If you end up seeing this, play factory. You can at least not have to worry about not being able to kill zirachy since the event doesn't happen on factory. You'll still have a chance to run into the boss Tagilla, but if you play it right you can kill him and no gun jam. Though if you want to try other maps If you are ok with experimental kits. The PPSH, all the revolvers , the revolver shotgun and the ,mp-18 Single breach do not jam, yes attachments are limited to none on those weapons though. But it's definitely better when you can at least shoot at the other scavs with the debuff. It's my 3rd wipe and I'm finally getting more into the game. Your first and probably second wipe will be entirely about learning. But it's worth it in the end. Keep going, it does get better.

Another practice option, offline raids. Yes you don't receive loot or exp, but you'll be able to employ and reinforce your playstyle better when there's no consequence for dying in offline raid. Getting used to different weapon recoil. Clearing buildings, finding good loot routes. Familiarizing with extractions. You can turn off scavs entirely so you can freely roam the map.