How long of a mag extension for 870 express?

[TCW]

For a 20" barrel, which mag extension (Choate) should I get...3 or 4? I don't want it sticking out too far beyond the barrel...
Thanks!
TCW

[Dave McC]

3....

[Hoosier_Buddy]

Dave McC,

Why 3 and not 4?

[Dave McC]

A 3 shot extension comes in at about the length of a 20" bbl. Mine is actually about 1/8" longer.

In truth, a 2 shot extension has better dynamics and handling, IMO.

[TCW]

Thanks, Dave.
That's the one I ordered. I remembered that my former SG (Mossy 500 20") had a 7 round tube, but then I thought of the 590 20" which has a 8 round tube...both looked flush w/ the barrel. Weird.