wondering on 309L/316L tig filler rod differences

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No big deal, but I mixed up some tig rods a while back after doing some non-critical exhaust welding and other stuff.  I had some 309L and 316L rods mixed up afterwards and I got to thinking: would it really be that detrimental for hobbyist exhaust type work if I used, say, a 316L rod thinking it was a 309L rod (and vice versa)?From the research that I found (Harris Link , Chase Alloys Link, Intern'l Moly Assoc. Link), it seems that (in harris rods anyways) on average 316L has more Moly (~3x) than 309L (some 309L not having any at all), and 309L has more chromium (about+5%).  Nickel content seems almost identical, on average 13% for 309L and 12.5% for 316L.From what I gather, it seems that 316L could possibly work alright where I would need 309L because of the similar Ni and Cr content, but not the other way around since 309L likely has little to no Molybdenum that would be required in 316L-to-316L welds.  Am I somewhat correct? 1st on WeldingWeb to have a scrolling sig! HTP Invertig 400HTP Invertig 221HTP ProPulse 300HTP ProPulse 200 x2HTP ProPulse 220MTSHTP Inverarc 200TLP HTP Microcut 875SC
Reply:That is how I approach the two. On occasion I can't get 309 to not crack. 316L for some reason solves the cracking problem. However I would never use 309 on 316 weldments.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Awesome, thanks. 1st on WeldingWeb to have a scrolling sig! HTP Invertig 400HTP Invertig 221HTP ProPulse 300HTP ProPulse 200 x2HTP ProPulse 220MTSHTP Inverarc 200TLP HTP Microcut 875SC