Seems the current trend in bow tuning is bare shaft tuning compound bows.
An example is a photo where someone shoots a 10 with the fletched and a left 8 with the bare. The suggestion is often "Arrow spine is too stiff add point weight"
Now its easy to dismiss these things so I always like to test them.
My thing with tuning tests are this.
Can I repeat it?
Can I do it backwards?
For example will an arrow with a stiff spine do the same thing?. Will a weak spine arrow do the opposite? Will I see a result if I follow the instructions? Will I see a different result if I do the opposite?
"Shoot 4 different arrow setups. 3 of different spine and one with a different point weight"
"Don't change the bow"
"Will a stiff arrow impact left and a weak arrow impact right?"
"Will change of point weight change impact position of bare shaft horizontally?"
Base point. Arrow is 400 spine. 120gr point. Shot from 54lb Prime STX 36
Arrow impacts left of group
Test 2. CX Nano Pro 500. 120gr point. Arrow lands much further left of group.
Test 3: CX X-Jammer 27. 290 spine 210gr point. Arrow lands a little more left of group than 400 spine but not as far left as 500 spine.
Test 4: CX X-Jammer 27. 290 spine 295gr point. Arrow lands same distance away from fletched arrow as with a 210gr point
Left impact does not indicate spine of the arrow. The impact pattern was
The change of point weight had not bearing on left-right impact.
Bareshaft tuning seems to be an unreliable method of determining if your compound arrow spine is correct.