Hey guys this is my first time to post but have been reading on OSA for awhile I have been wanting a ar 15 I have looked around but I think I want to build one haven't built one before so I thunk it would be a great way to get learn about the ar I have been looking at rock river arms the have a whole ar kit minus the lower for like 650 my question is can u really tell a diffrence I'm I diddnt use a rra lower compared to saw a dpms any feedback on this or any part of the building process would be great thanks