Choke tightness

[mossyoakpro]

I just received a 550 IC from a fella on here...anyone had any luck shooting that tight of a constriction?  If so what loads? 

It's going to used in a Franchi Affinity with Mobil threads....

Thanks in advance....

[ads1]

Yep, used an Indian Creek .555 with my Weatherby xtra Green SA459. Best pattern ever, with APEX #9. Longest shot 44 yards, but it patterned at much longer yardage.