RE: Will 4 inches on a barrel make much difference?
You know, this question brings up a point I have struggled with. I truely in my heart belive that a gun should fit the shooter first and foremost, but am torn with wanting every performance advantage I can get. I know that 200FPS in not really an issue for 99% of my practical shooting, but I sure hate knowing it is not available.
In my opinion a tactical rifle should be even more ergonomic for the shooter. We all think about the spectacular 400 yard shot that saves a life, but have you failed in your mission if you have to take a 400 yard shot? Would you want to have to shoot a guy from 400 yards that was holding your kid? Well what if the shorted gun would help you to crawl undetected to 200 yards then take shot? 400 yards at 2900 FPS or 200 yards at 2700FPS?
If the shorter gun really feels better at 20 buy it, 200 FPS means little if you miss.
But yes the 20 will probably on average be a little slower, with slightly less power/energy.