I use nothing but CCI standard velocity in mine, which is what you will hear a high percentage of the time on this forum. However, some owners have called S&W and have been told that HV ammo will not hurt it, and truth be known, when I first got mine, I shot a little of everything in it. But I had a lot of stove pipes and FTE's when I was shooting the other stuff. I then tried CCI SV, and have been problem free (as long as the gun is clean enough) ever since.
If you do shoot HV ammo and it functions OK, you might want to consider a recoil bufffer or other springs, which can be bought in the aftermarket. I do think that one thing makes a lot of sense; that is, why would you want to shoot HV ammo, when it's usually not as accurate and causes more wear and tear to your expensive target pistol?
If the HV ammo that you have functions acceptably in your gun, I think I would shoot it, but when its gone, change over to SV. (Just my humble opinion!)
I buy CCI SV at Dick's and it is currently priced at about $28/brick, which I find within reason.
kas