Regardless of his twist and barrel length, start loads are listed in many reloading manuals and even websites i.e. Hodgdon Data Site. Go to one of them, find the bullet weight you want, the powder you want or have and start there working up, as you are supposed too do, for safe and sane reloading.
Don't anyone use manuals and data sites anymore ?
Bill K,
I couldn't agree with you more. Many chambers in the same cartridge are different, i.e. throating, dimensions. The manuals tell you
, "
START LOW AND WORK UP!" for a reason. As I just noted, my .22-250 starts seeing pressure almost a grain before max. My .257 Roberts doesn't show pressure until a grain over max.
When people come along and ask, "What's your load?", like they want to start there. They are breaking the number one safety rule in reloading. Load for your weapon only. Unless you want to go commercial and get the ATF ticket to reload to do that, I wouldn't. It means you have to get a bunch of liability insurance. And those who condone that, or even push it are not thinking safety.
Another issue is old powders vs. new powders. The ones that were preserved correctly. If any of you have old Hodgdon single base powders, compare them to the new 'Extreme' powders. Extreme powders were reduced in kernel size and coated with a burn retardant. They are not the same powder. Powder companies named them by the old numbers to avoid confusion, but in reality it caused confusion. While the powder does give a wider pressure ceiling to work under, it is still lower. We used to load 41 gr. of old H4895 or IMR4895. We can only 40 gr. now. And, the pressure curve goes up fast. Most new powders today are different than the old ones.
Once you've burned through the retardant, it's like having a case full of really fast powder in there. Stay close to the manuals. If you work up above them, work up in small increments. Like .1 or .2 gr. instead of .5 gr.
And find a published starting point to work up from, not what somebody told you on the internet.