5.56 can be a real bugger. Tite crimp and small flash holes are common on non - US surplus. I gave away a large lot of Austrian 5.56 that had extra small flash holes. I worked over a small RCBS primer punch and got them to work but it was such a PITA and there is so much brass out there that I gave up and sold it along with the punch to a guy that was looking for cheap brass. Shame too, it was really nice brass and shot so well on the first go round (loaded surplus) If the flash hole is not the issue, I recommend the Lee deprimer die. I almost hate to admit this but the Lee deprimer die is superior to the RCBS. Although the Lyman die is good to. I am not familiar with the Hornaday but they make some good stuff also. When I first started out reloading (30-06) I used the Wilson system and it works but is slow. I have the same set up for 5.56 but use it seldom(onesies and twosies) like I said it is slow. As I said before, there is so much brass out there for the 5.56 that unless you got thousands of empties for free maybe you should just call it a lose - lose deal and buy some processed brass. The reloading hobby is supposed to be fun and depriming and processing military cases is just about the worst part of it, no sense in making it any worse that it is! Sorry I could not be be more helpful.