Supressor speed increase

Whats everyone seen for velocity increases while adding a supressor? I have one of the old magnetospeeds that you cant check velocity with a can on, but according to down range dope ive estimated it to be about 30 fps increase.

Has anyone tested this side by side with and without a supressor and got an actual number?

I get about 15fps on a 223 and a 300wm. two different kinds of suppressor shot over a 35p.

With my 6.5 SS and a .30 cal Ti huntertown arms can I only saw a 3fps difference over a magnetospeed with 3 shots.