Fulton's spring guides sure look like they are patterened after Brookfield's, at least in theory. I have a Brookfield in one of my 14's and Fulton's in the others. As far as greasing goes, right or wrong I always grease mine. I don't like to see 2 pieces of metal rubbing against each other without lubrication. We're not talking combat here. I don't think you would want a Brookfield in a combat situation, it could hold onto too much dirt. I think the military spring guides with the holes in them were the best for shedding dirt. Please correct me if I am wrong.