I am not new to turning necks and reloading for the 6PPC. I have always just loaded to what is in bullet manufacturers reload data books. Wanting to pursue more accuracy, I have been reading more and more about the bench rest shooters loading with H322, N133, and benchmark powder to what are loads that I am not able find in load data books, a lot of talk in clicks of powder and not much talk of grains of powder. Is there a safe path to follow when experimenting with loads that are not in the books? Maybe I am misunderstanding or am not up to date on the acronyms used within the bench rest crowd. I am not sure as to what to ask and when to ask, so I guess i will just satart with something. How do the benchrest shooters know when they are reaching a dangerous point in the amount of powder they are loading in the cases? Example: The sierra load data book lists their 70 grain BTHP calls for 24.4 grains and 25.4 grains of N133, but I feel as if the bench rest shooters are shooting hotter loads than these listed. My rifle is a Sako AI or L461 6PPC with an aftermarket heavy tight neck barrel with a neck diameter of .262".
The C.O.L. to ogive is 1.702" using the Sierra 70 grain hpbt. I am still just scratching the surface on where my lands are in relation to my bullet, how many .000" off the lands my bullets are, but I am still not sure how to tell where this plays in my group size. Does ".000" off the lands" close group size form .375" to .250" or is it going to shrink it .365". So while I am still just getting the feel for things, I would like to have a better understanding on how far to go and when to say no as far as loading with loads not listed in the load data books.
The C.O.L. to ogive is 1.702" using the Sierra 70 grain hpbt. I am still just scratching the surface on where my lands are in relation to my bullet, how many .000" off the lands my bullets are, but I am still not sure how to tell where this plays in my group size. Does ".000" off the lands" close group size form .375" to .250" or is it going to shrink it .365". So while I am still just getting the feel for things, I would like to have a better understanding on how far to go and when to say no as far as loading with loads not listed in the load data books.