Re: 308 difficulty
Do I have this correct? You test loaded (in the chamber) some of your reloads. The first few were tight and then you ran into one that you had to slap the bolt back to get it out. This is the 5th reloading without FL resizing?
If the above is correct, it sounds like the body die is not getting the job done. The first one/two that you chambered, there may have been some lube in the chamber, and you were able to remove these. With each successive shell there was less lube until you had to force one out.
First of all, remove the bolt, and shine a flashlight into the chamber to make sure there is nothing (dirt, copper, brass shavings) that is stuck to the chamber wall. Next, take one of the suspect reloads and "paint" the lower part of the case with a magic marker/sharpy. Chamber, remove and look to see if there are marks on it. If not, paint other areas of the case until you find the problem. You may find you just need to FLR after the 4th firing of your loads and then you will be good for 4 minimum resize operations.
If the scuffmarks are on the bottom of the bullet (not cartridge case) this usually means there is a burr on the leading edge of the chamber and as you chamber a round it scrapes the base of the bullet. This will happen when chambering a round from the magazine, but will not happen if you just lay them in there. Another cause could be the chamber edge is causing the scuffmarks when you remove the loaded round, but this would be on the right side of the bullet (viewed from the rear). Regardless, if you feel this is the cause, easing the edge with some 600 grit wet or dry sandpaper is the solution.
Hope this helps.