I have 2 Browning B80s. The first one I bought in about 1981. It was a fixed Modified choke. It was my primary shotgun for 10 years, many of those years we could shoot lead at ducks, which it did a lot if.
The second gun I bought in about 1991, used. But that model was only available for about 5-6 years, discontinued in the mid/late 80s.
The newer gun had an alloy receiver and the original “invector” chokes, really short chokes.
The original fixed modifies chamber has had AT LEAST 200 Hevi-shot, 10,000 steel shells and 20,000 lead shells through it.
I bought aftermarket Carlson extended chokes for the “invector” choke barrel.
2 days ago I shot some patterns with both guns, and a couple different chokes in the “invector” choke gun.
I thought the fixed modified was worn out and was probably IC at best.
So I shot 1 1/4 oz #6 shot in 2 different loads, 1385 fps and 1440 fps.
The adjustable choke with “light modified” put 129 pellets in a 26” circle, average if 2 shots.
The adjustable choke with “improves modified” put 162 and 160 pellets in that 26” circle.
The fixed modified put 183 and 179 pellets in the same circle.
I haven’t noticed any reduced recoil in the longer chokes, but maybe I’m missing it.
I did learn that the difference in velocity didn’t really make a difference.
And I learned that my fixed modified shot a significantly tighter pattern than an improved modified on the other gun so apparently all that wear hasn’t opened that choke up.
I’m a Boss shotshell fan for bismuth. Bismuth has a reputation of being extremely brittle. If you push it too fast, urban myth has it that it crushes during setback and at the forcing cone?
Since I live in California, I have to shoot non-toxic on everything. I used 1 1/4 oz, #5, 2 3/4” Boss bismuth last year for California chukar, and waterfowl. The bismuth took Canadians, specks and ducks as well as my old 1 1/2 oz lead #4s did. I was impressed.
I hunt chukar primarily in Nevada so lead is my go to there.
I have a California vest and gun with the plug in strictly for California loaded only with bismuth. And a Nevada gun/ vest strictly for Nevada with the plug out and loaded with lead.
Unfortunately, Boss is mail order only and being a California resident, that’s a strict no-no. I would never recommend anyone to do a work around a law, regardless how ridiculous the law was. But IMHO it’s worth the $2 a shot it costs. Hence why I hunt Nevada more than I hunt California.