Actually, I had never heard of the bulge Buster Kit until just a few days ago. I don't think I need it as the carbide sizing dies do the job just fine for the calibers I reload. If I load hot, I inspect the cases carefully and if they are bulged too much, I toss them. Most of my brass is collected at my range from shooters who do not reload and the brass is one time shot, so usually the brass is not bulged to any extreme.
I use the carbide sizing die also and it does fine as far as it goes,the problem is mostly with cartridges shot from Glocks.There may be others that have the same problem and that being that the case head is unsupported in the area by the feed ramp.In high pressure rounds this unsupported case will bulge.Your carbide sizing die will not get this bulge out,it doesn't go down far enough on the case.the only way to get it out is to run the case completely through a sizing die,in this case the one from the Lee Factory Crimp Die is used in conjunction with the Bulge Buster.I was kind of skeptical about this until we had a case head completely blow off a 357 Sig round.There was no other reason it would do this except the case was bulged.I checked with a friend of mine that is a commercial reloader and he confirmed this.He runs all his cases through a Bulge Buster.The gun wasn't hurt,nor anyone,but it's not something I want to experience again!
Well I must not have much Glock brass..But I will look more closely at my brass after I shoot. Since the majority of my loadings are .45ACP, and pressure is not extremely high, I never really worried about it. But I also load .40S&W too..so I will watch closer on those too. If I see a problem with any of these two calibers, I will surely try out the bulge buster kit. My set up is Lee anyway.