I have used this for some years and most of the time it's great. You hav eammunition close for reloading insteda of having them in pockets. I use it for all my rifles and on my shotgun pump that I have for going after wounded animals.
The only problem I had is that I have lost 1 or 2 shots from it, I have never though felt that it's been in the way when shooting. A hint is to make a hole in the bottom to have the strap holder through, it will then sitt very firm on the gun with no chance to twist around.