COAL/seating to lands question for the pros

[Dentite]

Some background...I'm working up loads for the first time and could use some advice.

I've loaded up some test rounds for a couple different bullets in .223. The first set were 69g SMKs seated .020 jump to the lands. The second batch was 52g SMK seated .040 jump to the lands (the 52g would not seat to .020 due to not having enough bullet in the case to reliably keep COAL).

I've zeroed in what powder charges are giving the best accuracy and now I'm ready for the next loadings.

My question is this:

When you start to zero in on a charge that the gun shoots well do you then start to experiment with COAL (and hence differing the jump to the lands)?

Seems you wouldn't want to mess with COAL changes until you zero in on what powder charge the gun shoots best.

So I guess my plan at this point is try to load a few more test rounds with smaller increments to fine tune the powder charge and once I establish that I then might try the same powder charge at differing COALs (increasing the jump...I don't want to jam to the lands).

What do you guys do?

Thanks,

John

 

[oldfortyfiveauto]

If possible I first try all loads set to touch the throat. If things look promising I'll try backed off in .010" increments.

 

[djthemac]

I usually run the ladders with various powder increments until I find the correct node, and then I mess with bullet seating depth. I have the Hornady comparator and OAL gauge, so I know before starting the jammed measurement.

Some people recommend starting out running ladders jammed. This makes sense as you will find the max load for your loading and can back off the lands after you identify the nodes. The alternative is to find your max pressure loading and run the risk of accidentally jamming and causing a pressure spike as you adjust COAL