Define Springfield musket..
A rifled Enfield runs about .577.
Springfield smoothbore musket run about .69.
Springfield rifled musket run about .58.
So ,you could run an .577 Enfield bullet in a .58 rifled Springfield no problem( in theory , would want to be sure weight and design are "normal" for use ,and not some oddball.)
As to typical 3-ringer ,we need size of the three ringer. Could a three ringer be used in an Enfield. Sure if it fits. Better if hollow based. The skirt on a hollow based minie type bullet flared on firing to take up slop (within reason) and seal the breech gasses to propel bullet. An oversized bullet would be a pain to load while deforming it.(Snug is one thing ,too tight is another) Worse with a fouled bore. Solid base were not as convenient to load in a fouled bore. And required a good/stout charge under it to upset the base enough to avoid blowby.
Only my 2 cents.
