You're flying around the map, shots are clean, then you hit that one player who's basically a moving door. Riot shields in BO7 aren't "overpowered" so much as annoying, and if you keep dumping bullets into the window you're playing their game. The fix is simple: prep for it, stay calm, and pick the kind of fight they hate. If you're also trying to level stuff without the constant grief, some folks even buy BO7 Bot Lobbies runs to get reps in, then bring that confidence back into public matches.
Start with the right kit
Your lethal slot should do the talking. Thermite is the obvious bully: stick it high on the shield and they've got to move, even if they don't want to. Drill Charges work too, especially when a shielder's tucked into a doorway playing statue. Don't bother with "maybe" options like basic frags unless you're cooking them perfectly, because a good shielder will just tank the bounce and keep walking. If you know the lobby's full of turtles, build around it and you'll feel the difference straight away.
Win with angles, not ego
Most people lose because they insist on a fair 1v1 in a narrow lane. Don't do that. If you can swing wide, do it. If there's a head-glitch box, climb it. If there's a stair rail, hop it. Shield users hate vertical pressure because the shield doesn't cover everything when you're above them, and they turn like a bus. If you've got movement tech, use it, but keep it simple: slide past their left shoulder, cut back, and you'll catch their side before they even know which way you went.
When you're stuck face-to-face
Stop mag-dumping the middle. It's pointless and it makes you panic. Instead, chip what's available: toes, ankles, the edge of the arm when they shuffle. You're not trying to delete them in one burst; you're trying to force a mistake. A lot of shield players get bored and pull out a pistol or knife once they think you're out of ideas. That's your cue. Back up a step, pre-aim where their head will pop, and take the free kill.
Make it a team problem
One shield can only face one direction, so call it out and pinch. Even random teammates respond when there's an easy collapse. If you're solo, bait them into moving: tap shots, break line of sight, then hold the next corner instead of chasing. They'll usually stomp forward thinking you ran. And if you want an easier way to practice this stuff without the constant chaos, buy game currency or items in RSVSR and jump into rsvsr CoD BO7 Bot Lobbies sessions so you can drill the counters, then bring those habits back into real matches.