I am the kind of person that looks at ever option to see what fits my needs and is the cheapest. Looking to get a SASS type rifle and I have had one on order for 5 months now. But I'm tired of seeing all kinds of DPMS rifles being in stock at diff places and the SASS upper being in stock but my rifle still hasn't come in yet. SO the wait has given me time to check into other options. This includes going with other brands to getting a diff model and then building it into a SASS. HERE is my question.....Can anybody tell me what the diff is between the 18" SASS barrel is from the 20" barrel on the LR308C? Besides the fluting and the two inches. I can get a LR308C and build it into almost what I want(fluting would be great) in the SASS for almost the same price as what I have my SASS on order for. Also as I understand it I can use the same trigger groups on a 308 as on ar-15?