I have owned and built many AR15 .223 rifles and have also owned 2 SR25 .308 rifles in the past. My question is, What kind of problems am I going to run into once I am out on the range and shooting it for the first time? I went into a gun shop this weekend that had many, many, many AR15s and parts for ARs. They were very knowledgable about AR15s also. But, when I asked the owner what he had for AR.308 parts, he said he would never own one, nor ever carry parts for one. He said they are nothing by problems and they never function properly? Well, I don't really think he has delt with current manufactured guns, but not sure. I have not heard anyone say things like that on here either. What is your opinion on this? I don't think it is going to be a problem once everything is set up right. Does an adjustable gas block help with the function of the whole gas system on a .308? Anyone with solid experience please chim in here. Thanks a bunch!