The biggest difference between Madbull and lonex buckings is that the lonex buckings are quite thick and may not easily fit into all setups. Make sure to test feeding by assembling your barrel and hopup, then manually dropping a BB into the chamber, then gently tapping the BB so that it drops into the barrel. If it takes force to make it go through you may run into jamming problems. If a gentle tap is all it takes you should be good.
As far as hardness goes, You may wish to use a harder bucking for higher fps setups. You might want to consider getting your DMR closer to 400fps to more appropriately match your bucking hardness
