You stated that you can't get your broadheads to fly well, and that the ones you are using are britle...I will not try and be a archery pro here, and only offer this advice if you're looking for a new broadhead...Try VPA's Terminators. They are machined out of a solid piece of steel, so they are not cast or welded...making them extremely tough...I shoot the 100 grn heads out of my compound (and the 160 glue on's from my recurve) and I have found the 100 grain heads shoot to vertually the same point at my field points...but that is in my bow, my set up, and my shooting style...again, not to "armchair" you to death...just to answer your question, I highly recomment VPA's Terminator series heads...you can find them on the web, and they are American made (just another bonus).
G-C-R (Jason)