What would be a good scope for a 300 Blackout for shooting subsonic and supersonic ammunition? Up to 6-8x maximum that is somewhat calibrated for the 300.
It is impossible to "calibrate" one scope for both supersonic and subsonic loads.
It is an SBR, a good dot sight is about all you need.
These are close range guns and they aren't precision weapons.
If you really feel the need for magnified optics, then a good 1-4 will suffice.
Yeah, I went with a RDS due to the aforementioned reasons fdkay mentioned. I have a 8.3" 300BLK SBR I run suppressed with supers and subs. The subs i dont feel confident with past maybe 100 yards, just too much drop, the supers are good to about 300 yards.
I use a Vortex Viper pst 1-4 on my 8" 300 blk, I like it because it has hash marks every 2 moa so once I got my dope of supers subs I can shoot anything at any distance.
The 300 blk specific reticles are expensive, and they may not match up to the ammo or bullet your barrel likes.
I've had several on my blackout. 2-7 Nikon x6 Swfa 1-4 PST. 1-4 Leupold pig plex. After this hunting season I've settled on the Swfa 1-4 mil mil. Zero your supers at 100. Dial up 2 mils for you subs to be zeroed at 50. Very easy to use clear glass for 299.99 . Tracks great.
There are some good deals on the Steiner P4Xi with free mount that I would give strong consideration too.
For the realistic ranges most have with this cartridge, I don't see a great deal of advantage for higher magnification or cost. There are specialized cases for something else but, for me a RDS works good enough but, a bit of magnification is good for longer shots on Coyotes (within reason of course ).