While back I mentioned some Federal .300 Blackout ammo, the

190-grain Fusion tipped bullet.  Well, since my fancy little chronograph read it as averaging 160fps faster than the 1000fps on the box, I wrote to them and told them it seemed a bit hot.  

They wrote back and asked if I had any of the ammo left, if I did they wanted it to test and would replace it with a new box.  Sounded good, so it was done.  Today I took that new box and tried it out at the indoor range.  Three rounds* made holes just about touching, but the velocity still came out about 1165.  Which, according to the National Weather Service speed of sound calculator, comes out to be about 40fps supersonic there and then.

So it's accurate, but faster than it's supposed to be.  I still haven't found any gel tests on it, so no idea about expansion, though the Federal Fusion bullets have a good reputation.  Probably need to try them in someone else's rifle to make sure mine isn't giving a higher FPS than others.

Not the most scientific of tests, but thought I'd pass it along.  

*I wanted some to shoot at longer ranges so only used three today.  And that's not bad shooting for me, but I plan to do the longer ranges with a better rest.