Re: Subsonic for 700 sps tactical
The 150 flat nose 3030 bullets shoot very well for me subsonic. That or the 170s are worth a look for sure. The 180 round nose bullets work well too, but I have a quicker twist than you, so they may not work as well in your rifle. I would get a box of each and do some shooting!
You need a shorter bullet to stabilize it with the slower twist. Those heavy match bullets are longer, so they are harder to stabilize and will need a faster twist than what you have.