Brand new to crossbows, bought a Excaliber Micro 315 kit from an archery shop last spring. Great experience, they let me cock and shoot several until I was comfortable. I didn't buy broadheads at the time, because I had a Cabela gift card to use up. Anyway, I must have asked about them when I bought the bow because I wrote 100 gr on the back of the manual. Anyway I bought 100gr, but never opened the pack as I was practicing with the field points all summer. I was planning to shoot the broadheads tommarrow but the kit says I have 150 gr field points. Should I get heavier broadheads, try these, or do broadheads fly differantly ? I'm a real beginner so any help would be appreciated .