It depends on ammo but
for a standard .45 ACP (Im assuming)
stock Colt Government is 17 pounds.
An upgrade to 18.5 may help.
A Commander uses a heavier spring because the slide has less mass.
My Commander uses a 22 or 24 pound spring depending on the load.
Stock is 20# I believe.
Go to a range where you can watch your brass
eject. With a standard velocity load, brass should be shucked pretty close together somewhere from 3-6 feet away from you, IMHO.
Test your gun after installing any new spring.
Try WCWolff (not sure of website) stay away from variable power springs unless you have a compensator attached to your barrel.
Sounds like your spring is weak.
A semi-extended ejector may also alleviate the problem.