SmallCaliberCentral

I'm using RL 10x and 39 SBK's



I'm confused as to where I should begin my reloads with regards to COAL. If I try to load factory COAL of 2.250, I will be .180 off the lands , That seems a bit excessive to me

My measurement to the lands is 1.955 OGIVE

Would 1.865 OGIVE be a good place to start. That's .090 off

Or 1.905, say .050 off the lands

At 1.955, I still have quite a bit of the bullet in the case, could I just start there?

Help

When starting with a new load, I empirically set my bullets .020" off the lands. Then I find the load that grouped the best and start adjusting the free bore from there. I recently started using Sierra 39gr BKs with BL-C(2) and I found that my gun likes a jump of .040" the best, with that bullet. At .050" things really started to open up. Kind of crazy what one one-hundredth of an inch will do! V-Max bullets seem to do the best in my gun at .060".

From what I've read here thru the years, factory throats are quite long. If it is a LTB, I would just load it to the max OAL per the book and start from there. If it's a VLD, they can be finikey to bullet jump.

HTH

Seems all the factory chambers have long throats,regardless of manufacturer.With the Sie 39 BK I have best results around 2.350 COAL.The 204s like some jump,because factory ammo was shooting mid 3s ,for groups out of my LRPV with the 2.250 COAL.If I seated to touch the lands,there wasn't enough bullet in the neck.