Aiming "off hair" is always a "bad" thing, be it rifle or bow. Are you using Hunter's cedar arrows?

Paul

I have been shooting carbons but last night I tried some Easton 2312 aluminums. The fatter arrows helped too. If you break the line you get the higher score and I picked up several points that I wouldn't have gotten with my carbons.

Yeah, I remember the "fat arrow" concept with respect to scoring.  I'm surprised to hear that you actually 'scored' as a result.

When I shot aluminum shafts, I used 2117s because they were the lightest-spined shafts I could shoot from a 65-70# draw bow.

I did quite a bit of "muzzle velocity" testing on arrows, and in the end the conclusion was crystal clear. The ONLY thing that matters to arrow speed is arrow weight. If you wanna go faster you gotta go lighter. Once I started shooting carbon shafts - with the same weight "law" applying - I got the smallest diameter carbon shafts I could find and put the lightest points on that I could find. At that time - I don't think it matters legally anymore - the arrow had to be no less than 435 grains in total weight. I THINK they have eliminated that requirement for big game arrows in Alaska. I'm sure there are still "distance cast" and length constraints, but I don't know/recall what they are nowadays. I do know that I am "legal" with the arrows I shoot. Beyond that, I don't care much what the regulations are.

Paul

I measured the aluminum arrows and they are 0.367" my carbons are 0.290". That makes a difference.

They're supposed to be 23/64 = 0.359375" in diameter with a wall thickness of 0.012" - hence the nomenclature - 2312.

Paul

These are the rentals that get used and abused by lots of kids so it's entirely possible that there was a bend or something where I took the measurement. But that's quite a difference, almost as much as a 7mm vs a 358.