My guess would be about 750 to maybe as high as 825 from a 2" barrel. Normally, I've seen about a 100-125 fps decrease in velocity when going from a 6" barrel to a 2", but factors like cylinder gap will affect velocity readings. A tight gap will often give you a higher figure.
If you like the load and it shoots well for you, that's far more important than a power factor.
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