John, Panzer Arms does not make the BP12 in a 20ga version, however other manufacturers produce 20ga bullpups. Just google '20 gauge bullpup' to find them. Here are 2 that are in stock at Bud's. budsgunshop.com/product_info.php/products_id/128770/american+tactical+imports+american+tactical+importsg20bdb+bulldog+20+ga+3+16+5+1+black+black+fixed+bullpup+stock ........and budsgunshop.com/product_info.php/products_id/713093231/lkci+eternal+bp-20+bullpup

Hi John, a couple of options in 20 Gauge are here : budsgunshop.com/product_info.php/products_id/128770/american+tactical+imports+american+tactical+importsg20bdb+bulldog+20+ga+3+16+5+1+black+black+fixed+bullpup+stock -------------------------------- budsgunshop.com/product_info.php/products_id/723017866/bull-dog+20+18.5+tan ------------------------------ Spare 20ga Magazines are available here : https://gunstuff.tv/product/rock-island-4236382-vr-series-20-gauge-rock-island-vr82-10rd-magazine-blued-detachable/

John, no but here's a link to the closest one I could find in 20 gauge. It's the American tactical bulldog 20 gauge...................... budsgunshop.com/product_info.php/products_id/128770/american+tactical+imports+american+tactical+importsg20bdb+bulldog+20+ga+3+16+5+1+black+black+fixed+bullpup+stock ......................... And here's another link to the same shotgun but it's black and tan color and it's slightly cheaper ..................... budsgunshop.com/product_info.php/products_id/723017866/bull-dog+20+18.5+tan ..................... That's the closest bullpup shotgun in 20 gauge I could find compared to the bp12. Hope this helps.

This is what I was able to find for you in a BP 20G.
Does anyone make a 20-gauge bullpup shotgun?
American Tactical Imports Proud to Bring in a New Bullpup Shotgun from PARS MFG from Turkey now in 20 Gauge. This Sleek shot gun is brought for the people at American Tactical Imports and Par MFG. this semi automatic shotgun is built in a Bullpup configuration lending for a small handy layout.