I have a 1955 vintage 99F in 250-3,000 in good shape, bought new by a shooting buddy who is now 91. He's not doing any more shooting or hunting at 91, so he sold it to me. It will shoot 87 or 90 grain bullets quite well, but for some reason won't shoot 100s worth beans. That includes short for weight 100s. Simple answer: Shoot 87s and 90s.
I carefully checked the rifling twist, and it is 1 in 14". I understand the twist rates can vary as the old machinery wasn't exact. Good luck with your new 99!
