As a side note on measuring barrel length: Do what the ATF does, which is to close the bolt forward in battery, insert cleaning rod, mark with a Sharpie where the longest part of the barrel ends, then take the cleaning rod out and measure that. That is how they test overall barrel length and it had better be 16" or longer. Of course if you drill, pin, and weld then your muzzle device becomes part of the "barrel" and is now counted in the overall barrel length. Word to the wise: simply using Loc Tite, super glue, or any other temporary method of affixing the muzzle device does not constitute a "permanent" addition to the barrel in the ATF's book. I've seen WAY too many customers come in the gun shop with crazy ways of attempting to do the 14.7"/muzzle device thing. Know the law, stay out of club Fed.