First loads - trouble with seating die adjustment

tpcollins · February 25, 2009, 08:41 AM

After going back and forth with distance to the lands and depth of bullet options, I decided to seat the 70gr bullet a caliber's length and worry about moving the bullet closer to the lands later down the road.

I followed the instructions for the seater die setup and I was using a dummy cartridge to set up my depth but when I loosened the nut on the depth screw of my RCBS seater die, the die would spin inside the lock nut and throw my adjustment off. I have a lead shot under the brass screw in the lock ring but it doesn't seem to hold it solid. I must be tightening the nut on the depth screw too tight - should I use fingers only instead of a 7/16" wrench, maybe I could set double washers underneath to eliminate the nut from gripping the top of the die so much?

I saw some brass RCBS 7/8-14 lock rings online that I may order and put a double set to keep my dies from moving. Thanks.

whiplash · February 25, 2009, 09:27 AM

I do use a flat rubber washer under the seater stem lock nut. That keeps it snug enough but not loose. Your die lock nut/ring with the lead shot under the brass set screw should be tight enough. Once your set screw is set, you should be able to take a big wrench and snug the die down to the press. It shouldnt take a whole lot to keep it from moving around.

mkl · February 25, 2009, 10:09 AM

Use a pair of channel lock pliers to snug the lock ring down against the top of your press. That will keep the die body from rotating.

wncchester · February 25, 2009, 10:53 AM

" I decided to seat the 70gr bullet a caliber's length and worry about moving the bullet closer to the lands later down the road."

SEE! You getting smarter all ready!

There is no need to wrench any part of a die down hard, finger tight is good. If that galls you or your fingers are weak, just snug the various nuts slightly. There is no justification to buggering up your lock rings with pliers either.

Torquing that seater nut to the point of spinning the die is WAY over tight. All we need do is prevent accidental change, dies ain't like head bolts on a car engine!

The screw locking nut that came with your die is fine, you don't need any more "lock nuts" on top of them.

**Unclenick** · February 25, 2009, 11:04 AM

Just take a Sharpie or other magic marker and draw a line off the parts and onto the press to serve as a registration mark. Get all the parts loose for adjustment and use the line to return them to original position. If you don't like the looks of the line, use a pencil so you can remove the marks.

(Wncchester was posting while I was composing, so this is a bit redundant): By the way, tightness is not critical. I've seated bullets many times with the parts loose. Since the upward pressure of the ram presses the threads upward, they are in the same position as they would be when the nuts are tightened. You get a little more pre-loading from the tightening which makes the system more rigid and sets the die down a little more, but we are talking on the order of a thousandth of an inch or less, unless you've got dirt or foreign material in the die or press threads. For this reason I would leave the lock nuts loose and rely on the registration marks until your first correctly seated cartridge is made, then tighten them and check that nothing's moved appreciably (again relying on the marks).

Note also, that because brass relaxes after stretching, that if you create a correct seating depth by nudging a bullet into a case a little at a time, that when you do it all in one stroke with the same die setting the bullets will tend to come out a little high. This varies with the cartridge and the brass condition, so check for it after you've got your first cartridge correctly seated. You may find you need to turn the seater stem down a few thousandths more.

February 25, 2009, 08:41 AM	#1
tpcollins Senior Member Join Date: February 18, 2009 Location: SE Michigan Posts: 558	First loads - trouble with seating die adjustment After going back and forth with distance to the lands and depth of bullet options, I decided to seat the 70gr bullet a caliber's length and worry about moving the bullet closer to the lands later down the road. I followed the instructions for the seater die setup and I was using a dummy cartridge to set up my depth but when I loosened the nut on the depth screw of my RCBS seater die, the die would spin inside the lock nut and throw my adjustment off. I have a lead shot under the brass screw in the lock ring but it doesn't seem to hold it solid. I must be tightening the nut on the depth screw too tight - should I use fingers only instead of a 7/16" wrench, maybe I could set double washers underneath to eliminate the nut from gripping the top of the die so much? I saw some brass RCBS 7/8-14 lock rings online that I may order and put a double set to keep my dies from moving. Thanks.

February 25, 2009, 11:04 AM	#5
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Just take a Sharpie or other magic marker and draw a line off the parts and onto the press to serve as a registration mark. Get all the parts loose for adjustment and use the line to return them to original position. If you don't like the looks of the line, use a pencil so you can remove the marks. (Wncchester was posting while I was composing, so this is a bit redundant): By the way, tightness is not critical. I've seated bullets many times with the parts loose. Since the upward pressure of the ram presses the threads upward, they are in the same position as they would be when the nuts are tightened. You get a little more pre-loading from the tightening which makes the system more rigid and sets the die down a little more, but we are talking on the order of a thousandth of an inch or less, unless you've got dirt or foreign material in the die or press threads. For this reason I would leave the lock nuts loose and rely on the registration marks until your first correctly seated cartridge is made, then tighten them and check that nothing's moved appreciably (again relying on the marks). Note also, that because brass relaxes after stretching, that if you create a correct seating depth by nudging a bullet into a case a little at a time, that when you do it all in one stroke with the same die setting the bullets will tend to come out a little high. This varies with the cartridge and the brass condition, so check for it after you've got your first cartridge correctly seated. You may find you need to turn the seater stem down a few thousandths more. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

February 25, 2009, 09:27 AM	#2
whiplash Senior Member Join Date: January 18, 2007 Location: Idaho Posts: 334	I do use a flat rubber washer under the seater stem lock nut. That keeps it snug enough but not loose. Your die lock nut/ring with the lead shot under the brass set screw should be tight enough. Once your set screw is set, you should be able to take a big wrench and snug the die down to the press. It shouldnt take a whole lot to keep it from moving around.

February 25, 2009, 10:09 AM	#3
mkl Senior Member Join Date: April 25, 2008 Location: DFW area, Texas Posts: 494	Use a pair of channel lock pliers to snug the lock ring down against the top of your press. That will keep the die body from rotating.

February 25, 2009, 10:53 AM	#4
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	" I decided to seat the 70gr bullet a caliber's length and worry about moving the bullet closer to the lands later down the road." SEE! You getting smarter all ready! There is no need to wrench any part of a die down hard, finger tight is good. If that galls you or your fingers are weak, just snug the various nuts slightly. There is no justification to buggering up your lock rings with pliers either. Torquing that seater nut to the point of spinning the die is WAY over tight. All we need do is prevent accidental change, dies ain't like head bolts on a car engine! The screw locking nut that came with your die is fine, you don't need any more "lock nuts" on top of them.