I want to get a fully rifled slug barrel for my 12 ga. 870 WM ,with cantilever mount ,should I go with the 20 inch rem. barrel or 24 inch Hastings barrel?I seen that Rem. makes a 23 inch barrel but only in a matte finsh my gun is highly blued,is there much diffrence between a 20" & 23 or 24" barrel in accuracy?Also Ive been hunting deer with my LT1100 20ga. with smooth bore 21" deer barrel but want to mount a scope which I cant with this set up,Im confident with this gun to about 65 yards but want to use my 12ga.for greater distance that I have sittng in the cabinet collectting dust with the simmons 4x shotgun(diamond rectical) scope I have sitting with it.