870 and 660 too tight?

[Ihuntoldschool]

This is interesting. I wonder why the 665 beat both of the 660s since the 660 is definitely not to tight?

Now could it be that every barrel is different and while some prefer 660, others may prefer 665?  Hmmm.

[55esox]

I have a 2005 supermag with a .660 Rhino and it shoots right at the published numbers that Nitro says.  I would start with a barrel polishing, as that will do nothing but help you out.

[Longshanks]

This is interesting. I wonder why the 665 beat both of the 660s since the 660 is definitely not to tight?

Now could it be that every barrel is different and while some prefer 660, others may prefer 665?  Hmmm.

   I think that is a factor from barrel to barrel but I think it also has allot to do with what kind of choke it is. The internal aspects of the choke make a big difference. Kicks and Ventilator .655 shoot the best patterns out of my 870's, but when it comes to Indian Creek .665 provides the best results. There is also the variable that comes with barrels being in much different condition than one another. Allot of these barrels that are turning awesome patterns have been polished and are kept in amazing condition through deep cleaning and cleaning after each shot. It takes a process to get the gun to shoot that way in allot of cases. I have a rem 870sm that wouldn't pattern well with JH .665 or any other choke for that matter. Agressive polishing by my gunsmith turned it into a great shooting gun with Ventilator .655.

[Gooserbat]

Always heard the JH .660s shot the Hevi shot straight 6s and 7s well. What kind of shape is the barrel in? Maybe a deep clean would help.

My exact thoughts.  A clean barrel has got me 30-40 pellets, also do not disregard temperature ad it will have an efect on your pattern.