Tonight I was loading up some .300 win mag ammo to try out tomorrow. Brass was once fired and full length sized Lapua. First lot were Barnes MRX and everything went to plan, as usual. I had the rifle on the bench to obtain and double check overall length on each load. Then some Lapua Scenars. I loaded 5 up and while I was running them through the rifle to see if the bullets were engraving, one round stuck. It was a bit hard to close but I put it down to the bullet still seated too far out. The bolt came back out without the cartridge and I had to tap it out with a cleaning rod. Confused, I decided to try it again. This time it was tough to close the bolt, but I figured I see if it would grab the round and extract it. It stuck again. I put that case aside and continued to check the others. A few trials later, another round stuck, same thing. I grabbed my calipers and started checking for anything out of spec. Nothing was out. It seemed that maybe the shoulder on these cases was contacting the chamber more than it should but it's hard to tell. Still not satisfied I ran a boresnake through the chamber and barrel in csae there was anything in there and tried the sticky cases again. They stuck, and had to be tapped back out. I measured them again, nothing out of the ordinary. After that I got called away from the reloading shed, I'll probably just pull the bullets and re-size the cases, but it was truly strange. Any ideas?