Ladder Method for Best Load

[mattj]

To OP:

For what it's worth, I haven't used the 'ladder' method, but I've had excellent luck with its cousin the OCW method: Dan Newberry's OCW Load Development System

I pick a known "good" powder/bullet/primer combo from research on forums like this, then:

Session one: I do OCW as described in the link -- 5 rounds each powder charge in a round-robin fashion. I use chrono information to help interpret what I see on target. I also find OnTarget software ( On Target Precision Calculator ) helpful -- usually I will dump the chrono information and the "center of the group" Y-axis measurement from point of aim into a spreadsheet and choose my 'winning' OCW charge based on the info there. It is pretty cool to graph the information -- when you let Excel interpolate curves between your data points, the sweet spots show up pretty clearly.

Session two: I shoot 5-shot groups in .005" seating depth increments, starting .020" from the lands, and ending touching the lands (assuming the load isn't right near the max). Like OCW, I shoot in a round-robin fashion. Unlike the OCW phase, here I'm looking for tightest group.

I could certainly add more steps here -- for example, doing another couple sessions where I refine the powder charge and seating depth down even further -- but so far the above sequence (takes ~50 rounds and two trips to the range) has not failed to give me consistent sub .5 MOA loads.

Matt

 

[boomtube]

mattj, I think your system is an excellant next step AFTER the Ladder Method shows the better ranges of powder charges to test.

I mean, it ain't, "This and this only" for any evaluation method, is it?

 

[mattj]

mattj, I think your system is an excellant next step AFTER the Ladder Method shows the better ranges of powder charges to test.

I mean, it ain't, "This and this only" for any evaluation method, is it?

Certainly isn't a 'one true method' -- and I think one should use what they are most comfortable with -- just sharing what I do.

That said, I haven't seen any need for a 'pre-OCW' step... The range I use is one step "up" from published max charge (which I only actually fire if their are no pressure signs at the lesser charges), down to about 90% of the max charge in 2-3% increments. I've never not found at least one OCW sweet spot in that range, and I've always had good final load results using that node.

Of course, I've also never delved into the realm of developing loads for wildcats or working with powder-bullet combinations where there isn't lots of published load data -- in those cases, I can certainly see where working a ladder first to find a starting place for OCW would make sense...

Edit: I also don't care to push the envelope of published "safe" load data -- if you are pushing much past published maximums with a custom rig or something, finding the pressure limits with a ladder or something first would probably make sense.

-Matt

 

[4xforfun]

Who packs that 'free lunch' up the mountain?

AJ

So, you LR hunting rig only has an 18" tube?