Don't know what that had to do with the question but, that guy is obviously a booger eating moron, with little concept for the bill ofrights and it's guarantee of individual rights. as well as contradicting himself on a militia at to regulated or unorganized he seems like just the right guy for anti gun folks to send their money to.
Yes. Barrel/Extractor change. Personally I wouldn't though just cuz 10mm is a beast and I'd rather keep my 21 in carry rotation without mods. Also I heard a rumor 10mm is gonna go away in Glock so would be a good investment... I'll try to find the source on the rumor but ymmv