Re: 45acp sub sonic
Short of the light (145/155/165gr) semi wad cutters that are loaded up and pushed hard to make major in IPSC I don't think you will find any supersonic 45 loads. Speed of sound is nominally about 1125, you are usually flattening primers by 1100.
If it's a factory 45ACP it probably won't be SS, and if it's over 185gr it will probably blow up before it gets there.
<span style="font-style: italic">edit: Assuming we are talking about a pistol with a bout a 5" barrel. If you are shooting a carbine then the possibility may be there.</span>