Sounds like that could be the problem. I've target shot with broadheads through the mesh windows of my doghouse and been right on. Never tried field points. It is unusual shooting out of a blind for the first time so it could also be you're doing a little something different. The doghouse is a small blind in my opinion. It does the job, but doesn't give you much room to shoot so you have to practice at it. I just bought a larger hub style blind and feel less "hunkered down" then I did in the doghouse. Felt like I was hunting out of a bunker with the little portholes.