DANGER, Will Robinson!
That's not a good load for several reasons: One is that many powders, and slower rifle powders and spherical types in particular, produce extremely erratic pressures below around 60-70% case fill. AT 25 grains you would be at 43% fill, right in the middle of the worst part of the curve. Norma has shown excess pressure being developed under these conditions with some of their powders. Not worth the risk.
Another is that the predicted pressure is so low (about 5,000 psi) that there is a good chance, too, of loads squibbing out and leaving a bullet stuck in the bore. If you fail to notice a stuck bullet and fire a second round into it, a bulged barrel is a real possibility.
In addition, that pressure is so low, even if it did burn in a repeatable fashion, it would burn so inefficiently that you'll find a lot of fouling and unburned grains all over the place. The cases are unlikely to seal the chamber well, so you can expect fouling getting into the chamber and falling down into the action. You'll likely find primers backed out for lack of pressure to reseat them.
H414 is just way too slow burning and is an inappropriate choice for what you are trying to do. 12.5 grains of Unique, which won't care about the extra empty space, will give you better cast bullet performance at half the cost per shot. 16 grains of Trail Boss will perform the same as the Unique, but fill the case better, burn much cleaner, and probably be more accurate (though you'd have to try it to see).
