I'm as green as it gets to black guns, so a little insight would be great. I want to buy the Sig p556 Swat (new), looks good, respected manufacturer and it's easy to make an SBR. I plan on owning an SBR and this is my favorite pick so far. But....this is my dilemma:huh:. I just ran across an opportunity to possibly buy a Colt M4 (used) with accessories for a very nice price. What would be the better 5.56/.223 rifle buy? SBR either and it's going to cost me $200 regardless. I can always get the Colt M4 now and the p556 later, but I'm just looking for personal opinions and facts. Thanx!