Hello all,
I’m making my first attempt to build my first M4 and I could use some help! 
I picked up a DPMS upper today (I really want a Vltor upper) and just ordered a Sabre Defence barrel.
I was looking at the DPMS upper and noticed that it doesn’t have the M4 feed ramps. I could really use some tips on how to grind them in there, or would it be better if I just leave it alone? I’m pretty handy with a dremel so I’m pretty confident I can do the work. On the other hand all my magazines are Magpuls and I hear that it brings the rounds high enough where M4 feed ramps are not as important.
I’m taking the advice that I hear alot on this forum, so I’m picking up as many parts as I can, and the barrel I picked up just happened to be the only one in stock (I hope the inventory was correct). How does Sabre stand as far as quality? It’s a 1 in 7" twist with a chrome lining, it’s 16" long with flip up sights and Button Rifled (What’s this?). Would I be able to use 5.56 ammunition? (From what I understand 5.56 has more power than .223)
Is there any major difference between the Milspec and Commercial buffer tubes aside from outer diameter and rear profile?
Thanks ahead of time for your help, I did try the search button but I couldn’t find any solid information I was looking for.