I am loading my 1st rounds I have a RCBS supreme kit and other items to get started with so I am loading for my 243 to start I figure that will be a cheaper round to start on. so my question is this I checked the gun for seating depth and came up with 2.765 and with a recommended set back of .015-.03 I will be longer than the 2.71 SAAMI overall case length. Is it OK to seat it to 2.750-2.735 or do I have to go down to 2.71. Thanks for any help I get MARK. Also i am loading 95gr ballistic tips on 39.5 grains of 4350
First time loader question
- Thread starter mkcj
- Start date
rick smith
Handloader
- Apr 6, 2005
- 1,249
- 0
Function through the magazine, not be jammed into the lands and have enough bullet in the case neck to hold it.Rick.
Desert Fox
Handloader
- Aug 14, 2006
- 1,965
- 5
Welcome to the forum mkcj. Don't get confuse between the case length and the Cartridge Overall Length. The 2.71 is the maximum case length for the 243. If 2.765" is the maximum seating depth where the bullet is touching the land, then your starting seating depth would be 2.755. That will give you .010" off the land as a starting point. Make sure though, as Rick Smith suggested, that this seating will fit in your rifle magazine.
DrMike
Ballistician
- Nov 8, 2006
- 38,190
- 8,289
Mark,
Great question. The rule of thumb is that you want to have at least one diameter of neck to ensure sufficient tension on the bullet. If you are loading the .243, you want the bullet seated so that at least .243 inches of the jacket are in contact with the case. This means that you can load far longer than SAAMI standards. The standards provide measurements that permit a measure of uniformity across various platforms. Rick is correct to load so the round fits your magazine and does not jam the bullet into the lands. Do be careful not to confuse overall length (cartridge overall length (COAL)) and case trim length. Case trim length is somewhat more critical, whereas overall length can (and does) vary depending on the depth of your throat.
What rifle do you have? Winchesters tend to have longer magazines. Remingtons and Brownings tend to have shorter magazines. Savages and Rugers can fall either way.
Consequently, are you loading A4350, IMR4350 or H4350?
Addendum: I just now noticed Desert Fox's answer. Listen to his explanation. He is spot on.
Great question. The rule of thumb is that you want to have at least one diameter of neck to ensure sufficient tension on the bullet. If you are loading the .243, you want the bullet seated so that at least .243 inches of the jacket are in contact with the case. This means that you can load far longer than SAAMI standards. The standards provide measurements that permit a measure of uniformity across various platforms. Rick is correct to load so the round fits your magazine and does not jam the bullet into the lands. Do be careful not to confuse overall length (cartridge overall length (COAL)) and case trim length. Case trim length is somewhat more critical, whereas overall length can (and does) vary depending on the depth of your throat.
What rifle do you have? Winchesters tend to have longer magazines. Remingtons and Brownings tend to have shorter magazines. Savages and Rugers can fall either way.
Consequently, are you loading A4350, IMR4350 or H4350?
Addendum: I just now noticed Desert Fox's answer. Listen to his explanation. He is spot on.
- Thread starter
- #5
- Nov 4, 2004
- 27,124
- 13,624
mkcj
Welcome to the forum, glad you are here.
Rick Smith and Desert Fox have given you great advice.
Give us a range report with your first reloads. :grin:
JD338
Welcome to the forum, glad you are here.
Rick Smith and Desert Fox have given you great advice.
Give us a range report with your first reloads. :grin:
JD338
wisconsinteacher
Handloader
- Dec 2, 2010
- 1,984
- 302
Good luck and welcome. The guys on this site are wonderful and have helped me so much. Don't be afraid to ask them questions.
