Pretty much all of mine is handloaded except .22 Rimfire. I buy match bullets for most of the centerfire rifle shooting I do, but cast my own for handguns and some rifle loads, like .45-70. New ammo is something I have some of, but typically only buy it if it's very cheap and in order to get reloadable brass for something, or if it's the first few rounds for a new (to me) chambering to try the gun out. I've pretty much stopped shotgun shell reloading as it doesn't seem to save much money and inexpensive shells come around every fall that are good enough for the small amount of shotgunning I do.
Some, including most notably Masaad Ayoob, feel it's prudent to use commercial ammo for self-defense from the standpoint of not confusing CSI's with the unfamiliar evidence and not giving a survivor or the relatives of a deceased perpetrator an excuse to sue you, as handloading for self-defense might be argued by some attorneys as indicating blood lust. These are not factors tracked in legal publications, so nobody really knows how much it actually matters, statistically. Do whatever you are comfortable with in this regard or check with your county prosecutor's office to see if they care or not. I think mostly you'll find they don't care if you used a handload, a battle ax, or the kitchen sink, as long as its use was justified and the nature of the weapon is not illegal (poison-tipped or explosive bullets, that sort of thing). But some may be funny about it, I suppose.