I like to fool around with slow loads in many of my guns. I have never done it because I was worried about barrel life, but that is as good a reason as any, and yes I have worn out quite a few barrels. I have slow and medium loads, quiet loads and full throttle loads for the 22 Hornet, 17 FB, 221 FB 223, and just about every other cartridge I shoot, including the 22-250.
It is part of the fun of reloading that a guy can build things like a 308 Winchester that shoots 40 grain round balls over 6 grains of Trail Boss, so you have chicken loads and don"t have to carry a 22 when big game hunting.
For real quiet and slower loads, Trail Boss is great, for downloading 4895 is great and can be reduced to about 70% laods very easily and 4759 makes great reduced laods too. The hogdon website has all the data you would ever need to cover off any of these. Never be afraid to experiment, carefully, no matter what your motivation to do so is.