870 18.5" or 21" barrel

[3seasons]

Ok guys im going to build a 20ga for me\my daughter and wanted to know opinions of what to get 18.5 or 21" barrel  Pros and cons of each.  Any pics of guns\patters would be great.  Ive done some searches but would like some input from you guys that have built one.
Thanks I cant wait to get started.

[gophert]

I personally would go with the 21" barrel.  You're not going to probably see a big difference, but the rule of thumb is that the longer the barrel the better the pattern will be.  Now, keep in mind, that if this is for your daughter, her shooting range will more than likely be 25-30 yards at the most, so really at that range it won't make a difference.  I have built 2 870's and both were 21" youth models.  They will both bust a bird at distances farther than I can say.  Keep in mind too that you will probably need something with an adjustable length stock if you both are going to use it.  This is a picture of my daughters gun.  The shooting stick has really helped her. She killed her first bird with it at age 10.

[remmy1187]

                          These are mine, both 21 inch barrels.   The adjustable stock on the right is an ATI for the kids and mine on the left has a mesa tactical stock.

[3seasons]

Thanks for the info.  Russ and you guys have helped me out a lot.
I'll have a 21" youth 870 here Monday. Been talking to ATI and I'm looking hard at their stock. Gonna check out a couple others also, want the lightest possible one I can get that has good recoil reduction too.

Now I have to figure out what choke to go with for me. 

Remmy is that a dip or did you paint the gun on the right? Looks like tree bark.