The OCW (Optimal Charge Weight) Method Explained

The OCW method hunts for a forgiving charge: you fire round-robin groups across several charge weights and find the one where the point of impact barely moves as you step the powder up or down. The theory is that a charge that’s insensitive to small powder changes will also shrug off temperature swings and metering variation — so it holds zero across a season, not just on load-development day.

Developed by Dan Newberry, OCW is less about the smallest group on the day and more about repeatability: a load that lands in the same place whether your powder throw is a touch heavy or light, or the afternoon warms up. Here’s how it works and how it differs from a velocity ladder.

How the round-robin works

Load a few rounds each at several charge weights in small, even steps — always start low and work up, watching for pressure. Set a separate aiming point for each charge on the same target board. Then shoot round-robin: one shot at charge 1, one at charge 2, one at charge 3, and so on, then back to the top for the next rotation. Firing in rotation is the whole trick — any change in wind, mirage, barrel heat or your own hold spreads evenly across all the charges instead of piling onto one, so what’s left on paper is the effect of the powder, not the conditions.

What you’re looking for

Line up the group centers by charge weight and look for two or three neighboring charges that print to the same point of impact — a little cluster where bumping the powder up or down doesn’t move where the group lands. That charge in the middle is the “optimal charge weight”: the one least fussy about a small powder change. Notice this is about where the group goes, not how small it is.

OCW vs a velocity ladder

They’re after the same goal — a forgiving charge window — through different windows. A velocity ladder looks at your chronograph for a flat spot where velocity stops climbing; OCW looks at the target for a spot where point of impact stops moving. Velocity consistency and point-of-impact stability usually travel together, but not always, which is why plenty of shooters do both: run the ladder over a chronograph for the velocity story, and read the groups for the point-of-impact story.

The honest catch

OCW controls for conditions better than most tests, but it still leans on small groups and a fair amount of eyeballing — deciding which group centers “line up” is a judgment call, and three shots per charge is a thin sample. The round-robin is a real strength; the reading is where people disagree. As with any method, the fix is the same: use it to find a promising charge, then confirm your finalist with enough rounds to trust it.

Where Loadscope fits

Loadscope takes the eyeball out of the read. It measures each group from a photo — point of impact, mean radius and vertical — lines them up with your chronograph velocities, and scores every charge to name your best load instead of leaving you to judge which centers cluster. Whether you shot an OCW test, a velocity ladder, or both, it reads the same data and gives you a number instead of an opinion. See how the scoring works →