Hello everyone. I'm new to TFL and this is my first registered sight for posting some questions. I've just begun reloading and have been trying to read online and read a few books. Specifically Horady, Nosler and a small handbook for the 9mm. I've had some troubles finding a few answers to my questions. My primary goal is to reach accurate loads. I'm not trying to hit max velocities unless it yields higher accuracy. Main guns I'm playing with at the time is the 9mm Springfield XDM and Hi-point carbine 9mm.
I'm want to know with a semi auto how to determine the best oal length. With a rifle my understanding is to find the max and back it off so far .015 to .030, thus giving you a slight jump to the rifling. I feel like with a semi auto that you are increasing the jump to the rifling. There is a huge difference in the max oal between the 2 guns i'm playing with. I've also read that decreasing the oal in the 9mm can and will increase pressure dramatically. Again I would like to go for accuracy and may go outside of the oal spec some, which means I would only load bullets for each gun and not try and mix them if that makes sense.
Another question is high pressure indications. Specifically to the 9mm cartridge. All the pressure indications that I find seem more for bolt or semi auto rifle rounds. Like flattened primers, rings, etc. Is there anything more specific to 9mm semi auto cases to look for that doesn't involve special equipment and is visible to the naked eye? I worked up some loads with the carbine untill getting to a max load according to the books and feel like all the primers looked fine. I felt like the accuracy was terrible though. Of coarse I'm talking about a hi point though...