I shoot the same gun and while I have not used the .690 restriction choke I have used the new carlsons Winchester longbeard choke which is .683 restriction. With the 3.5" long beard 6's I get in the 220 range, with 5's I get in the170 range, and with 4's I get 120-135 hits. These results are in a 10" circle at a lasered 40 yds. I have also tested the factory choke which I believe is .695 restriction which yielded about 30-40 fewer hits with 4's, 5's, and 6's. I've tested other chokes but these are the only two that's close to your setup. Hope this helps and I'd be glad to share my other choke numbers if your interested. Just for the record. I'll be using the long beard 4's this season with the .676 Hevi-13 choke which puts over 160 hits in a 10" @40. I also agree that the .670-.676 range would probably yield the best results .
