Years ago I bought an AR in an 11.5 pistol. I put about 2 mags through her , and shes been in the safe ever since. Over the years I have ended up with a few extra pieces, But Today The UPS man brought me a 18"WOA SPR barrel. I had completely forgot about it since it had been order 5 months ago for another build, and said build was sold due to lack of components. Now the problem, do I use the pistol for a new build or sell, and start fresh?