I use an 870 Wingmaster with a Hastings 24″ rifled barrel with cantilever scope mount. I have a Simmons 4x on the barrel.
I’m zero’ed in @ 100 yards too.
This gun will give me a 3″ grouping @ 100 yards. I would have no hesitation taking a 200 yard shot with this gun, if the conditions allowed me to make the shot.
In other words, the gun shoots perfect. The only reason I would hesitate for a long range shot is the conditions I would be under to take the shot. If I had the proper rest and comfort to take a long range shot, I would be all over it.
Thus far, the longest shot I have made with the gun to bring down a deer is 140 yards.
I shot Federal Barnes Expander, 2 3/4 inch, 3/4 oz sabot.
I’ve tried the 3 inch to see if it would give me better distance, but I’ve only found my groupings to open and I found no gain in distance.
My nephew has a Browning A-bolt slug gun. This gun actually shoots tigher groups than my 870. It is amazing accurate and smooth to shoot. It is the best slug gun I’ve ever had in my hands……..