i have a remington 870 express magum in 20ga with a non rifled slug barrel and was wondering what slugs to use to get the best out of this gun and should i put a scope on it if so would u drill and tap or use a saddle mount?
go buy 3 or 4 different brands of slugs and go to the range. See which patterns the best. What works in one might not be what works in yours. Scope is personal pref. I would put one on but my eyes aren't what they use to be.
Go by the rifled barrel....with the cantelever scope mount on it...that is your best bet. I have the 870 xpress in the 12 ga. 3" and It loves winchester partition gold slugs. I can group them less than a 1/2 inch apart. Have even put a few through the same hole.
seriously, the rifled barrel is the way to go, but in all honesty, i spent 4 years hunting deer with a winchester 1300 using the brass bead and the mod choke throwing $3/box remington punkin balls. get a box and hit the range. see how your gun likes em. you might be surprised. if not the remmy green box, try the brenneke KO slugs. they are pretty wicked too, and about $5 a box.
My hubby has tried ever known slug made in a smooth bore barrel for hunting in Ohio...after the smoke cleared, the shoulders healed, the pain subsided the clear winner is......FEDERAL 2 3/4 in TRUE-BALL...1 oz slug.. it has a badmitton type wad system that stays on the slug out to about 75 yards..accuracy at 50 yards is around 1 1 1/2 inch..more than enough to drop a whitetail..and they do drop them in their tracks..all those fancy sabots and every other bullet type didn't compare to these..they are not easy to find in PA..you may do some searching..
A Tioga Co. cousin thumped a pile of deer in Steuben Co. NY over the years, with his Win. M120 Ranger 12ga and 24" smooth bore slug barrel w/sights. All he ever used, were the cheap Rem. 2-3/4" 1oz slugs.
Most deer were killed at less than 50 yards, as if often the case when hunting in the woods.
Now that rifles are allowed in that county, he uses his 30-06 to hunt there, but that slug gun always brought home some venison, years ago.
in my experience hunting in ny(before rifles) and ohio, regular foster type slugs(non sabot)are only accurate to 50 yards. after that they are unpredictable. this experience was with a winchester model 120 smoothbore12 ga with a scope.i bought a rifled choke tube and some 2 3/4" breneke ko sabot shells. my groups at 75 yards were in the 4" range. definatly better than the foster type slugs.took probably half dozen deer with that setup. going to use it in ohio this year
I was able to hit a 4" target consistently at 100 yds with my Ithaca Mod 37 with 28" modified barrel with the Winchester foster slugs, but Remingtons and others didn't fare as well. Like the others have said - get a couple boxes of each and see if any will shoot consistently with the smooth bore.