Re: OCW vs Ladder...
I think they both have merits. I have read many ideas on the subject and the two that stick with me are German Salazar and Bryan Litz. German was speaking of the problem with fantastic OCW loads that often produce fliers. His experience was that often times what's good for long range score was not the perfect ocw group. What I got from Litz was the problem of finding a particular load the left the barrel when the crown was a circle and not an oval and there are certain powder load combinations that will do that over a wide range of conditions (i.e. .308 FGMM). Now we add in the next variable that while the crown is oscillating from oval to round, the barrel is oscillating in a sine wave of some circular fashion.
Now from what I understand because I'm new to ladder tests is that the optimum is to try have the bullet leave the barrel when it's at 12:00 o'clock in it's oscillation. I'll quote from the second sticky (Powderin' It) in this forum.
<span style="color: #990000">"ENTER THE "NODE." The node is the very top of the wave and very bottom. For ultimate accuracy, you want your bullet exiting the muzzle precisely when it has flexed all the way up, STOPPED [for a nano second] before it begins it journey flexing back down. This is why you had a decent group or two during the ladder test, despite differing powder charges.</span>
And with all luck, the crown will be somewhat round and not oval at that point.
I find the ladder test interesting. I just recently did a 100 yard ladder test (Jered Joplin's advice from the Powderin' It thread) and I think one can find some worthy data in that type of test. I like it because 100 yards is handy especially for public ranges and it takes out some of the atmosphere variable. I did mine a little differently so I could see the wave more clearly across the charge spectrum.
Assuming the most accuracy with the lowest fliers can be achieved with a top node, I think the only way you're going to find that is with a ladder (and perhaps across different powders and bullets). If you're content with sticking to one powder, one bullet, OCW will probably be just fine. 3 different powders with 3 different bullets is a lot of OCW. I think the quicker path would probably be ladder.