Back in the early '90's, because of a break in at my house, my usual silhouette pistol, 10''-.44-DW was stolen. All I had at the time for revolver class, was a 10''-.357-DW. Which incidentally had a 1-14 twist. I cast a 210gr LBT bullet and put 12.5grs. of 296 over a Fed.200 primer. In the following years I shot myself into International class with that pistol and load.(never shot a 40, but plenty of 38's and 39's) With the weight of the bullet there was enough energy down at 200m to knock over rams.(These by the way, are full size rams, weight around 55lbs.) Not sure, but I do belive you'll lose to much energy with that light of a bullet.(158gr.) If you can, get either 180's or 200gr bullets, for better retention of energy.(200gr prefered) With the extra barrel lenght, you shouldn't have a problem-gypsyman