Only if you originally upped with ords.
Example: I up a P-51 with 100%, 1k's and rocks, use up and return. Rearm: I opted to leave bombs, take only 50% but keep rocks. Use, return; Rearm: I put bombs back, take 75% but no rocks. I can do this because originally I upped with all that stuff.
Example2: I up a 51 with 50% fuel, no bombs or rocks. Rearm: I put 100% this time, but can't load bombs or rocks because I didn't up with them in the first place.
Example3: I up a 51 with 75% and bombs, no rocks. Rearm: I drop to 50%, leave bombs but can't put rocks on because I didn't up with them in the first place.
I think I've established my point.