I am looking at starting to shoot some 3 gun matches. I already have a Remington 870 along with an 18.5" and 28" barrel. What do y'all think will be best to set up? I am thinking the 18.5 for maneuverability.

I'm thinking of shooting in the tactical division.

Maybe just me but something in the middle? 22" 24"?

I had the Mossberg 500 and I believe it had an 18 inch barrel. I couldn't knock down the steel with 7 1/2oz shot at 25 yds. But I had no choke so YMMV.

Upgraded to the 930 24 inch 9+1. But that again is just my thought.

I don't want to buy another barrel yet, but agree with you 22-24 would be ideal. Just want to get in and maybe upgrade to semi later on for a dedicated 3gun shotgun. I'm stuck with choosing between 18.5 and 28. I guess the good news is the barrels are super quick to change out.

Any barrel that has chokes! Shotgun shells are pretty much done after 18" (so I have heard) so anything after that doesn't gain much velocity so barrel length on shotgun is all about swing, but swing is used in trap shooting. Go feel out some lengths and see what you like, I have see 18.5 to 28" with 21, 22, 24, and 26 being common. Mag tubes can extend 10" past the barrel (so I have heard) so dont let that influence your choice unless you are going for a certain look.

what type of courses does your local club shoot?   inside vehicles a short barrel is a lot easier to handle...I'd stick a light modified choke in the 18 1/2 and an 8 round tube and have fun...check out a couple of videos of Cowboy Action Shooters and work on your single load technique in case you have to shoot from a stationary position..

My guess is that the 18.5 does not have chokes, for that reason use the 28" with an IC choke.

Thanks for the help so far. Both barrels have chokes. Currently the 18.5 has a modified choke and the 20 has a full choke.

You will want removable chokes, if both barrels are not removable then go with the modified since it can shoot slugs

Thank you all sooo much for helping a noob out here. You are so kind to offer your knowledge!!

I do need a little more help with this SG though ...

Both barrels have removable rem chokes.

After doing more research I have found that I was measuring the short barrel incorrectly. On the net, the way to measure the barrel is to 1) Make sure SG is safe x 2 2) put a dowel down the barrel with action closed and make a line 3) measure the dowel to the line.

After doing this, I have found I have a 20" barrel with removable rem chokes ... see pics.

Now I have two additional questions:

1) Mag extension ... Based on my online research choices are Nordic Components (I really like the clamp relief groove on this one, although it's more $$$), Shoate, TacStar

I am leaning towards the nordic components +3. Assuming that will give me default of 4 + 3 + 1 in chamber = 8. Is this correct and is this enough to start with? Brownells Linky

2) Fibre optic sights ... My 28" barrel has truglow fiber optic sights mounted to the barrel rib vent. I have shot this regularly in sporting clays and trap and love that sight. I want to add trueglow fiber optic sights to the 20" barrel, but it has rifle sight setup (I think). I cannot find what size sights I need to accomplish this. See pics of my barrel and the current sight configuration ... Will the Rem. Rifle set work? Item 902-00-005WB on Brownells Linky

Thanks again for ya'lls help with this!!!!!!!!!

Here are the pics of my barrel:

http://i1236.photobucket.com/albums/ff453/andrewbrockman/Mobile%20Uploads/C45C2292-8729-4A0D-8D23-7357883A77CC.jpg

http://i1236.photobucket.com/albums/ff453/andrewbrockman/Mobile%20Uploads/50988465-9AA7-41BF-AA71-010BBB47C2EB.jpg

http://i1236.photobucket.com/albums/ff453/andrewbrockman/Mobile%20Uploads/70C0F540-2FF3-4739-82E4-C7AE73A4F8D8.jpg

http://i1236.photobucket.com/albums/ff453/andrewbrockman/Mobile%20Uploads/91739C8C-BFDB-419B-93E6-E0F173C2FA83.jpg

http://i1236.photobucket.com/albums/ff453/andrewbrockman/Mobile%20Uploads/3ED30077-967B-45E0-9716-6DFAEB939970.jpg

http://i1236.photobucket.com/albums/ff453/andrewbrockman/Mobile%20Uploads/E959E55A-6F19-4382-9389-6A07A8804E2F.jpg

http://i1236.photobucket.com/albums/ff453/andrewbrockman/Mobile%20Uploads/8B26FBB9-05BD-4745-967A-F698B0137F0F.jpg

http://i1236.photobucket.com/albums/ff453/andrewbrockman/Mobile%20Uploads/6A28AF4F-CFE4-4A6D-9F34-58272CA016FF.jpg

Use the 28", the advantages outweigh the negatives especially if you can shoot trap great with it. You are already used to the swing and that helps when shooting targets. Many people like the hi viz sight, I have used ghost rings which is similar to those rifle sights and you can't see anything. Use it until you cant stand the length and then buy a new shorter barrel, that is if you end up not liking the length. Save your money for other things.

Mag extension,  nordic is the cats meow, carlson also has extensions too.

You will want a 8 round tube minimum for 8+1 or

9 rd tube so you can still have 9 in the gun when cruiser ready although this is a rare starting setup or

12 rd tube so you can throw a quad load in at the buzzer

Thanks for all the help! I'm going for a Choate +5 which will give me 9 total  and I'm going to use the 28" barrell. I guess I had better start keeping an eye out for a good deal on a versamax