get cheap 870 express , chop barrel and add tube extension . will have to feed 2 3/4 but will suffice .

 

870 express will handle 3" just fine unless marked otherwise......quite a few listed here just have to search for them

 

http://summitgunbroker.com/870p.html

20" 870 police with rifle sights was just on sale for $285 yesterday...

 

I ordered 2 and then had to have my money refunded. Got it back today. They ain't 870P's , they are standard expresses.

 

I believe these are a better deal: http://summitgunbroker.com/wingmaster-18-.html

The action in on those old wingmasters is soooo nice. Metal trigger guard and chromed bolt too...