Just had an interesting incident at the range. Had the Chrono set up as per always when building loads. Started working up loads for my new RMR .300 Ultra Mag referencing the load data I still have from the Model 70 Win .300 Ultra I had for years before. I sold it to buy a .300 WSM (not my cup of tea). Anyways I buy a pound of Retumbo as this has always been my go to Ultra Mag powder. The label on the Retumbo states a max load of 100.5g/3300fps for a 180 grain bullet. I always ran 96.5 in my old rifle at around 3325 fps. So I started loading 180 Accubonds at 94g @ 3230; and started working up. At 96.5g I was at 3410.....hmmmmmm. Max says 100.5 (why was I only using 96.5 before).......fired one at 97.5g.....3510fps holy chit!!!!! Pull back now sticky bolt and no case comes with it. Case tapped out easily with a cleaning rod. No damage done; but wtf?? Go to Nosler load data and it states a max of 95g for Retumbo on their website for 175/180g bullets. I had checked my old data and the Retumbo bottle and figured I was good to go; hell not even close to max before. I can't imagine someone without a chrono just throwing the max on the bottle into a case (going off the 10% safety factor myth) and touching one off. Learned a lesson here and should have went with my instincts and reloading expierience rather than letting the label override it. I thought hitting the max 3300fps; 3.5grains before the max load was not right....it wasn't. Research and trust that Chrono.....96.5 is a MAX load in this rifle as it was in my last Ultra with 180 Accubonds and Retumbo; I will most likely look for the most Accurate load in the 94.5 - 95.5 range which will have me back in that 3300 fps range.
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