Don’t be afraid to use special weapons
When you come across the infrequent Dropshot or Torque Bow, temptation may cause you to hang on to that weapon without ever actually using it. However, in Gears of War 4, you shouldn’t be afraid to use those special weapons whenever the opportunity presents itself.
Enemies can soak up a lot of bullets, especially on higher difficulties. Using rare weaponry like the Tri-Shot, Salvo Rocket Launcher, Boomshot, or Buzzkill can make short work of certain enemy types, and can really help you out of a nasty situation.
Since you’ve likely played through the campaign on a lower difficulty before replaying it on Insane, you’ll know where some tougher enemies or small bosses may spawn. Use this knowledge to spare your ammo a bit ahead of time, but don’t necessarily cling onto a weapon specifically for a boss fight. There’s plenty of ammo pick-ups along the way, so use whatever weapon you have at your disposal whenever you feel the need to do so.
Do take note that you shouldn’t waste ammo, however. Blindfiring a Mulcher may make you look like a total badass, but don’t hesitate to pop into cover to score some steady, precise hits. You’re better off using ammunition thoughtfully rather than wasting it all on potential hits, or clinging to it for when the ideal situation arises.