These are s type bushing dies. The use of bushings in your sizing dies "neck or fl" allow you to controll neck tension which is VERY important to accuracy at distance. .002-.0025 neck tension is optimal....NEVER over .003. Different Bushings allow you to have exactly the right tension for different brands of brass. A standardsizing die is going to reduce the necks waaaay down to make sure whatever kinda brass you use it will hold tension on the bullet.....allbeit too much negatively effecting accuracy.
So if you got a reg set of dies load what ever brass and bullet your gonna use in them. Then measure the OD of necks of loaded rounds on my 6.5 comp gun its .291 neck loaded,i use a 290 bushing its ti nitride coated so that gives me a lil extra iso i end up at .2885-.289 the .0005 variation is because I DO NOT TURN NECKS it is unnecessary.
Its really simple once you see it and understand it, but i remember it seemed complicated when i was learnin it too.
These are the best dies you can own. The only reason im selling is im focusing on my competition rig and less on long range killing gun.
Hope this clears it up a bit . If ya got anymore questions ..shoot
$260 worth of dies for $180 shipped......surely you can swing some bushings.
They are used by previous owner,i havent loaded any with them because i decided to stick with my comp gun chambered in 260. I have however loaded literally thousands of rounds on a set for my 260 so your not gonna wear em out.