New to handloading and am loading for my 30-378. There are several different COL's listed in the resources I have consulted. I hear you can customize it for your gun by leaving it long and trying to close the bolt and if it doesn't go, seat it deeper until it just does close. Not sure if that is right or not.
Best way to set COL
- Thread starter ru1234
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royinidaho
Well-Known Member
Here's what I do.
Start with a full length sized case with no primer.
Then cut three slots from mouth to the top of the neck at equal distances around the case mouth with a dremel tool and cutter blade.
Then completely debur everything and chamfer the case mouth.
The case mouth should now hold the bullet sufficiently to start it into the case mouth by hand.
Carefully chamber the dummy round and the leade should seat the bullet giving you the overall length that just touches the rifling with out jamming.
After removing the dummy cartridge from the chamber back off a bunch on the seating die and insert the dummy into the die. Run the ram up as far as you are going to then CAREFULLY run the seater screw adjustment down until it just touches the bullet.
Finally seat a bullet in an unprimed full length sized case to use as a standard.
HTH
Start with a full length sized case with no primer.
Then cut three slots from mouth to the top of the neck at equal distances around the case mouth with a dremel tool and cutter blade.
Then completely debur everything and chamfer the case mouth.
The case mouth should now hold the bullet sufficiently to start it into the case mouth by hand.
Carefully chamber the dummy round and the leade should seat the bullet giving you the overall length that just touches the rifling with out jamming.
After removing the dummy cartridge from the chamber back off a bunch on the seating die and insert the dummy into the die. Run the ram up as far as you are going to then CAREFULLY run the seater screw adjustment down until it just touches the bullet.
Finally seat a bullet in an unprimed full length sized case to use as a standard.
HTH
RU
the method you described can work but it normally gives you about .020-.050 bullet into the lands. That is normally what is called the "jam"
If the gun has a magazine and you want to use it, then the mag length will determine COL.
www.sinclairintl.com has a seating depth tool for under $30 that allows you to accurately measure exactly where a particular bullet touches the lands. That way you can determine what seating depth your gun likes as far as on or off the lands.
Depending on the exact bullet you are using, you may have to adjust your COL (if shooting single shot) to the desired point. Not all bullets are the same length from the ogive to bullet tip.
BH
the method you described can work but it normally gives you about .020-.050 bullet into the lands. That is normally what is called the "jam"
If the gun has a magazine and you want to use it, then the mag length will determine COL.
www.sinclairintl.com has a seating depth tool for under $30 that allows you to accurately measure exactly where a particular bullet touches the lands. That way you can determine what seating depth your gun likes as far as on or off the lands.
Depending on the exact bullet you are using, you may have to adjust your COL (if shooting single shot) to the desired point. Not all bullets are the same length from the ogive to bullet tip.
BH
Buffalobob
Well-Known Member
The 30-378Wby will have about 0.375 inches of freebore, I beleive. You should double check that number. You may not be able to reach the lands.
Old school way was to take a candle to a dummy rnd and black the bullet with the smoke, then push the dummy in. If it is seated to far it will show where it touches the lands.
If this is a bad way of doing this, will someone correct me?
Thanks
If this is a bad way of doing this, will someone correct me?
Thanks
SamSpade
Well-Known Member
Easy way to set COL
Here is a link to an easy to use tool for setting COL.
http://www.predatormastersforums.com/ubb...page=0#52212062
Here is a link to an easy to use tool for setting COL.
http://www.predatormastersforums.com/ubb...page=0#52212062
markwinwood
New Member
use your neck sizing die to just kiss your fired case.
you will need to find the sweet spot to have just the right
grip on the bullet. seat a bullet with fingers and make sure it is concentricit and sticking out. place in chamber adn close bolt real slow, open and measure, best way i know how to find COL.
you will need to find the sweet spot to have just the right
grip on the bullet. seat a bullet with fingers and make sure it is concentricit and sticking out. place in chamber adn close bolt real slow, open and measure, best way i know how to find COL.
