I do not think there is one perfect form for everyone. Trying to change you way you shoot, so that you have what some one else says is good formwill cause you more problems. The supposed perfect form should only be a guide line when you are starting out. But once you are comfortable shooting and can do it the same every time, that is what is key. There are so many so called experts out there that tell you to line up your arms and below so as to use as little muscle as possible and have your bones be the brace and yet others that disagree. So who it right on what perfect form is. I feel only you can decide what feels right for you and that you can repeat the same each time