Tuning-weak=false stiff??

[the rifleman]

I have two Toelke Whips--one is a 58" 43 pound w the older limbs the other is a 62" 42 pound w the new high speed (HS) limbs.  I shoot left handed.  Both bows want very weak arrows and I have been able to get the 42# tuned w 75 (.670 spine) heritage full length w 125 up front.  Full lenght 600s are just a bit stiff and i have to load them up w 200grs-(more weight up front than I want)  Today I decided to try to tune the 1716s to the 42# HS Whip w 90gr up front.  I knew they tuned weak before so I began cutting and got down to 27" (shortest I can go).  Sometimes they hit center, some times they went about 6" right (stiff) and sometimes they hit 18" left (weak).  Could this be a sign that these arrows are much too weak for this bow?  I wasn't sure if very weak ever caused a false stiff.  I have had good success bareshaft tuning carbons, so I do trust my form, draw length and release and I made sure that my nock fit was good.  I never heard any clicking or sound that would indicate the shaft bouncing off the shaft.  This has me puzzled.  I do all of my tuning bareshaft.  I have no 1816s--if you think the 1716s are too weak and causing this erratic flight would 1816s likely be the answer?

My wife shoots 27" bop 1816s with 145 grain heads out of her 42@28 NAT and draws about 26%1/4" .  I don't know how they bareshaft, I never do that, but with  three 5" feathers they are perfect.   She prefers 40-43 tapered cedars with 125 grain heads.  I have a friend that likes one of his lighter bows, he had confusing readings with full length carbons as well.  It seemed that arrows reacted to every little variance in his shooting.  We tried some tapered cedars and he has not shot anything out of that bow since.   He stalked this one with that set up.

[nhbuck1]

shoot them through paper

[the rifleman]

What would paper tell me that my bareshaft method doesn't?

[mec lineman]

I got a new longbow that is not cut close to center as my other bows.I currently shoot beman 500 of different lengths with 250 up front. I am right handed and my arrows are showing weak bareshafting but my fletched arrows are hitting left. Bareshafts are showing false weak.