Originally Posted by gr8whyt
If you have any fired brass from this chamber that has not yet been resized, measure the neck diameter and add .001. This will tell you how much expansion you are getting from the .297 neck diameter of your loaded rounds. I looked at the SAAMI dimensions for the .260 Rem chamber. It's .298. so your right near there. You might not be getting enough expansion. Good luck
Some of the guys shoot rifles that are "Tight Necked" and do OK with careful reloading.
I consider a OD of .003 larger after firing to be minimum. On low pressure loads you can
get away with .002 (.001 on each side) With big cases that typically are high pressure
I want .004 (.002 each side) for safe high pressure velocity loads.
A simple way to verify if this is the problem is to pull the bullet on a couple of the custom
loads keeping the powder charge to replace after turning the necks down a couple of
Fire one and see if it makes a difference.
If it does you will know where the problem is and what you have o do.
J E CUSTOM