Which length rifled barrel for my Remington 870?

[Tree Farmer]

I live in a firearms restriction unit. I bought a new Remington 870 in 20 gauge. I am now going to order a fully rifled cantilever barrel. I can order the Remington barrel in 18.5, 20 or 21 inches. Do you think the extra 1.5 or 2.5 inches will make a difference over the 18.5 inch barrel?  I will be shooting the Hornady SST slugs. Thanks in advance.

[Bob33]

I would go with the 20 or ⁸21. The extra length wont do much to increase velocity but will reduce the effect of muzzle blast and flip a bit.

[Brushcrawler]

Whatever you choose, you may want to try a few different slugs. My 12 ga definitely likes Remington accutips better than several other options. It’s not an 870, but like rifles they can be picky.

[Davidicus]

I don't think it matters, especially since you'll be using a scope so sight radius won't be an issue. I prefer shorter barrels myself. I have an 870 Super Mag Turkey model with a 23" barrel that I've used for everything from duck to jackrabbit.

Be sure and post a picture of your gun when you install it.   

[JakeLand]

My rifled slug barrel ( open sight ) is a 20” and it’s very accurate