What's in your bag of tricks to squeeze the most potential from your 556? Each rifle system I have owned seem to have idiosyncrasies that when tuned properly had the possibility to dramatically increase the accuracy of the overall group size. Are there similar tricks that can affect the accuracy of the 556? I was considering tightening the gas tube to remove any movement and play, shimming the upper and lower receiver to tighten the fit and possibly switching the folding stock/brace mechanism out for a fixed assembly. Any other thoughts?