I have a SGL31-62 on layaway, and a SGL21-63. I have already sold my 7.62 ammo and mags to find 5.45 mags and ammo. I am debating if I should drop the 21 and go all-in with the 31, maybe even buying 1 or 2 more this year. I have never shot the 5.45, so I don't know what to expect, but my teen son wants me to buy one for him to have someday. WWYD?