Depending on how hard you push youself while swimming , i would do my swim before lifting,
reason for this is that when your lifting your warmed up and oxygen is allready pumping through your muscles
as swimming is a incredible full body exersize and will ready you body for the pain your about to put it through
the idea is to push your muscles to failure after warming them up, not raping them after making them fail.
Swimming after lifting weights is definitly a bad idea if your trying to build muscle, esspecially if you swim hard.
and always stretch your ahoulders out well before swimming if your gna start your workout for swimming.
You also have to make sure you consume enough calories to make up for what your burning off while swimming , whether
it be before or after .