It seems like as far as mag extensions go, the Nordic Comp and the S&J extensions are the way to go. Major pros and cons as I see them are:
Nordic - made of aluminum - nice and light, but may want to clamp it to the barrel to protect it.
S&J - made of steel - tougher, but heavier.
For followers, it seems that GGG&G, Nordic, and S&J are crowd favorites. Should I be concerned with things like galling if using the GGG&G follower (stainless steel) in the Nordic tube (aluminum)?
How many rounds do you want to add?
What are you doing with the shotgun?
My preference is to the Nordic Tube for a few reasons:
cap comes off at end (cleaning, ease of installation)
more options to capacity than the S&J
I don’t think galling would be an huge issue, but it depends on how well machined the follower/extension is. you’d probably see more removal of anodizing or powder coating first if its very good, otherwise a burr on the follower would do some damage. I have not seen anything on this however.
Allen
Nordic by far. No other product can take the beating that Nordic products can. We 3gun shooters are NOT nice to our shotguns, at all. They get thrown into dump barrels, slammed around barricades and just not treated friendly. Nordic tubes take a beating and work.
I’ve got a +8 on mine for a total of 12 in the tube and a 24in barrel.
I want to add 2 rounds capacity. It will be used for HD, and if I can find a barrel for it, it will likely serve double duty for trap and skeet. Because of this, something that wouldn’t need a barrel clamp would be great.