That Ranger ammo could very likely see someone court martialed. Hate to see that happen.
Generally speaking, at the echelon of most LtCol and higher, the M9's in the armory are in piss poor condition - as they're rarely fired (either in garrison, OR in combat.) The last time I ran an M9 range (just prior to leaving Kuwait), there were plenty of magazine failures, so indeed, I would replace the springs, and if possible get him some spares. The problem is, I wouldn't, and currently don't, carry anything in combat that I haven't tested. Lt. Col's, at least in my Brigade don't have a lot of time pre-deployment to get to the range - so that could very well be an issue. Other than the ammunition suggestion, I agree with replacement of major component springs. I can't comment on the locking block, and would leave that to the armorer (however incompetent he or she may be), before I went altering issued equipment. If on the range the pistol fails, or the armorer can't produce paperwork stating the appropriate maintence has been fielding, ORDER the thing fixed, or replaced. If not, and something *does* happen on a weapon that's been modified by someone other than the armorer, you're looking at nasty UCMJ crud again. Would it hurt my lowly E4 career a whole lot? Likely not, I'd be a Private again. Would it be a nasty smudge on an O5's record, quite possibly.
In short: springs, and keep it clean, and make sure you qualify with YOUR weapon (no pencil whipping allowed - it happens!)