Anyone who has read my posts on reloading know I have been a proponent of coated bullets; particularly the Hi Tech Coating offered by Bayou Bullets and SNS Casting. I have always had superior results from both manufactures. Loadings have been, 9mm, 38 special and 45 acp using Bullseye, Clays, Red Dot and Titegroup powders.
Until now.
I recently purchased an M&P40 Full size and ordered up 500 - 180 grain .401 bullets from SNS casting. My plan was to use a light 40 S&W load in IDPA SSP until I could acquire a 9mm conversion barrel for my new toy. My first loading was 3.8 grains of Titegroup (.2 grain below the book starting charge). During my first session I chronographed this load at 903 FPS for a power factor of 162. A tad hotter than I wanted, but as a starting load I would take it. Problem being that it is extremely smoky and severely leads the 2nd half of the barrel. After cleaning the barrel (What a PITA) I tried again at this month IDPA match. Again smoky and heavily leaded the barrel, this time to the point that the 2nd half of the barrel looked like a smooth bore after only 90 rounds. The only time I have seen a barrel that bad was when someone shot soft lead reloads out of a Glock. By the time I got to the man on man Dueling tree match I lost in the third round to the eventual winner. In that round I couldn’t hit ONE of the 6 inch plates at 10 yards. After three days of effort and I am still removing lead from the barrel. A Lewis Lead Remover for .40 in on its way from Brownells.
I have previously used 3.8 of Titegroup under 160 Grain 38 special and 230 grain 45 acp SNS Casting bullets with good results and no issues.
I have inspected the barrel and see no issues that would lead me to believe it was a barrel issue.
I don’t know maybe SNS got a bad batch of coating? Maybe the dynamics of the cylinder gap on the revolver and the larger case capacity & bullet base on the 45 make the difference.
I now have in house 140 grain Bayou bullets to try, I’ll let you know after Saturday how they make out.