I have X dies for both .223 and my .308. Sorry this is kinds of long but may give you something to think about... I am shooting a Savage 10BA-LE (.308) and keep having problems with stuck cases in the chamber. I am not shooting a hot load (43.4 gr Varget w 175 SMK) but still see pressure signs sometimes. I am loading 0.010"-0.012" short of the lands. I have been using IMI Match brass that is on it's third firing and is giving me all kinds of problems with almost every case sticking now. I recently prepped 100 once fired BHA match cases and shot them with the same load. These worked fine in my rifle but I had to add 2-3 clicks to my dope (.2-.3 mils) beyond 400-500 yards. I checked the case volumes of 6 kinds of brass (weigh empty/ fill with water and weigh) and found the BHA has the largest case volume. The IMI Match is similar to LC87, LC96, FC nato, PMC, CBC. Only Winchester was similar to the BHA in volume.
One of my brothers shooting buddies has a friend with a 110BA-LE (.338 Lapua). He was having exactly the same issue. He tried different brass/loads, but after a few firings/FL sizings the same thing would happen. He talked with Savage and they replaced his barrel and it was OK for a short period then it came back. Then he bought some Lapua brass and after 3 or 4 sizings it was also sticking. He spoke with "master reloader" at Lapua and this guy thinks it is the way the brass is being sized. It is being forced back and apparently causing a tiny "ripple" inside the case. After a couple of firings this turns into a weak spot/ring inside the case. When the round is fired this weak ring balloons out causing the case to stick in the chamber. I am telling this third hand (swapped emails with my brothers buddy) but have not been able to talk to the owner yet. I believe he is using RCBS match dies.
Ultimately while I have read mostly neutral and many positive things about the X-dies, I am concerned about them and thinking of getting a Redding competition dies set to replace them... Right now I have 500 pieces of IMI match brass with 2-3 firings on it and I don't want to put it in my gun... However I am unable to find any new brass for sale so I'm kind of stuck (no pun intended). I guess I would be cautions about using the X dies for a high power cartridge...
