I've been using an 870 wingmaster for the past 25 years so it is my only point of reference. Bought a Nova on Friday and tried it out this weekend. Shot a few light dove loads and I noticed that when firing the bolt throws back about a 1/4 inch and the chamber is slightly open. I never noticed this on my 870. What will happen when I shoot a high velocity magnum 3 1/2" shell? Is this normal and is there anything I need to be concerned about?