The Savage 220 is back from
Indian Creek Shooting Systems (Click Here) choke tubes and
Briley Manufacturing (Click Here) gunsmiths!
The turkey choke tube specialists at Indian Creek Shooting Systems outfitted the Savage 220 project gun with their 20GA Invector Plus Black Diamond Strike and Platinum Pro Elite choke tubes.
The fine gunsmiths at Briley threaded the business end of my custom smoothbore bull barrel for
20GA Invector Plus choke tubes (Browning and Winchester's 20 gauge screw-in choke system). Truth-be-told, I was unable to identify
ANY other gunsmith or company in North America that is equipped to thread specifically for Invector Plus 20 gauge choke tubes (if you go this route for
Invector Plus 20GA screw-ins, you might as well save time and send it to Briley from the start).

Indian Creek reamed the barrel with a
Dave Manson Precision Reamers (Click Here) backbore reamer and 34" drive extension (thank you SPURGETTER!). The bore was reamed from the original gundrill .594" size to .625" in order to remove any surface-hardened spots from the heat of the gundrilling process or variation in the hardness of the 4140 PH steel itself.
Briley Manufacturing also honed the .625" reamed barrel bore on a 2-stone honing machine. The honing process removes any "high spots" and/or "low spots" that exist along the barrel's bore. The process allows for near perfect bore concentricity and a consistent bore diameter for the entire length of the bore. The benefit to the shotgun (and the shooter) is that patterns thrown by the shotgun become very consistent, tight, and predictable (as predictable as a scattergun can be anyway).
Here is my .6
XX" finished barrel bore ready for competitive shooting (it is a mirror inside there!):

In order to get this shotgun project off the ground, I experimented with a variety of Indian Creek Shooting Systems' choke tubes with exit diameters from .540" through .575" and the 3" Hevi-13 1 1/4 oz number 6s shotshell. For my NWTF still target competition endeavors, the .560" Indian Creek Platinum Pro Elite (non-ported and no wad catchers) won out for best pattern "cores" and shot-to-shot consistency.
Here is the .560" Indian Creek choke screwed into my custom barrel:

Another look from a different vantage point:

Up next: Mounting 1" Burris Signature Zee scope rings (Weaver-style) and an optic (undecided at this point).