I don't fuel my 303's with full power loads as they have a past that to me is unknown but is relation to my 6.5 x 284 which is a totally different animal it needs to be at the top end of the pressure scale to be accurate that I have no probs with as I brought it new.
My 46gns of AR 2209 (H414, 4350 or IMR 4350 for you chaps) is still 2 grains under Max as in Nick Harvey's 9th Ed.
I have said to people when training them in safety - You may have done the same job a 1000 times and then one day something will be that little bit different which you wont pick up on because you have done it all before with no problems and that my friend is when you will get bitten.
My last industry I played in was power generation where we had 110 tonnes of steel doing 3,000RPM driven by 300 degrees celcius of steam at 20 atmospheres pressure and cooled the generator end of the turbine with Hydrogen plus each boiler 8 of contains 90 tonnes of steam which expands at 1500 times by volume with all the other goodies that go with it like 99% pure hydrochloric & sulphuric acid on site.
Yes siree you can do a thing 1000's of time then one day you will miss something through familiarity and suffer the consequences usually in the above it is fatal which they did have a fatal at the site before I was there.