Not sure if this is bug or feature but when enemies are close, it seems that semi auto weapons have slower, sluggish or irregular attack rate. This applies to shotguns, pistols and melee weapons. When shooting while enemies are not present those weapons have consistent attack rate but when enemies are close it seems that there are small delays and the shots aren't released at the usual rate. I know that when taking hits the char may suffer pain and be immobile for a moment but these attack rate changes also happen when the enemy is just close, attacking my companion for example.
Best way to test this is with powerfist. When hitting thin air, it has pretty damn fast hit rate. But if you hit enemy, it's very inconsistent and there are times when you can't release a strike instantly even if you totally should be able to.
Could it have something to do with max dps?