I wanted to ask if anyone was familiar with swapping out the barrels on my 590A1 and my old Ohio National Guard 870 wingmaster.

I'm getting a shotty suppressor and would like to be able to shoot these suppressed so I need choke threading. Instead permanently modifying them I figured I could just pick up a barrel that's already threaded. I'm just not sure which barrels are compatible with the 590A1 (all 500 barrels?) And what or if any barrels can I swap in for the 870 wingmaster.

Any help would be greatly appreciated!

It's been a while but the 590 barrels attach differently so you can't use 500 barrels. The 590 actually is similar to the Remingtion in the tube and cap it uses. I have no idea if there were different mag tube lengths but that's all that really matters. The 870 Barrel is going to be easier as they made a million of them. Honestly I'd probably just thread both of them but maybe the ONG gun is collectible but if the 590a1 is just a generic model thread it.

A 500 barrel will not fit a 590. You will have to get another 590 barrel.
Why are you opposed to having your current barrels threaded?
I had the barrel on my 590A1 threaded by Rose action sports and love it.
Being able to swap chokes depending on what I am shooting makes it more versatile. I have cyl bore, imp cyl, full, and a extended rifled choke for slugs.