Those Grooves in the saddles were an upgrade introduced in 2008, in addition to a higher mass bridge. The grooves were there to fine-tune the string spacing. The drawback is that the narrow groove "pinches" or "crimps" the string at its' most stressed point which is the break over the saddle. A lighter string/thinner core will be more likely to fail especially with aggressive playing styles. Sanding or filing the saddle is normally a good idea, but ONLY on a single-groove saddle. The best solution would be to replace the saddle with a good-quality retro-fit saddle with a SINGLE groove. Your are supposedly milled brass, so a brass replacement wold be closest to the sound. You can, however, replace ALL the saddles with Steel, Brass or Graph-tec. Go onto Stewart MacDonald and see what's available. Saddles are NOT expensive, so don't try to save money by going cheap. Get ones that are solid-milled (not cast). In the interim, you can use a lighter attack and turn up the gain a bit. If you have the option of stringing through the top, I would try that first. There is a lot less pressure stringing it that way. Also, if it does have this option, you can string just the G and D thru the top and the lower strings through the body. You may get a different response and you may prefer it!
