Post by mortensen on Nov 12, 2008 21:01:35 GMT -5
Reloading Guidelines: Part 2
NOTE:
Reloading manuals recommend specific OAL (overall cartridge length) dimensions according to the industry standard (SAAMI spec.) These loads have been tested to be safe at that particular overall length, and they will always chamber in your firearm. Finding the exact 'optimum' requires a bit more information than reloading manuals provide. Finding the best OAL for your selected bullet will give you the ultimate potential in accuracy.
The way I look at it is that there isn't much choice when it comes to the seating depth of a bullet. In other words you have to take what the ogive of the bullet will give you when it makes contact with the 'lands' (grooves). Once you determine this you can back the bullet in 1/1000 or so which I do. Some benchrest shooters prefer their bullet to be right on the lands.
The main thing now is to determine your OAL and this can be accomplished a couple of different ways. I use the old fashion method that works for me and I double check this process 3 or 4 times to be exact.
Remember, the seating depth may be different on a .243 Savage as it would be on a .243 Remington. Manufacturers use slightly different tolerances in manufacturing regarding the chamber (throat).
As mentioned I use two different methods in determining the OAL. One method is to split my case in 3 cuts down to the base of the scoulder. (See below mentioned site, second diagram and the article will also tell how it's done). I place the bullet in the case about 1/8"", gently chamber the cartridge, close the bolt. By closing the bolt the bullet ogive will stop at the lands and move no further. I then. Remove the cartridge and this will give you your OAL. Another method which I prefer to use is to tape the bullet to a 2" dowel rod, gently slide it into the chamber until it stops at the lands. Run a long dowel rod down the barrel until it (gently) touches the bullet, mark the dowel rod (end of barrel). Remove the bullet, close the bolt and run the rod further down until it contacts the bolt face and mark the dowel rod and this will also give you your OAL.
There are tools and gauges available that will accomplish the very same thing. I simply prefer this method and can do it just as fast as any gauge will do it. Besides, I'm sort of in my own confort zone it doing it this way.
OAL
www.larrywillis.com/OAL.html
NOTE:
Reloading manuals recommend specific OAL (overall cartridge length) dimensions according to the industry standard (SAAMI spec.) These loads have been tested to be safe at that particular overall length, and they will always chamber in your firearm. Finding the exact 'optimum' requires a bit more information than reloading manuals provide. Finding the best OAL for your selected bullet will give you the ultimate potential in accuracy.
The way I look at it is that there isn't much choice when it comes to the seating depth of a bullet. In other words you have to take what the ogive of the bullet will give you when it makes contact with the 'lands' (grooves). Once you determine this you can back the bullet in 1/1000 or so which I do. Some benchrest shooters prefer their bullet to be right on the lands.
The main thing now is to determine your OAL and this can be accomplished a couple of different ways. I use the old fashion method that works for me and I double check this process 3 or 4 times to be exact.
Remember, the seating depth may be different on a .243 Savage as it would be on a .243 Remington. Manufacturers use slightly different tolerances in manufacturing regarding the chamber (throat).
As mentioned I use two different methods in determining the OAL. One method is to split my case in 3 cuts down to the base of the scoulder. (See below mentioned site, second diagram and the article will also tell how it's done). I place the bullet in the case about 1/8"", gently chamber the cartridge, close the bolt. By closing the bolt the bullet ogive will stop at the lands and move no further. I then. Remove the cartridge and this will give you your OAL. Another method which I prefer to use is to tape the bullet to a 2" dowel rod, gently slide it into the chamber until it stops at the lands. Run a long dowel rod down the barrel until it (gently) touches the bullet, mark the dowel rod (end of barrel). Remove the bullet, close the bolt and run the rod further down until it contacts the bolt face and mark the dowel rod and this will also give you your OAL.
There are tools and gauges available that will accomplish the very same thing. I simply prefer this method and can do it just as fast as any gauge will do it. Besides, I'm sort of in my own confort zone it doing it this way.
OAL
www.larrywillis.com/OAL.html