Blackcurrants - planting then moving?

Octoberish would be fine. That's the time of year you move the previous season's cuttings.

vineweevil1,
A friend of mine has given me a pair of blackcurrant bushes in 4" pots.
I've transferred them to 12" pots, with a mixture of soil and general-purpose compost, where they will spend the next 3 or 4 months before being planted in their final position in September or October.

They are best planted early winter, and like plenty of well rotted manure or compost in the planting hole which should be dug deep and wide enough to take the roots without cramping them.
Plant them deep; a couple of inches deeper than they were in the pots; and firm in well after transplanting.