Originally Posted by RoughCut
Great info guys, thanks. another quick question I have is... I see different load data all over the web and everyone has a different COAL. How do I know what my effective max and min length is? are these just trial by error lengths? I dont' understand how some loads are very similar but have different cartridge lengths. Does anybody have any thoughts on this or a reference to how length effects accuracy, etc...
There are a few different tools available to aid in seating depths and adjustment of same. The Hornady/Stoney Point mentioned above is one, Sinclair also makes one as does RCBS (the precision mic). I've only personally used the Sinclair and RCBS ones.
Hopefully you have a set of dial calipers. They are a necessary tool of the reloading trade.
Generally speaking, for hunting; you'll want to keep your COAL at a point that your ammo still feeds in the magazine. You can seat the bullets out further if you want to shoot the rifle as a single shot.
Start your load development with the longest round you intend to use, because pressures usually go up when the bullets are seated out close to the rifleing.
The seating depth is a preference thing, and each rifle/cartridge/bullet has it's own preference of where it shoots best.
The OAL listed in the books is not an absolute number, meaning it is only a guideline. Your rifle may shoot best with the bullets seated out .050" further or .020" deeper......anybodys guess. Simple trial and error and good record keeping/testing principles will tell you what your gun likes.
Just be careful of seating them out so far that they stick in the rifling when you try to unload a chambered round. This can leave powder all over in your action and ruin your day for sure. Also remember that changing the seating depth can change the chamber pressures, and proceed with caution.