Have you heard of Stu Miller´s Dynamic Spine Calculator? According to that, you would need about 300 grn at the tip to make them work with a 55# Martin Hunter (the Saber is not on Stu`s list). The best would be, I think, a custom-made, lathe turned insert that would add about 150 grn and at least 1 1/2 inches at the tip. If you can make those yourself, it would work...but if you have to pay for it, it is probably going to cost more than a bunch of new arrows, I guess...just my two cents.
DF