Ossage

I used to shoot 2312s out of a 70# Mathews at 30" draw, though I shot mostly 100 grain blades. Don't know what the problem is. There are plenty of folks getting pass throughs with 40 pound hickory self bows. I think if one took that arrow weight out of a 60 pound bow everyone would say it was fine, just because 60 pounds is penty for anything, and it would meet a magical formula level. Arrow durability aside, therefore, what could be the problem? If the arrows were looking like exploded cigars, surely that would be mentioned. My prefered set-up is swaged arrows, and I don't have durability problems in these wall sizes. I agree however that heavier walls would be better when the going gets tough. On the other hand, from what I have seen, these shafts appear as strong as good cedar, and good cedar is more than strong enough, it also weighs in the same range.


How are forged risers made, and why would they have sand pockets, I thought that was for castings?

The one thing I don't like about forge/cast, is that it doesn't mean much as a process relative to quality control. Milled parts established a reputation when milling was all by hand, and the most expensive method. CNC has dropped the price, and also made it possible to have it all done out of house if you want, without any significant risk that the parts will be botched. If wandering through my mind is the picture of a bar of metal in a CNC router being chewed away at while lubricant sloshes all over the place, I am not too far off the marl.

With casting or forging, I can't quite see it in my mind's eye. They could be doing anything, with all sorts of nasty additives, or cheap processes, it all depends on the actual process. "Just trust me". Well it always comes down to that, but heck this is an industry where the one time leader buzzed their milled bows out of aluminum extrusions at 90 degrees to the appropriate grain alignment, "trust me" hasn't always been good enough with either material. I just have more confidence with milled risers.

bigbulls

Assuming that you are using the same broadhead, shooting both alluminum and the carbon arrow at the same speed, and they weigh the same the carbon will out penetrate the alluminum arrow.

Carbon arrows are stiffer which allows them to transfer energy directly to the target better, they recover from bending faster so they do not waste energy in side to side motion, and they are thinner so they have less friction moving through a target.

Now I'm not saying that this is why you did not get a pass through on deer as there are too many variables to consider but it could contribute.

PABowhntr

Arthur,

I am in awe. I must admit that was an absolutely excellent technical post and now I remember why I like you so much...

Thank you for that fine explanation. It reminds me of that component thread from way back when. Speaking of which......

Arthur P

LOL, Frank.. Nothing awesome about it. Before I was disabled, I worked 10 hours a day, six days a week in the aerospace industry as a machinist, quality assurance inspector and production planner. You don't do that much work with military, NASA and FAA specifications without some of it sticking to ya.

Ossage, brother you have hit the nail on the head. How in the world can someone shooting a 70 pound compound, with all that horsepower at their disposal, NOT get a passthru on a puny little deer? Tune the bow properly, make intelligent decisions on arrow and broadhead selection, put the arrow in the right spot and that deer shouldn't even be able to slow the arrow down, much less stop it.

There is a lot of reference material about forging on the internet. Do a search for 'aluminum forging'. It's the same technique they use for forging all non-ferrous materials. If you just search for forging, you'll wind up wading through a thousand blacksmiths before finding the info you want. One point where you are incorrect about forging... Today's techniques are so good that they can forge parts to within just a few thousandths of an inch tolerances. Quality is VERY good. And there is always the option to finish the critical areas of the part to exact tolerances by machining.

But you're right about another thing, not being too trusting. Someone can take a cast riser and drill a hole in it. Since drilling a hole is a machining operation, now they are able to call it a 'machined' riser.

But this stuff is getting a little too far off topic. I only got into it to show why I said temperature changes can affect a bow's tune and sight-in, which affects shot placement and penetration.

Trushot_archer

Damn Arthur...

Amazingly informative. I don't know why you hang out here with retards like me!

Seriously, I really appreciate the info.

So in a nutshell...I should buy a recurve?

Arthur P

Of course.[8D]

Cougar Mag

There is the problem!!! A 2312 is about the same weight as a 2213, and neither is going to give you proper penetration out of a 70 lb. bow.........I don't care how fast they fly.

Here is a challenge: I'll take my 65 lbs. @ 29.5" draw, shooting 2216's or 2315's, using the exact same broadhead, and get more penetration than anyone using a 2312 at 70 lbs.

ijimmy

2312's are great for short draw archers shooting targets at 50 to 60 lbs , that is untill they get bent , 2315's are much better for hunting , they dont flex as much upon impact . Carbons or acc's are even better for going straight into what they hit .

JeffB

I shot 2213's off a 74 pound bow that prduced 50 pounds of KE for a couple of years, and they weighed less than Tru-Shots. I zipped through every deer I shot at. I don't think the arrow shaft to peak weight correlation is the problem.

The problem I think is spine and in particular, shaft flex. The 2312 is definitely underspined for the bow in question, even though the shaft may recover due to adequate fletching control. However the arrow is probably expending too much energy recovering, and whipping severly upon impact. For alums you should be shooting a 2314 at 28" 70 pounds out of a MM.

One thing I have found is that you can get get good tears and decent groups with several different arrow spines from a single-cam bow, however, there is a "sweet spot" for spine and IME it's alway been a slightly stiff shaft.

This is of course is assuming there were not other factors affecting pentration in these particular cases.

I would suggest you invest in some properly spined arrows, say 2314's for alum, or something like an Carbon Express T-select size 60/75 or Easton Evolution 400, re-tune, and see what happens.

Trushot_archer

Thanks Jeff. I think that is the real issue. I don't understand enough about spine, so I just went with what the chart said.

That being said...is there any serious detriment to being overspined other than the weight/speed concern?