Ok I'm new to the hand loading arena. I thought that you could use what ever powder you have as long as you dont put too much in the case. I know now that powder goes with projectile weight. I have yet to load my first round because finding components is a huge pain. I did get a Lee loader for my "Margaret". I have posted about her before. Shes a .308 with a 16.5 inch barrel. I just want to concoct a load that goes with her. Do these kinda posts are helpful. Thank you guys.
This is kinda true within a range for each cartridge, but in general you have to match the burn rate of the powder to the cartridge and bullet you are shooting. Sweeping with a very broad brush, heavier bullets within a cartridge tend to do better with a slower burn rate powder, whereas lighter bullets tend to do better with a faster powder (again, within a range for each cartridge), though often you can find several powders that will work well for any bullet weight you'll load in a given cartridge. Also, for a given case/cartridge family, a smaller bore diameter will use slower powders than larger bore diameters. So, for example, 243 uses 4350 quite well although 308 prefers somewhat faster powders, even though their cases are essentially the same. You can see the same thing comparing 30-06 to 25-06 (generally slower powder than 30-06) and to 35 whelen (generally faster powder than 30-06). Also, recommended powder charges for bottleneck rifle cartridges tend to fill the case between roughly 90%-100%. These are not hard-and-fast rules, and there is a lot of overlap within cartridges across bullet weights and across cartridges. But these are general guideposts I have observed.
I highly recommend you stick to published load data starting out. I'm one of those old fashioned guys who prefers to have a manual with published data specific to the exact bullet-powder combination I'm shooting. That's not strictly necessary, and I don't always have data that matches my exact bullet and powder together when I load, but it's good advice starting out. Until you get a feel for what you're doing and what you can alter and when, stick to the recipes (including COAL, for now) in the manuals. If you don't have a reloading manual, get one and read it. Start at published minimum charge and work up slowly.
I haven't done a ton of loading for a 308, but sticking to the powders
@GooseGestapo mentioned is the easy button. I have used Varget, 4064, and 4895 with good results. As
@243winxb mentioned, Nosler lists IMR 4350 as an accpetable powder with 165 grain bullets, but all loads will be compressed. Personally, I probably wouldn't fiddle with that, especially not for my first foray into reloading. Availability of powder and components can vary by region, but if you are patient and pay attention you should be able to find something suitable (at least until things get crazy with the election later next year). Or, you can get impatient and pay hazmat to ship in whatever you want from one of the online retailers. Midsouth has Varget and BL-C(2) in stock right now, for example.
Good luck and be safe.
