Subsonic or Not?

[SDcollector]

I just bought a MP5 clone and I'll be using a suppressor after it's broken-in. There's a local gun shop that sells Sellier & Bellot 150 gr, 9mm ammo at a great price. I don't know if it's old stock, but there's no reference to it being subsonic. Every other source that sells this ammo has a higher price and it's actually labeled subsonic. Can I assume both are subsonic? Also, I've read some handgun owners who claim any 147 gr 9mm round will be subsonic. If true, would it still subsonic using a 9" barrel?
Thanks for any info!

[Sailormilan2]

The Speed of Sound is approximately 1125fps. The 9mm can get a 147gr bullet to close to 1050fps. That’s according to the Lyman 50th Reloading Manual, and using Power Pistol power.
The Winchester Reloading Manual doesn’t have any 147gr loads coming close to 1000fps. I don’t think the 9mm has enough powder capacity to get any faster.

[bcrich]

Definitely sub sonic in a 9” barrel

[Spyder]

Buy a box and see. Should be easy if it's a local shop.

If it's comparable price to normal target ammo, jut buy it all. Subsonic or not, heavier bullets > lighter bullets.

[SDcollector]

Thanks Guys!