What chokes is best my choke that came in my gun is crap im looking for a good one im thinking about using a full tell me your thoughts on what brand and what size im using a Remmington 870 Express Magnum 12ga with Winchester 5shot turkey loads.

You gotta mess around with a bunch of different choke/load combinations out of your gun.

I'm not sure that I understand why one choke would be better than the other if they both fit in the same barrel and they have the same diameter. What's the difference other than the name?

bowtechbloodbother; You will probably find that .665 is a good size to start at. Are you going to be shooting the Winchester #5 lead loads, or heavier than lead?
centaur 1; There is quite a bit of difference between choke tube brands. For instance I haveIndian Creek, Pure Gold, Carlsons, and Trulock choke tubes all in .660 for a 12gaIthaca Turkeyslayer. Shooting the same load out of these chokes, at the same range, on the same day I end up with wildly different pellet counts....we are talking about a difference of more than 60 pellets from the worst to the best.

I agree with hurricane, .665 constriction is a good starting point. You'll have to experiment and see whether a tighter or more open choke throws better patterns with different shells. Take a look at the Primos Jellyhead, thats a good choke and pretty reasonably priced. You can pick one up for around 45-50 bucks. Another popular inexpensive choke that does well with lead loads is the Undertaker, you can get one of those for about 20 bucks I believe. My Indian Creek choke just came in, I can't wait to pattern it. Good luck!

I'm going to be buying an 870 express turkey gun before spring turkey season opens and it's going to tap me out money wise. Is there anything that can be done to the factory choke to make it pattern better? Does it need to be polished?

Nothinglike that will help much I don't think. Really just need to buy different size loads to see which is going to give you the best pattern. I got a better pattern from federal than my usuall wincherter . I use a Kick's gobbling thunder on a benell super nova.

centaur 1; I have found that a good barrel polish will normally improve patternsquite a bit....just the barrel though, not the choke.
You will probably find that the factory choke will give acceptable patterns to 30 yards or so....so as long as you keep them in that range you will do fine.

Not sure what choke you have now... Doesen't sound like you have a actual turkey choke... I would try a Rem factory super full turkey choke with a load of Win HV #5's... This choke/shell combo throws a killing pattern out of all 3 of my Remington turkey gunsThere are better choke/shell combo's but it sound like your a rookie... So I would say apply the KISS system

Ive found that my factory full is best for my gun. I bought one super full choke and it was like shooting a slug out to 20 yards. That season I had birds that came in to like 15 yards and I missed because I had no pattern that close. Just be mindful of this, because a really tight pattern doesnt allow for any mistakes.[&:]