9 mm to .410
 

Does anyone have experience with the adapter to fire 9mm in a .410?
Is there a downside to trying this?

I'm not aware of such an adapter and I wonder about how it incorporates an extractor for the rimless 9 x 19 cartridge. Or do you push out the fired casing with a dowel or such?

People also ask
Can you shoot a 9mm out of a 410 shotgun?
This adapter allows you to shoot 9mm Luger out of your 410 Break Action Shotgun! Smooth Bore 2.5" Adapter. For 3" Chambers. It's like having another gun for pennies.

Above is a copy from google.
There are also YouTube videos.
I have my suspicions - that's why I though I should ask

With 9mm being .354”, I don’t see how it would be very accurate out of a smooth bore .410 bbl.