MidwayUSA has has Wilson magazine spring & follower kits on sale this month for $3.99 each. I bought 5 kits to replace the factory springs & followers in the 5 Colt-made magazines that I regularly use in my LW Commander. The Wilson rounded polymer followers are much friendlier to alloy feed ramps than the factory steel followers.
Installation is straightforward, remove the old, put in the new. A 5 minute job. While the spring is out, this is also a good time to clean the inside of the magazine tube, & finish with a light film of Birchwood Casey Sheath.
Wilson magazine spring & follower kits