Does anyone know how to safely increase the poundage of a 70lb bow to 80lbs? I was told about placing some material under the limbs in the pocket to add more poundage, but would like more input.

The only safe way is to order new limbs, their rated only for the pounds on the sticker. But if you wanna add a few pounds but i would'nt recomend 10, just twist up the buzz cable or replace it with about a 1/8 inch shorter one. Be careful....those are some nasty splinters...lol

See you local "Pro Shop". On some bow designs this is possible. I don't recommend twisting the buss cable(s) or changing the design length too much unless you know your cam timing characteristics.

I agree with Len. There are ways such as shimming and pre-stressing the limbs, but most limbs have a specific range in which they perform to their optimum potential, and going outside of that range can DROP performance of the bow, or in some cases be very dangerous. Check with a reputable shop before trying anything, the $150 for new limbs may be cheaper than emergency room bills should it blow up on you! Good shooting, Pinwheel 12