I had Cal Pritchard of Pritchard Gun Repair in Thunder Bay thread the inside of the muzzle and i purchased 3 Briley steel rated chokes from him . He did an excellent job and with the flush fit you have to look very close to see that anything was done . I'm thinking that with the price of the three chokes and the threading i paid about $120.00 . I've tested patterns with my chokes against longer barreled shotguns with the same choke and there is no difference . I wasted about 30 bucks as the open choke is of no value to me . In fact i only use the modified shooting bowling pins and 99% of the time the full choke is all i use .
I e-mailed Brenneke to ask about shooting 3 inch fosters through a full choke and they repied , no problem . The fins on a Brenneke foster are not designed to impart spin nor stabilize . They are meant to swage through any choke .
Prtichard just ordered me 5 more boxes of Brenneke 3 inch mags @ $13.00 per box . I've taken a lot of big game with Brennekes and they work very well , all of the time so i don't mind paying extra .
I guided bear hunters for 10 years and never saw a Brenneke fail if it was put close to the right place . I've seen pretty much every other kind of slug fail at one time or another on bear so although it's just a personal opinion based on 10 years of observation , everyother slug is designated , whitetails only , for me .