I am pondering a barrel project for an old Stevens 414. Does anyone have specs for the barrel threads on a Stevens 44/414?

I pulled measurements from my old 414 and found .800"x20 tpi.

When I looked online, I could not find any drawings, but I found different specs in forum posts. One spec is close to mine, but the other would allow me to use an off-the-shelf die.

I found .805"x20 tpi on one forum post from Greybeard Outdoors. This measurement is similar to mine, so could be the same allowing for wear.

And I found .8125"x20 tpi on another forum. 
This measurement would use a 13/16"x20 (NEF) die.

Can anyone confirm any of these 3 thread pitches?

If anyone has a dimensions of the barrel shank and thread area that would be helpful also.