Spine/Bareshafting Question

[eagle24]

I've been trying to get my bow/arrow setup down with my 52# ACS-CX (right handed).  I had been shooting Gold Tip 55/75 traditionals and recently purchased some Beman MFX Classic 400's.  I was shooting the Bemans indoors for the past several weeks and thought they were flying good.  In reality, I could'nt see the arrow well enough indoors and it was not until shooting outside, during daylight hours, that I discovered they are not flying as straight as the Gold Tips.

I bareshafted the Bemans with 125 & 160 grain field tips and get very similar results with each tip:  the bare shaft seems to curve slightly right and impacts the target nock left every time from any distance 3-20 yards.

Does this indicate weak spine?  I have a hard time believing that a Beman 400 is weak for my bow.  Most of my friends are shooting 500's from similar speed bows.  I'm wondering if the smaller shaft diameter is putting the arrow past center shot and that may be causing the nock left condition.

I would like to hear your thoughts and suggestions.

[shootrmn]

I am shooting the bemans you mention with 125 points and they did the same thing bare shafted but they fly great with my 4 fletch on. I also found that I needed to raise my brace height to  7 1/2 inches to get them to fly like the hex shafts I had been shooting. Now My bemans, and my gt's are all hitting close together.

[R H Clark]

It would seem if they are windplaning right bareshafted they are too weak. Can you cut them shorter or raise brace height? Don't raise brace unless you are within the limits and don't get too much vibration or noise.

Before you start cutting you might raise the nock just to be sure you aren't hitting the riser and getting a false reading. If you are still windplaning right but are just more nock high the shafts are too weak.

Cut about 1/4 in at a time until you are getting good flight. If you are still hitting right of your aiming spot build the sideplate out a little.

I'm no expert but that is what has worked for me in the past.Good luck .

[katman]

RHC is right on you are weak in spine, carbons spine don't react quickly to point weight change but react VERY quickly to length change. If you are already close bareshafting you might try 1/8" at a time. My Axis bareshafts the same with 100-250 gr field tips, thats a lot of weight change but doesn't effect impact point much if at all, all the different point weights papertune right on.

[eagle24]

This is really surprising to me.  I agree that the bareshafts are acting like they are weak spined, but I never would have thought a 400 would be weak out of my 52# bow.  I can't cut them any shorter (30"BOP) and shoot broadheads with them, but I will experiment with building the rest out and also changing the brace height.  I've got room for a higher brace height.  In fact, I happened to check it yesterday and It was at the bottom of O.L.'s recommended range for the bow.

[Bjorn]

It is surprising how much stiffness the ACS wants; and it may be the degree of cut past center. I found mine to be super quiet at the low brace and some noise when higher. So I kept the brace at 6 3/4 and built out the side plate to get good bareshaft flight, and that worked well for me. Don't know about carbons; but I'm shooting 75-80# woodies from my 49# ACS