MichaelT.

Last post PPL tried to help me and answer my question, which I appreciate, but I apparently did not give enough information. Here it is again, with info asked for, if someone would not mind trying again. Thank You ahead of time for the assistance.

I am shooting a PSE Firestorm Lite, rated at 300 IBO. I was shooting 72 lbs., with a 28 1/2 inch draw, carbon express 400's, Blazer vains, muzzy 3 blade 100 gr., through a Whisker Biscuit, Cronyed out at 256 fps. We dropped it back to 55 lbs. and it is shooting 230 fps. Does that information help more.???? I am not grouping well, and the arrow seem to be going in at abit of anangle with the knock to the left of the tip. Are my arrows over-spined now since I dropped back to 55 lbs?

BGfisher

You should easily be able to shoot a 400 spine up to about 65#. Getting up around 70# it is going to be underspined or at the very upper edge of the charts. I question why you would drop clear down to 55# though.

My experience with carbon shafts is that they will shoot well even if grossly overspined. I've shot a 300 spine at 27" that tuned well down around 53#. You can't just drop from 72# down to 55# and expect the arrows to shoot the same. It calls for a complete retune. And with such a short axle to axle bow everything is going to be a bit more critical to any form flaws.

Most likely you're going to have to play with the centershot some. If you don't have one you would be well served to download the Easton Tuning Guide from their website. Try walkback tuning and then broadhead tuning.

MichaelT.

BGFisher,

I understand your confusion on this subject. I recently posted the changes to my set up asking for help because I am in no mans land. I just had neck / spine surgery last thursday. I have reset my bow because I would not be able to draw 72 lbs. when the DOC. releases me. I am having to reinvent the wheel, so to speak, for after my recovery. Thus the 55 lb. weight. I wanted to honor the deer by getting the set up as "right" as I can, and when the doc. says I can hunt I will be ready and running out the door. The last thing I would want to do is go out half cocked, and poorly tuned, and "hurt" the animal. So I am tring to make sure I have done my part. When I looked at the idea of 400's at 72 lbs. shooting pretty well, verses 400's at 55 lbs. and the way they were flying, ( not bad but not great ), I began to wonder about the arrow spine. This is my attempt to see if that could be the problem. Thanks for the input.

BGfisher

Mike,

That sufficiently answers my question. I've had two neck and one lower back surgery so I can relate. Been out of town for a while so didn't catch your other posts.

I laud you for wanting to be "ethical". I guess you'll be hunting whitetails so frankly you should still have enough peak weight. In fact I hunt with about 56# myself.

I know most guys get all hyped up about the speed that most modern bows get and the resultant KE, but believe me, I was hunting with compounds when 200 fps was a very fast setup and still managed to get complete pass throughs 30 years ago. It's mostly about good arrow flight and sharp broadheads. Of course, accuracy still being key.

One thing I just caught from your first post here is that you are using Blazer vanes. Because of the drastic weight change this might be part of the problem. You might refletch a couple with 4" vanes or feathers and see if this helps--if you have a fletching jig. If not then maybe buy a couple arrows already fletched with same and try them. Could be you just need a little more stabilization on the back end of the arrow.

I'll be keeping up with this thread and I wish you luck with the neck. By the way, was it a laminectomy or what?

MichaelT.

My right arm and shoulderwas hurting terribly at times, with musclespasms, and a lot of pain between my shoulder blades. After several tests, neurosurgeon found nurve pathways at c 5 , c 6 , and c 7were completely blocked off by an extreme disc herniation - which did rupture before the surgery.... and large bone spurs which he had to grind out of the vertebrae. Go Figure... now arm hurts like hell because the nerves are starting to comeBACK to life...MY luck...but I am on my way and I hope to soon be holding my bow again. Thanks...MET

Paul L Mohr

Yep, that's stiff. I showed them being stiff at 72 as well. That is assuming you have 28 inch arrows. If they are longer they would be a bit weaker.

I agree with BG though, carbons tend to shoot pretty well when overspined. I also agree anytime you change something you need to retune to that set up.

Paul

MichaelT.

Well thanks for the info, I thought I might be overspined, but with that said, if I may ask, what should I be shooting for that rig?

bigbulls

Carbon express rates their arrows opposite of Easton/ Beman. A CX400 is the stiffest shaft offered in the Carbon Express line (about a .290 spine). These arrows are extremely overly stiff for your set up. A CX400 would be the proper arrow to use if you were shooting 75 - 80+ pounds, had a 29"+ arrow length and were using 125 grain tips.

You should be using a CX 200 at 55 pounds. I figure with the whisker bisquit you arrows measure about 27 inches long and assuming the popular 100 grain tip.

You may also need to adjust your center shot slightly and your nock height.

MichaelT.

Thats what I needed, Thank you sir. New arrows will be purchased tomorrow. Good luck and Great hunting.

BGfisher

Bigbulls is right and I should have caught the fact that you are shooting carbon express. As far as I'm concerned there should be an AMO standard for marking the spine on arrows. For what it's worth I think Easton/Beman are the only ones marked correctly, marking them with the actual spine deflection in inches.

That's the reason you have to always check the charts before buying arrows and do a little interpolating. So although I was right in my thinking I erred in not cross referencing my numbers to the carbon express. I'll try to be more astute next time.

And for what it's worth you just might get used to that lower poundage and enjoy it better.

Good luck with the healing process and don't overdo it.