04-26-2023, 08:39 PM
Not knocking the OCW method by any means, but the best results I have been getting is with the optimal barrel timing method, via Chris Long.
In many respects I think the ocw works best when the cartridge has room for several nodes and loads... whereas the 6.5 grendel and 6Arc have much less powder space, so the workup range is more limited.
With CFE and bullet weight down to as low as 80 grs, there's room to do workups. I load a sinlge load-ladder of 0.3 grs delta over the range I can do for thepowder/bullet (hornady data), then plot on a graph, to examine where to concentrate. For 24" barrrel I can suggest MV's to concentrate your look-around, so build some 4-round loads at those charges, I don't worry about actual zero yet, until after I have found the powder wt and do perhaps seating-depth range of ~0.010 per step. Best grouping depth of the best-MV/SD combo gets the vote.
About the plot, in a mechanical system I expect the powder/MV graph to be close to linear, a well-behaved system ought to increase MV as powder charge increases. Once you have a node it will self-perform fairly tolerant of any powder changes, mine go no more than 0.1 or maybe 0.2.
Example, my 22" unitah (bolt action), shoots the 103 eldx at 2733, sd around 6. Not the highest node but a consistent one.
I adapted my approach from Chris Long's work (on the web) on OBT, and acoustic wave theory.
In many respects I think the ocw works best when the cartridge has room for several nodes and loads... whereas the 6.5 grendel and 6Arc have much less powder space, so the workup range is more limited.
With CFE and bullet weight down to as low as 80 grs, there's room to do workups. I load a sinlge load-ladder of 0.3 grs delta over the range I can do for thepowder/bullet (hornady data), then plot on a graph, to examine where to concentrate. For 24" barrrel I can suggest MV's to concentrate your look-around, so build some 4-round loads at those charges, I don't worry about actual zero yet, until after I have found the powder wt and do perhaps seating-depth range of ~0.010 per step. Best grouping depth of the best-MV/SD combo gets the vote.
About the plot, in a mechanical system I expect the powder/MV graph to be close to linear, a well-behaved system ought to increase MV as powder charge increases. Once you have a node it will self-perform fairly tolerant of any powder changes, mine go no more than 0.1 or maybe 0.2.
Example, my 22" unitah (bolt action), shoots the 103 eldx at 2733, sd around 6. Not the highest node but a consistent one.
I adapted my approach from Chris Long's work (on the web) on OBT, and acoustic wave theory.