Range of motion of follower/carrier-arm and spring strength and action are easily checked.
The curved flat spring puts tension on the magazine-gate, as well as, powers the carrier-arm by bearing on its cam. The magazine-gate works firmly. The carrier-arm requires only moderate spring tension, but, should move and compress smoothly.
Compare your assembly with posted photos. Follower and tip of carrier should be shaped and project as the ones in photo. The tip of the carrier plays a significant role in lifting and feeding the last cartridge in the magazine. (The 'earlier' cartridges ride on the cartridge behind them).
Photo shows an original .30 U.S. Army 'last round' in magazine.
Attachment 94538