I run 303 slower than 304 with sandvik tools, its more of a personal preference for me. the reason is 303 is really abrasive and tends to wear the tip of the insert down faster than 304 does, yes 304 is tougher to cut but it runs smoother than 303 especially on cut off and facing tools.
one machine (omni turn )we run 303 in runs only oil and that machine we can run a cut off blade for 1 year(micro 100 cut off blades) on 303 and not worry about wearing it out. it runs every day on 3/16 dia to 5/8 dia 303 stock.
it runs a .025-.050 chamfer depending on part dia. and cut off .
used to cut tons of 303 in 2" and up( in bigger lathes) and I always cut down the SF on 303 vs 304 for the same reason.
shane I think i know what secos wnmg your talking about those are fantastic inserts, they last longer then the sanviks for 9310 gear steel and 1045 too. I use them for rough cause I get alot more parts per inserts.
I got like 1 box left.
BTW were do you get the seco the place I used to get them locally closed many years ago.and I havent looked for a new place yet
the main problem we have with inserts is jumping from sqaure shaft to round bar to hex, etc, in stainless steel. the 1125 grade sandviks take the abuse of the interrupted cut and keeps on chugging.
we do use the cheaper mitsubishi inserts when we machine 1018, 1045, and 4140, as those seem to handle it just fine.
any insert works for delryn, but we have some sharp edge prep non coated inserts for uhmw to help from stringing up.
for a interupted cut wnmg 432 I use the valenite wnmg-432-lm-sv325
have very good life in in hex and casting along with heavy hot roll scaling and other interupted cuts.
Thanks for the link