so I just recently bought a new bow. (its a diamond core by bowtech). my old bow was only 60 lbs @ 29 inch draw and my new bow is 70# @ 29 inches. the arrow im shooting have 400 vanes. anything inside of 20 yards my groupings are pretty tight. but once I get to about 36 yards and above the accuracy drops and my arrow flight starts getting wild. before I try making any adjustments to my bow, does the issue have to do with my arrows not being the right match for my bow? that is what im thinking but I just thought I would see what everyone else thought.
You are under spined. If your arrows are cut 28” from the end of the carbon to the other end of the carbon, you need to be at least a 340 spine if you are shooting 100 grain field points or 100 grain broad heads. If you add extra weight up front as far as brass inserts or weights that screw in to the back of the aluminum insert, that extra weight further breaks the spine of the arrow down. Most brands of arrows have a spine chart on their websites
a lot of people just aren't as accurate as they think they are at ranges like 35+ youve upped your poundage 10 pounds, could be you (dont take offensive) could be spine based on increased poundage i can shoot well at 20, 25, 30 get me out any further and im not very good. its just harder to shoot "longer" ranges. add extra muscle tension, grip issues, new bow maybe not perfectly balanced...
John it could be a lot of different factors. According to the spine charts you are under spined but there could be other factors. When your groups start to decompose is there a pattern? Are they taller, wider or just erratic? Have you done any center shot tuning with the new bow, paper, walk back? If not I would start there before changing your arrows just yet. Even then be sure to shoot your broadheads because a spine issue will rear it head there in lots of cases. Keep us posted.
I think it was the arrows. Here is two at 40 yrds. Also bought a new sight. It’s a trophy ridge single pin. Still getting used to it but I think I’m gunna like it