Try shooting your ST 400's. You won't wreck them or the bow doing it. Chances are, they'll shoot ok from your recurve. If they don't shoot straight, then think about getting different arrows. The only problem might be if they are fletched plastic rather than feathers, and you shoot off the shelf. They may kick around a little. You won't have a problem pulling your recurve. The poundage builds steadily as the string comes back. The problem will be holding it back when you get there. You use different muscles than pulling a compound.