(05-01-2024, 02:20 PM)grayfox Wrote: Now you know what the real-world MV response for your barrel and your combination should be. From this you can look for a range that is close to a node (as defined in "optimal barrel time" - see Chris Long).
For a particular obt node (this is based primarily on barrel length and MV, not powder or even the bullet!), pick a range surrounding it and shoot 4- or 5-shot groups at 0.2 intervals. Again chrony and look for the best SD and tightest MV average. Not worried about actual group size (remember I'm less than a perfect shooter anyway!). That's your target load/MV for that combo.
So, to estimate node time => (barrel_len(ft) x 2) / mv ?? so, barrel = 1.5’ mv = 2560 =>
1.1718 ms ☹️ that is beyond 7th node.