissele trigger.

While length is important, I think a better thing to focus on would be a quality barrel.  a 14.5" or 16" Larue will absolutely outshoot a milspec 18 or 20" style barrel.

You're not going to get accuracy just because it's a 20" or an 18"

I don't think I need one if I build that upper as a pistol.  Forgot all about a trigger.  Thanks for the reminder

 

Thanks for the imput.  I am going to need to refigure the builds

Ah.  Missed the part about the pistol.  

You might be flirting with a charge of "constructive intent" to "make" an SBR merely by having a rifle lower in proximity though.  But I'm paranoid when it comes to our untrustworthy Justice Department, since my name doesn't end in clinton.

If you're really looking for a precision build it would be in your best interest to build an upper yourself.  Piecing parts together. I'd suggest a Larue barrel since they are on sale at the moment