OK, here is my dilema... Right now I am shooting my PSE Vengeance Hybrid (70 lbs) at 244 fps with XX75 Break-Up Arrows. The arrows weigh 529 grains. Now this set up is pushing almost 70 ft. lbs. of KE. This is all fine and dandy with me, but I was thinking about it and I really don't need that much KE for hunting deer. What I was wondering is the a lighter aluminum arrow that I could shoot so I would be gaining speed and have a flatter trajectory.
I really want to stick with aluminums because I just like them. The other restriction I put on my selection is that I want to keep the wall diameter (ie xx"15") at 15 or higher so it keeps the thicker wall.
So my question is there any aluminum arrows that I can shoot with a wall diameter higher than 15 that weigh less than my 2315's??
I was looking at like a 2117, but I don't know if I could shoot that or not.
Any suggestions??? Thanks in advance.

according to the chart your 2315 weigh 11.67 gr per inch and the 2117 weigh 12.02 You would be increasing your weight not lowering it.

http://www.eastonarchery.com/

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Try a CX 300 or GT 5575 and I think you'd be amazed at the increase of speed and KE, not to mention the incredible durability you'd gain.

Your KE will be about the same with different arrow choices. If you want to shoot a Gold Tip arrow that weighs 400 grains, you will still get about 70 KE. You cannot change KE by changing the arrow weight. You need to increase or decrease speed, but you cannot change the arrow. You will get more KE by increasing your draw length and you draw weight, and less by decreasing your draw length and your draw weight, not by changing your arrow weight.

yeah aluminum arrows lick hairy choads!!

Easton Acc's all the way 3-60's or 3-71's there expensive but there the best.

Oh contrare, mon freir......my formula tells me that KE= mass(arrow weight)x speed x speed divided by 450240. There is a happy medium with weight and speed, they work together. At some point, the KE reaches its limit, both with weight and speed, and will begin to drop off. In other words, by dropping arrow weight a little, changing nothing else on the set up, should result in more speed, and, perhaps better KE.
But, the heavier arrow will carry more momentum down range, and if you ask some of the old salts around here, they believe that is more important than KE anyway.
You may want to try a 2413. They weigh about 35 grains lighter, but should result in better speed. The trick, IMO, to KE is to get the heaviest arrow you can flying as fast as you can.

I thinks you guys might not have fully understood my question.
-I have plenty of KE...What I am looking for is a lighter aluminum arrow with a wall thinkness of at least 15 (ie. xx15). I am really not to concerned about KE because I have so much..I was looking to get a lightewr arrow that would fly faster, so i would have a flatter trajectory. Hopefully this better explains it. Who knows, maybe there isn't an arrrow to fit the bill...ohh well thanks for any help you can give.

Stick with the 2315's. There is no other arrow with a .015 wall thickness that is lighter than 2315 and also properly spined for your bow. If you want lighter and still have durability, you have to go carbon.

A rule of thumb about aluminum arrows might help you. The size numbers specifically spell out the shaft's outside diameter and wall thickness but also can be used to kinda get an idea of what two different arrows would be like. The first two numbers are more related to spine, like a 2315 is spined heavier than a 2115. The second two numbers are more related to weight. Like a 2219 is heavier than a 2215. It's not 100% foolproof, but it generally holds true.

So, if you're looking for a lighter aluminum arrow, you have to look at arrow sizes with the second two numbers lower than the one you've got. On the other hand, one rule of thumb that always holds true for aluminums is, the smaller the second two numbers, the less durable the arrow is.

You might look at a 2215 or an acc 429