looking for someone who could machine and re-work a benelli super black eagle from 12 ga 3.5" to 10 gauge 3.5".there are only 3mm of difference i think. the 12 gauge is 14,000 psi . the 10 hga 3.5" is 11,000 psi. the rim diameter is very slight bigger. to the naked eye you would say there the same.I have a h&r 10 gauge.I noticed the barrel is thinner than a 12 ga pump gun i have . same diameter barrel at chamber but has way less taper.