GD,
i define fast as using the same weight arrow at the same DW ofcourse.
When you shoot a variety of different setups- its easy to compare setups and arrow speed with ILF- i rarely even setup my chrono anymore…instead I compare my gaps and trajectory At different distances As thats what matters to me.
When my PO is about the same but my gap at 20y goes from 3/4” to 1/2”, thats a significant difference in drop- thus much faster.…and correspondingly its more accurate.
The whole miss faster comment I’ve heard the very heavy arrow crowd claim is BS.…. otherwise, all of the 3D guys would be shooting Slow bows.
Personally, I am concerned with the pointability and bow noise as much as trajectory so its not all speed.
I experiment, a couple examples;
I have some Dryad ACS longbow limbs I can compare at the same weight on the same riser. They are significantly slower than Nika N3’s and Selenghas- its no contest.
developing a hunt arrow for my 53# recurve that bare shaft tunes I had 3 options;
( weights are appx by memory)400 spine 370g, 350 spine435g, 300 spine500g
The lightest arrow was a rocket ship, trajectory was amazing but it was a little loud. The heavy arrow trajectory was soso- about what I had been using prior.
After shooting the 435g for awhile, quiet and it had better trajectory with less holdover at those medium 20-25y distances….but more importantly, my accuracy/ groups improved.
You can always get a little more speed by dropping down in arrow weight.