Hello,

I recently had an 870 express 20ga sort of fall into my lap, one of those deals that  you just can't say no too. Unfortunetly, for me it just ins't evil enough. Does anyone know if the standard 870 furniture will fit on the 20ga model? Will the 12ga mag extensions work or does someone make a 20ga extension?

Thanks in advance

Some wood interchanges on Remington 12 and 20 gauge guns, and some doesn't.
I'd suggest saving myself some money and grief, and simply ask Remington.
They have an excellent customer question system in their customer service website:
remington.custhelp.com/cgi-bin/remington.cfg/php/enduser/std_alp.php

As for magazine extensions, 12 gauge models will NOT fit, but happily, Choate makes 20 gauge models:
www.riflestock.com/catalog_page.cfm?queries_index=index10&ProductCode=27&ProductSubCodeID=177&NewProduct=0
Note that Choate calls these the "lightweight Model".

For best results, email Choate to get the exact model you need.

See if a Knoxx Spec Ops stock will fit it.