bronco93 wrote:So been reading up about how to get more accuracy from reloads . So correct me if I'm wrong but to find out the specific OAL you would first just seat a bullet in the case enough to hold it then mark the bullet- I used a lighter to soot it up. Then gently close the bolt and open it up and whetever the soot has rubbed off that is the specific OAL for your rifle. I have tried it on my Remington 700 243 and averaged 2.565 inches(Im using sierra 75gn SP). What do I do next? Do I seat the bullets deeper or just try some reloads working my way up .5 gn of powder. Hope that all makes sense.
Cheers
I prefer to put a rod down the bore against the bolt face and mark it with a piece of tape at the muzzle. Then drop a bullet into the throat and hold it in place, drop the rod down the bore against the bullet, mark it again. Measure between the two pieces of tape.
Once you've determined that length for that specific type of bullet, I would start with seating it 20-thou shorter. Then either shoot groups at different charges or shoot a ladder to find the elevation node. When you decide which load you want, start playing with seating depth working backwards from the length you measured. None of this matters though if you want to feed from a magazine that's too short for ammunition loaded to the lands.
What you are measuring is how far the bullet jumps before it hits the rifling. Measuring to the point of the bullet though is rarely accurate enough for this to work well. You need to measure the length of the cartridge from the base to the point along the ogive where the bullet meets the rifling, or "bore diameter", generally about .008" under bullet diameter - a .308 would ideally be measured to the point at which the bullet is .300" in diameter.