I use the Hornady OAL gauge and comparator for bullet seating depths.

On all but the Hornady Interlocks (all without cannelures), I am currently setting (-)0.020" off the lands.

For the Hornady Interlocks with cannelures, I am currently going with Hornady's advice, which is to seat at the cannelure depth and lightly crimp. I very (very) lightly crimp on these with the LFCD. Talking with a guy this morning he said in his experience, guys who seat off the lands, ignoring the cannelure, have had mixed accuracy results so they recommend using the cannelure for depth.

In their manual, for the 250 grain bullets, they don't offer the SP-RP. Only the SP, with a COL of 3.310", and the RP, with a COL of 3.340".

For the SP-RP if I set the depth at the cannelure, I get a comparator reading of 2.660," and a COL that is much shorter than that of the SP: 3.240". I presume part of that is the difference in bullet tip shape between the SP and SP-RP.

3.240" is the shortest COL among all my loads for the .338, shorter than even my 200 grain Hot Cor's (comparator of 2.758" or 2.738", with 0.020" back). Does this setup seem right?

Note: Just checked SAAMI min COL, which is 3.215," so it seems we're in spec. Still wondering whether this particular depth (at the cannelure) makes sense.