I've heard a lot of recommendations on here for the Hevi choke out of an Extrema. I read a lot about it last year while doing research for my Extrema 2. I ended up ordering some Nitros and purchased a .668 Jellyhead from Nitro Co. to shoot them with. Otherwise I would've gone with the Hevi choke. I ended up shooting H13 6's through the JH choke with good results. I never counted, but i was probably around the 200 mark. I do know I misjudged a bird last year and killed him stone dead at 58yds. I don't believe you can purchase a JH .668 over the counter, I did try a friends JH .660, and I wasn't impressed. You may wanna give Nito Co. a call and see if they still offer this choke, it was the choke they recommended to me for the 2 7/16 oz load, which they also recommended. Also, the Hevi 13's, performed better than did the 2 7/16 oz Nitros. I think it was around $50-60. Just another option you may wanna check out.
