When I first turned 18 I went out and purchased an AR-15 to exercise my 2A rights. I wasn't a man flush with cash at the time, not that I am now either hehe, and went ahead and purchased a DPMS sportical. All in all, once equipped with sights, the rifle functions great (having dumped a few hundred magazines through it in 5 years or so) and have never had any serious issues with it. I have upgraded my rifle with a free-float Midwest rail system, all of the factory furniture has been replaced with Magpul upgrades, and some Yankee Hill bits here and there. However, as time goes on, and I become more interested in training to use my system, I have begun to realize the limitations of the basic sportical system... I was displeased with the prospect of having to procure a new upper half for a dust cover, shell deflector, and forward assist (costing in some cases 900+ dollars for one equipped with a rail system) until I realized, rather recently, that I could replace the upper receiver myself with a stripped aftermarket one. The one I have chosen as a potential candidate is the Vltor MUR-1a. I would appreciate any thoughts on this upper or other suggestions for uppers with M4 feed ramps. (maybe a place where I can find one :laugh Also, as I do not have a torque wrench, barrel nut wrench, vice, or the prerequisite skills I will need to go to a gunsmith to have this done. (any recommendations in the Lane County area/ a price guesstimate for the smith to preform the switch?) The last questions I have are regarding the barrel of the Sportical. I know it (the sportical barrel) has M4 feed ramps but is there any other variable I need to be aware of when selecting my new stripped upper? Also is it possible to replace the gas block, the one I have is really chunky and wiggles around a little ( likely normal, but it makes me worry I may loose gas sometime when I really need it...) Any input is greatly appreciated.