February 14, 2005, 04:03 PM | #1 |
Senior Member
Join Date: December 9, 2004
Location: Dog Creek, CA
Posts: 457
|
COL to long?
I just reloaded my first 25-06 pratice rounds for my Remington BDL. My Nosler as well as Speer manuals say the COL should be 3.250". When I checked my bullet seating depth for this rifle I found it to be 3.223". I measured a factory round and it was 3.15".
On all my other rifles that I've reloaded for, I found my individual rifle seating depths to always be more than the published COL. What gives, has anyone come across this before? I ended up seating my bullets to 3.193". Bill
__________________
Retired Air Force 8th TFW The Wolfpack |
February 14, 2005, 07:34 PM | #2 |
Senior Member
Join Date: July 14, 2001
Location: State of Confusion
Posts: 2,106
|
COL length
Bill K--The COL of a manufactured cartridge has to be short enough to fit into the shortest chamber any manufacturer might make to chamber that round. Therefore it is 'way short for most chambers.
The actual COL you use might be limited by what will fit through the box magazine of your rifle, but barring that, it is limited by the depth of the throat of your rifle's bore. One normally seats the bullets to position them a few thousandths off the lands as this usually gives the best accuracy. Seating to touch the lands will usually result in a pressure spike when the round is fired so that is to be avoided. Exactly how much "jump" to use when seating your bullets off the lands varies with each gun, and is determined by experimentation once you have developed a load that is otherwise dependably accurate. Seating the bullets thus, it is very usual to have a COL which is over the published length. As long as it is good for the gun in which the round is to be fired there is no problem with doing this. Of course, you need to re-establish the proper COL to use with each new bullet you load, because the shape of the nose differs from one bullet to the next type, so the proper COL will vary accordingly. If that seems putzy, it is, but it's necessary to do for best accuracy, and to avoid the bullet touching the lands, or (very frustrating) refusing to chamber just as the largest buck you ever saw steps into your field of fire.
__________________
God Bless America --Smokey Joe Last edited by Smokey Joe; February 14, 2005 at 07:49 PM. Reason: Had another thought |
February 14, 2005, 07:41 PM | #3 |
Senior Member
Join Date: December 9, 2004
Location: Dog Creek, CA
Posts: 457
|
You mentioned the shortest chamber the manufacture offers. I agree, what I mean is the throat of my rifle is shorter than the published reports. Had I seated my bullets according to the published reports they would have been to long.
__________________
Retired Air Force 8th TFW The Wolfpack |
February 14, 2005, 07:51 PM | #4 |
Senior Member
Join Date: July 14, 2001
Location: State of Confusion
Posts: 2,106
|
Short throat!
OK, in that case, you need a shorter COL than the published specs, and you'll have to work out what is best for your rifle with each new bullet.
That's an unusual situation, but you seem to have handled it.
__________________
God Bless America --Smokey Joe |
Thread Tools | Search this Thread |
|
|