I have a remington 870 that i use to turkey shoot with, the targets are 25 yards away. do you all know any tricks that i can do to make this gun shoot better or a certain choke that i should be using?
Any card or Turkey shoot I have ever been to, you were not allowed to use your own shot shells. They have always been provided. As bmassey mentioned below, the shells are an inexpensive low brass of #6 - #8 shot.
Lengthening the barrel forcing cone, backboring, and an assortment of screw in Full / Turkey chokes would probably be the best way to go if you want to consistently be in the top 20% of competitors. Then its a matter of luck.
I got into going to turkey shoots about three years ago and went through a bunch of combinations of guns and chokes.
My first was an older Mossberg 500 I have because it's got the factory poly-type choke which I naturally cranked all the way tight,then started backing off, looking for the "spot".
It didn't fair too well, won a few, but percentage wise, was prolly no more than luck.
After experimenting a good bit, I finally settled on my early '70s vintage 870 Wingmaster with a newer 28" VR barrel I bought for it a couple years ago. After trying a few different chokes I borrowed and a couple I bought, I found a winning combo with a Carlson super full, ported turkey choke and for sighting purposes, replaced the end bead with a different one and added a center bead.
I've won a good percentage of the shoots I've gotten into since settling on this combo and if nothing else, have the confidence that this combo will give me at least as good a chance as anyone out there...
I use Rhino Choke Tubes, make sure your barrell is x-tremely clean,as close to a mirror as you can get it. Polishing it w/ a bore hone works great, but is not necessary. Its hard to drop that much change on one. A super clean barrell might sound funny, but trust me, try it and you shall believe.