Re: Shooting Jacket
I have two Creedmoor jackets. One is made from Cordura fabric snd the other is their stock canvas jacket. The best is the Cordura jacket. It is much more durable and a bit heavier than the canvas.
I loosely snap the top two straps when shooting seated and leave the rest open. It's comfy that way and helps to cut down the pulse you might see in your scope without a jacket. It also pads the contact points of your elbows to make the position more stable.
When shooting offhand I pull all of the straps tight. It seems to help a bit. Another suggestion is to order the air vents in the side. Those do allow in some breeze and help keep you a little more comfy and dry inside.
Best of luck!