Mcmillan does not make tactical stocks for the 77/22 so no option there really unless you mod it yourself. Any 700 modal stock needs about 1/4" taken off the entire top and to have the action sunk into the stock by another 1/4" in order to get the trigger to fully protrude through the bottom of the stock. The action is much smaller (top to bottom wise) than a 700 or most other centerfire actions.
Best option is the small selection of aftermarket stocks which is not many and no really tactical feel or looking stocks... or mod your own from your favorite stock of choice.
The links above are going to be your best bet or a quick search of 77/22 stocks on the net. That, however small it may be, is your only options