bump your spine up and put more weight up front to avoid the tubs. I used to shoot 35/55 with 250 upfront 29" long at 540 with trads and 490 with hunter finish. After my first trip to africa, I realized that more weight would help for the next trip, so I experimented with tubes, keeping them long, glueing them in and could never get 100 % rid of rhe rattle noise although the nock problem. Since then, I started shooting GT 55/75 with 300 upfront, 30 inches in length for a total weight of 590 in the hunter finish with no noise what so ever.( I haven't tried trad finish but I think about 650 grains, too much for my 52 lb. bw and 50 lb. bob lee.)