1. Dirt, crud, dried grease or debris interfering with parts moving. Some lubrication (fine grease) needed on carrier-follower cam and spring tip.

2. Broken magazine-gate/carrier-follower spring. (Rare)

3. Follower-carrier assembly bent, damaged, or small pin, that holds follower in carrier, is out of position and causing drag.

4. Wrong carrier-follower assembly. (Assemblies changed over evolution of U.S. Krag models).

Other related issues: (Something wrong with magazine cut-off function, side-plate, or receiver feed-path surfaces).

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