I do that sometimes with my M54 Winchester .30-30 when I have the 12x Fecker mounted on it shooting cast bullet loads and am going for tiny groups and/or participating in a CBA (Cast Bullet Association) postal match. The load I use has been worked out long ago, so no need for a scale or bunch of dippers: 15gr. SR-4759/190gr. .310" cast bullet/CCI BR primers. Bullets all carefully inspected and weight matched beforehand too.
I use one case, formed from a .375 Winchester case so as to have a slightly thick neck wall, de-prime/re-prime, no need to re-size or trim, measure the charge with my Belding&Mull measure, thumb seat the bullet leaving it a tad long so it's lightly jammed into the throat when chambered. (Bullets have their noses lightly swaged in a die I made with the same 1½º included angle throating reamer I used to ream the throat of the rifle- a gentle taper that does wonders for starting a cast bullet straight up the spout.) If I'm in a particularly anal mood I orient the bullet the same way in the case (via a tiny mark on the bullet installed by a tiny punch mark I made in the mold cavity), and orient the case the same way in the chamber, again via tiny file marks on the rim and breech. It takes pretty much all afternoon to fire a few ten shot groups, but what's time to a pig?
Without going through all that folderol, using fixed ammunition loaded at home, the gun will deliver MOA accuracy, ten shots, or around 1½ MOA when using the aperture sights. By doing the one case for all shots routine, with the 12x scope, I can count on 3/4 MOA out to 200 yards if I dope the wind right (an important consideration even up close when shooting a 1400fps bullet). Not bad for an 85 year old rifle with an 80 year old scope.