So I just picked up a Remington 870 Express Synthetic. The Remington site says it has a fixed choke. Being new to all this i'm trying to understand all this. I understand chokes as different chokes allow the bird or buck shot to stay in a tighter pattern or group or spread out more depending on the choke.
My question is I want to shoot bird/buckshot and slugs at the range. Somebody I know mentioned to be careful with slugs cause if they don't fit you can mess up your gun.
I currently have these slugs.
Upon checking my barrel I see this below on the side. Would this mean the fixed barrel choke is a cylinder sized choke? And if so, can slugs be fired safely from them?
I'd rather be safe than sorry which is why i'm asking.
Gun in question: