I finally got to finish (for now) and test some of the mods I have made to the SA-20. Thanks to Bobster for advice on the bolt release button.
The first thing I added was the choke. On the 20 inch cylinder bore it made a big difference, especially shooting trap. The
Trulock chokes (extended IC and IM) also seem to make it handle steel targets better including the dreaded Texas stars. I did not try the choke thread myself.
Mike Orlen did the work and a perfect job too. Apparently the chrome lined barrel made it impossible for most of the people I called.
The rest of the work I did myself...mostly.
The mag extension is from
Choate. Filing out the crimp in the mag tube went pretty smooth. Just be careful to tape the end of the file, keep the end of the tube square with the axis of the tube and don't remove too much metal.
The bolt release extension makes a tremendous difference. It is actually made for a Benelli by
Taran Tactical. They even provide the hardware and some much needed advise. It makes releasing the bolt a light tap instead of having to squeeze that small button. This was kind of tricky as there is not much metal on the button to thread. They provide a 5-40 flat head screw but I changed it out for a 6-40 (not 6-32) to get a little more thread in the metal. I am not sure how well the tapping will hold up after some time. I do have a backup plan that involves a little welding before threading.
Lastly I opened up the loading port a little. I say a little because I have seen some guns completely hogged out to where the follower is visible from the side. I'm not going there. The problem I was having was that during fast weak hand reloads, (fast for me anyway) the shells would hit the flat spot on the receiver, just below the mag tube opening, and stop dead. sometimes it would go in, other times (most times) I fumbled it. I used a file for most of it, with the end of the file padded with electrical tape to prevent scratching the tube. It is much smoother now and noticeably faster. I could probably open it more but I'll run it for a while then see.
The velcro side saddle works well for port loading after bolt lock back, otherwise I use belt caddies (also from Choate) to load the magazine. I put a strip of adhesive velcro (the fuzzy side out) inside the caddy to keep the 20 ga shells in a little tighter. I could not find anyone to make 20 ga shell caddies.
A word of warning, most of these changes will void the warranty. My gun was working flawlessly before (and after) I made any changes.
Wish I could get a larger charging handle like the JM pro. I am looking for suggestions.
I have included some amature pics.