Dave Brown said:
6BRinNZ said:
Dave - have a look at Eik Cortinas youtube channel on this subject.
https://www.youtube.com/watch?v=U9XpnpgJd0A
Yes, Erik has been helpful however don't think he shoots 308 but maybe it doesn't matter.
The process in the video has nothing to do with calibre. I actually can't figure out what you are trying to achieve...on the one hand you are talking about tight necks and your gunsmith having the equipment to alter the throat but in another post you state you are ordering the reamer.
If it is just the bullet seating depth then repeat what Erik has suggested but with the bullets and brass that you want to use...there is no rule of thumb for seating depth other than stay to away from the neck shoulder junction. In the video Erik states to allow .030 for this...then allow another .020 - .030 so you can run seating depth tests with jump. In the .308 this measurement should also allow plenty of neck to experiment with jam if you choose.
If you are restricted by mag length then its a different story - in that the longest length you have is mag length so you can only be shorter than that.