ANOTHER BIG 239 FANBOY HERE.
Mine is a stainless 40 cal with the Sig short reset trigger & action enhancement package. With 155gr Hornady XTP's over 6 gr's of unique I HAVE shot A better (LUCKY) group (6 shots @ 30' offhand 0.86") than with the full size 226 or 220, maybe just a one time thing??? Anyway my thoughts are 1: what's the big advantage to going to 357 Sig? 2: even if you COULD get your 40 239 to fire 9mms, the 40 cal (in stainless) FEELS much bigger/heavier than the 239 9mm (standard alloy), to me. 3: While I have the SRT feature and the actual short trigger on my 226 & 220 they are thinner (mims???) & appear more fragile than the original trigger & why I left the original trigger on the 239 alone. SO, for the $ I think I would rather just get another 239 (non stainless) in 9mm, save some wt???, & have 2 guns. What say you? EDIT, let me be the first to correct myself, The 9mm & 40 cal ARE the same size. I'm accustomed to the wt of the stainless 40 cal & the standard 9mm just felt much lighter/slimmer to me. Another + for the 239 is you can hit the same primer a second time without racking the slide. Sorry for any confusion.