Basically, it involves machining two precisely matching mirrored solid pieces of steel with two holes drilled exactly in line with the two holes on each of the mount ears that the limbs are attached to. Then replacing the two machine bolts with ones that are the correct length to pass through the two pieces of steel (blocks that fit perfectly in the space that the limbs are presently attached to) and secured by the two bolts, on each limb bracket (ear). I want to engineer a way of designing a new bracket that is sort of the reverse of the one on the crossbow, complete with the ability to swivel in. The idea is to move the limbs forward approximately two inches forward thereby making the power stroke two inches longer, and increasing the speed of a launched bolt.
Using two solid blocks would work IF they could be somehow attached both by the bolts and to the front of the bracket too.
I believe a one inch thick steel block will work without the frontal attachment though. This would add one inch to the present power stroke.
Keep in mind that the curved area at the outer side of the block would have to match the curved area on the present bracket to a "T".
I have not actually done this yet, but have pretty much worked it out on paper.
That is all I have at this time.