ok distance to the lands is 2.869

start at 2.849 ? Is this the magic .02 starting point. sorry math was not my thing

Essentially yes. The math is correct. But which bullet and round are you loading this for? Different bullets have different sweet spots for jumping to the lands.

beat me to it

Yup what Chad said

I always liked to start .005" off the lands ( single feed ) and go deeper gradually till I find the sweet spot.

If using magazines, i seat as long as it fits the magazines and go deeper if need be to find the sweet spot.

I start 0.010" off of the lands as long as that will fit in the mag, or reduce down to 0.010" below mag length if needed.

Shoot three shots of each charge weight on the ladder at 200 or 300 yards and the best load is usually very apparent.

Moving to at least 200 yards really improves the quality of information.

Many loads can look ok at 100 and really start opening up significantly at just 200 yards.

Final loads need to be tested to at least the maximum anticipated shot distance, as groups can open up farther out.

Any load that produces tight and accurate groups at long distances will be good at short distances, but the converse most definitely is not true.

The ladder charge weights typically are loaded 0.2 grains for the last two grains up to max, or 0.3 for a high volume case like a 338 Lapua.

Below that, each step is one shot at 0.3 increments starting at least three grains below max just to work up and make sure there are no excessive pressure warning signs.

I have tried several different methods of load workup and found this method of at least three shots to produce the most reliable and repeatable loads.

Also, three shots at each powder level reduce the influence of the driver nut coming loose now and then.

Quick question-will seating depth change which load may be more accurate? Could 42.4 .010 off be more accurate than 42.6 .010, while 42.6 .020 off be more accurate than 42.4 .020, but not more than 42.4 .010?

QSYB,

it can, but not necessarily. Only change one variable at a time during testing so that each variable is isolated and optimized..

I have settled on starting with bullets 0.010” off the lands, and change only the charge weight.

That usually produces a good load. If it does not, then the best powder weight is held constant and seating depth tested changing 0.020” with three shots at each length.

Agreed, though my numbers a a bit different. .005" off the lands, as long as I fit in the mag. Find the best charge, keep it, then change seating depth in .005" until it gets better. I rarely have to go mess with seating depth, though.

Once, Judd was loading two rounds, hand them to me, and I'd shoot them. If they weren't very close together, we moved on. Once they tightened up, we kept going. Eventually they opened up again. We went back to the best shooting "jump" and he loaded 5 rounds. That was the winner. This was all done at 200 yards.