Ya, own a 430 in 20 ga.
So from what I gather if I had a 12 ga the 20 ga barrels are going to have even a bigger gap than the 16 that you own.
It's kind of a win/lose situation. They will fit but they have a gap on the inside of the frame.
I'll measure up the 20 ga in a bit, just having my morning cup of joe.
That’s pretty much how I see it. The barrels seem to mate with the breech (though there may be internal differences I haven’t accounted for) but we’re still left with a gap between the inside width of the frame and outside width of the barrels. I guess an enterprising person could make an adaptor to fill in the gap if Savage used the same external dimensions for the 12,16 and 20-gauge frames and you stuck with the 12-gauge forearm. I will have a 20-gauge 420 by the end of the month to compare with my 16 and I can post the results.
PS - I’m sure that you, like me, have found it difficult researching these guns but I did come across one account that stated the 12 and 16 gauge guns were built on the larger frame. So it remains to be seen if that is true and if the 20-gauge represents a smaller package.
