I am using the FF limbs, 55lbs. and 60 lbs. on my B mag riser. I use a skinny string also. So far (1 yr. ) no problems. I intend to use the 55lb. limbs agian this year to hunt with.
It seems Bear did not have the same problems that other bow companys had with mag handles breaking from poor castings. Also it seemed to be the early cast compound bow handles that broke. Hope this helps.
Tom