Colt Ar-15 Match Target Comp. 20" barrel... I want to upgrade and have no idea where to start.  The world of ARs is new to me.  It is a standard production MT6700.  I would also like to replace the stock front arms but with all the choices I am lost...  

I would guess that there is something that can replace the front sight that will hold the existing arms in place so that a scope can be mounted with out issue.  Do they have front sights that fold up that can replace the existing sight?  Any suggestions?

One other question:  On the barrel it says Cal. 5.56 NATO. but the gun is .223.  I understand that the 5.56 NATO is the mil spec of the .223 and has a little more punch.  By running the 5.56 am I going to have any issues with this gun?

Please...any help would be great.

Thanks
Zackeal

At the risk of getting my butt handed to me, I will attempt a clear answer. The Rem. 223 and NATO 5.56 are two different rounds. The 5.56 is a military round and the .223 is a civilian found. The case in the 5.56 is made a little heavier in places and the case neck is not quite as long as the .223. This COULD cause the bullet of a .223 round to be forced into the rifling of a 5.56 on chambering and cause higher pressures on firing.
The .223 can be fired in a 5.56 and a 5.56 can be fired in a .223, but, except in cases of emergencies, I would avoid it.

Cut and paste from the Ammo Oracle.

Dimensionally, 5.56 and .223 ammo are identical, though military 5.56 ammo is typically loaded to higher pressures and velocities than commercial ammo and may, in guns with extremely tight "match" .223 chambers, be unsafe to fire.

Oh just read this instead. ammo.ar15.com/ammo/project/hist_diff.html

Okay...  just so I am clear.  If my barrel is marked 5.56 then I should be good to use the NATO round correct?  Even if the lower says .223.  I will likely never use the NATO round but just in case it ever comes up......

Yes, your barrel is where the chamber is cut, not the lower.

Anyone willing to tackle my other questions?hinking.gif