I use the .660 in all 3 of my 870 2 with H-13 6's and 1 with the 7's and all throw awesome dense tight patterns. the barrel length's are 21",23",26". I use the truglo pro sight's on 1 of them and they work very well. The only reason I went with the trugol instead of the Williams was that's all the gun shop had at the time. You will definitely wanna shoot it to see if its still on poa, poi if you remove the sights.