i recently had two separate case bolts snap on me on two different cases. In one case I was really pushing hard on the bolt and in the other case I hardly applied pressure and it snapped on me. Also it didnt matter what the other case bolts felt like...on case all the bolts were really a struggle and in the other case all the bolts gave way with almost no effort except for the one that snapped.
The only "noobish" advice I can offer is that when a bolt is giving me a little fight I take a rubber mallet and tap the socket handle with continous medium taps as apposed to just pulling on the bolt as hard as I can. In both cases where my bolts snapped I was tuggin on the bolt hard and I think the tapping method allows the bolt to relax for a split second or two and this makes it less likely to twist off...or atleast thats what worked for me.
Good luck! I just spent $120 getting my case drilled and tapped!