Oprod length can be confusing - Adams Arms P Series Micro Adjustable Block Piston Kit

This is a great kit. The lightened BCG and spring setups are specifically for the lower pressure 300 blackout. My barrel was pre dimpled for a gas block and, like others found myself with a fully collapsed BCG and 0 distance gap with the oprod. I should shave .010 off the end of the rod or gap the block by .025 but that seems like a work around when i know my gas block is exactly over the port. The gap is allegedly to allow for when things het hot and metal swells a bit.