Two Questions for AR-15 Aficionados

[Black Butte]

I am navigating the path toward my first AR-15 build, and two questions have presented themselves:

(1) I would like to have a bolt carrier group that is as close as possible to being an authentic representation to a true military M-16 while still being completely legal. It is my understanding that certain models of lower receivers and bolt carriers have "features" machined (or not machined) into them so they cannot be modified to fire three-shot bursts or full-auto. What brands and models allow for an unadulterated, non-neutered bolt carrier which can be used with civilian disconnectors, sears, etc. to produce a more accurate semi-auto AR-15 with minimal differences between it and its military counterpart?

(2) I was looking to go with a 16" mid-length gas-system barrel with a front sight post. I do not, however, want to be in a position where I have to drill the holes through the barrel for the front-sight tapper pins. An ideal barrel would be one for which the front-sight post has not been installed so that I can put on a one-piece free-floating handguard. What barrel would you recommend that has the holes for the tapper pins pre-drilled, or is it the case that you buy your barrel without them and have a gun smith drill the holes? Being in a state that is not "gun-orientated," my access to competent smiths is limited, unless I send the barrel away or have the work done in-house from whatever vendor you guys suggest. I do like the look of some of the fluted barrels, like the ones Yankee Hill markets, for example.

Thanks for chiming in guys (and gals).

 

[cbrgator]

This will answer question 1:

http://www.bravocompanyusa.com/CMT-M16-Auto-MPI-Bolt-Carrier-Group-p/bcg-cmt-mp-m16.htm

http://www.bravocompanyusa.com/LMT-Bolt-Carrier-Auto-M16-p/bcg-lmt-m16.htm

http://www.bravocompanyusa.com/Daniel-Defense-Bolt-Carrier-Group-MPI-Auto-M16-p/dd 9300.htm

 

[flynlr]

colt ships most of their non military market rifles with FA bolt carriers identical to the MIL models. many other MFR's sell Mil spec bolt carriers. Spikes,BCM come to mind. as far as lowers. I think you are looking for Low shelf lowers. CMMG and again Spikes come to mind,others are out there I'm sure.

 

[Black Butte]

Thanks, Cbrgator. Exactly what I was looking for. Bravo Company USA was sold out, but I'm looking at the Daniel Defense bolt carrier group sold by AIM Surplus for $129. It has the same DD9300 part number as listed on Daniel Defense's website but for $40 less.

http://www.aimsurplus.com/product.aspx?item=XDD9300&groupid=55

Now for the barrel ...

 

[mtrmn]

It's OK to have the M16 BCG and lowers that have not been modified to thwart tampering, but that's about the limit. If I understand correctly, it is a major no-no to have in your possession even 1 piece of a full auto fire control group without the proper documentation. So if you were ever thinking of maybe doing a little fine tuning of your own in the future I'd strongly advise against it. Just some friendly advice in case you may be tempted.

As far as drilling the holes for the taper pins-I think the holes are tapered as well and would be a challenge for anyone other than a machinist. Get a barrel that already has the A2 sight installed and drive the pins out (left-to-right I THINK) to remove the sight. No big deal to drive them back in from the other direction when you're through working on it. OR just get a clamp-on gas block and taper pins be d#%%^d. The clamp-on gas blocks will also hide the taper pin holes nicely if you decide to switch gas blocks later.

 

[fatcat4620]

I have not seen the front sight your looking for that does not use taper pins. I know YHM makes all sorts of bolt on front sites.