I have been shooting BB 3" 1550 fps loads through my FIXED choke Remington 870 for at least fifteen years running. And I shoot quite a few rounds a year - at least a couple hundred. No problems yet. The screw-in chokes are SUPPOSED to be stronger so I would imagine you will be okay. The only concern I would have is whether you will get the pattern that's useful for you. Blackcloud is still steel. It's not hevishot. So sixty yard shots are way out there for steel even if you can stand the punishment of 1550 fps loads. I'm thinking for standard forty to fifty yard shots which really are steel's peak performance, the pattern through that full choke is going to be pretty tight. Put a load onto paper and see what it looks like. That's the only way you'll know what's best for you. If you can't get a target with a goose illustrated on it, do your best to draw something of that dimensions. That will give you the info you need. I suggest going on line to get the waterfowl paper targets. The shipping would be negligible.

Modified is better but yes my fixed choke is full. I would be better off getting it bored out to modified. This fella has choke tubes not fixed choke.