When deciding how to handle ammo counting and reloads, first consider the genre of the setting. If its a post-apocalyptic survival, modern zombie horror, or tactical military squad combat, then that implies that every shot is a scarce resource and you should track ammo. From the number of rounds in a clip to the magazines taking up limited inventory slots. Reloading should take a full turn (unless otherwise stated by LOOT or TAGS) to force a tough decision about whether to run for cover or charge into melee. Use physical props like glass beads or Nerf darts to keep their number of shots firmly in sight.
For high adventure, pulp action, or cinema inspired gun-fu then don’t count ammo and consider the characters always have weapons and ammo nearby and ready. The Altered State rule of making the gun useless on a roll Attempt of 1 works well to push the players to switch up their weapons and combat style.
My default for a mix between realism and fun is not to keep count of ammunition for small arms. For heavy weapons, I think you should limit ammunition. Man-portable rail guns, shoulder-worn rockets launchers, and tripod-mounted machine guns are heavy weapons that should do multiple dice of Magical/Ultimate Effort. You can justify counting their shots because of their higher lethality and sheer bulk.