PDI w/hold bucking questions

Well I plan on purchasing to see how well it works in my dmr setup. I am chosing it over a 2gx bucking because it has thicker ridges(not sure what to call them) inside which provide more stability. My question is will it require less of the bucking to be pressed into the barrel compared to a standard setup? Becuase i want to run .4g washed at around 430fps and its borderlining jamming. Also a mini review/or opinion on the bucking would be nice and any input is welcome.