If you want to practice dodging with boxes, then what's the point of having a practice room? I Mean it's called practice for a reason. Get a decent sparrer to shoot at you and,in my opinion, you will get better faster. Because remember there is freeze on guns. So if you shoot at the wrong time you can get hit. NPCs can be a good idea like star said, but they probably wouldn't spar like an actual player. Ok for ex. let's say you get good at dodging those npc bullets. You say you're ready for spar and when you go to spar it doesn't feel the same. Players are different than npcs. And I find it difficult to replicate a pro sparrer's reflexes, or timing, etc. Then again people have different sparring techniques(I think). What if you run into a bar spammer? I don't think there would be an option to choose any gun you want with the npcs. So in my opinon the better way to get better in spar is to spar an actual person.