Seating die adjustment uniformity

[PRCslut]

Given that all if not most modern seating does run an industry standard thread to mate with pretty much any press. If this is true, wouldn’t one turn of a die adjust seating depth by the same amount across the board. It doesn’t matter what caliber it is, the die is physically moving X amount up or down per rotation. For example, 6.5 creed die gets rotated one full turn down and makes a 10 thousandths change. Now if you were loading 308 win and made the same rotation, you should have made the same 10 thousandths change.

In my head this has to be true. I know 10 thousandths isn’t actually the correct value. Does anyone know the correct value.

 

[Rocketvapor]

Standard size dies are 7/8 X 14.
One turn would be 1/14 of an inch.
A lot more than 10 thousandths.

 

[Kracken McGraw]

Standard size dies are 7/8 X 14.
One turn would be 1/14 of an inch.
A lot more than 10 thousandths.

Yes, plus you shouldn’t be turning the whole die like you would on a sizing die.

 

[Old Navy]

Yes, plus you shouldn’t be turning the whole die like you would on a sizing die.

Right on. I hate to own up to this but I actually read the directions that came with my my Foster seating dies. They work great as the result.

 

[PRCslut]

I know it’s not 10 thousandths. I even said that in the post I was using it as an example. I just wanted to know how much the value was so I can start breaking it down

 

[JFrank]

Are you familiar with the PMA micro adjust due ring ? This could provide some insight.

PMA Micro Die Adjuster Pro

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www.pmatool.com

 

[Kracken McGraw]

I know it’s not 10 thousandths. I even said that in the post I was using it as an example. I just wanted to know how much the value was so I can start breaking it down

What brand of seating dies do you have?

 

[memilanuk]

I know it’s not 10 thousandths. I even said that in the post I was using it as an example. I just wanted to know how much the value was so I can start breaking it down

So... find out how many threads per inch (tpi) your seating stem has. Might have to call/email the manufacturer.

Once you have that number, pull out a calculator, and divide 1 (as in one revolution) by that number. That should tell you how far it will move per turn.

As an example, using the standard 7/8-14 tpi thread on most reloading die *bodies* (yes, I know you're not turning the whole die, but the example still holds), you get one (revolution) divided by 14 (tpi). 1 / 14 = 0.0714, or a little under 72 thousandths of an inch per rev. 9 thou per eighth of a turn, etc.

Find out the tpi of your seating stem, and you should be able to work it out the same way. Or you could do it empirically by seating a bullet, make a witness mark on the stem / die, then turn it a full rev and seat another bullet, then compare the two.

 

[PRCslut]

What brand of seating dies do you have?

Rcbs match master and Hornady match

 

[rdb8847]

Seat a bullet extra long. Take a measurement OAL Turn the seating stem one revolution and take a second measurement OAL. Do the math. Maybe do it a few times to verify.

 

[Dave M.]

I know it’s not 10 thousandths. I even said that in the post I was using it as an example. I just wanted to know how much the value was so I can start breaking it down

.072”

 

[pavementends]

Of course you could lay the seating stem on a ruler/scale/tape measure and count the number of threads in one inch and then do the same calculation as above to get it in thousands.

 

[BoydAllen]

Given that all if not most modern seating does run an industry standard thread to mate with pretty much any press. If this is true, wouldn’t one turn of a die adjust seating depth by the same amount across the board. It doesn’t matter what caliber it is, the die is physically moving X amount up or down per rotation. For example, 6.5 creed die gets rotated one full turn down and makes a 10 thousandths change. Now if you were loading 308 win and made the same rotation, you should have made the same 10 thousandths change.

In my head this has to be true. I know 10 thousandths isn’t actually the correct value. Does anyone know the correct value.

One does not adjust seating depth by turning a die body in the press threads. It is done by rotating the seating stem or a micrometer adjustment that controls the seating stem. Some seating dies have built in provision for crimping. For most rifle reloading most shooters chose not to crimp, so in those instances where the die has that provision, it must be backed off enough from touching the shell holder to deactivate that feature. What is commonly done by die body rotation is set the amount that bottle necked case shoulders are moved back (bumped). The common die and press thread is 7/8-14. To get the amount of die position change per rotation of the die in the press divide 1 by 14, which will give an answer of approximately .071.

 

[Webster]

Given that all if not most modern seating does run an industry standard thread to mate with pretty much any press. If this is true, wouldn’t one turn of a die adjust seating depth by the same amount across the board. It doesn’t matter what caliber it is, the die is physically moving X amount up or down per rotation. For example, 6.5 creed die gets rotated one full turn down and makes a 10 thousandths change. Now if you were loading 308 win and made the same rotation, you should have made the same 10 thousandths change.

In my head this has to be true. I know 10 thousandths isn’t actually the correct value. Does anyone know the correct value.

The bullet ogive shape determines where the seater contacts the bullet.

 

[Rocketvapor]

If you wanted to change seating depth 0.005" how far would you twist the seating stem?
25.2 degrees?
Would that be CW or CCW?

 

[Kracken McGraw]

If you wanted to change seating depth 0.005" how far would you twist the seating stem?
25.2 degrees?
Would that be CW or CCW?

If you turn it left that would be right.

 

[Clancy]

I’m sure the OP is long gone but this is a great way to adjust if the gun isn’t worth a WILSON seater, but if it’s not worth a Wilson, should we really have it?

 

[Kittitas George]

Using a Vickerman seating die, it is very easy to set the seating dept. After I have the COAL length, I make up an uncharged case, no powder, to set the die again if I load a different bullet. I Also have a piece of tape on the die with a witness mark for different bullets. Nosler now carries Vickerman dies, I've been told, but haven't confirmed.

 

[Infrequent Shooter]

Seat a bullet extra long. Take a measurement OAL Turn the seating stem one revolution and take a second measurement OAL. Do the math. Maybe do it a few times to verify.

this is the method I would try.

 

[hpshooter]

If you wanted to change seating depth 0.005" how far would you twist the seating stem?
25.2 degrees?
Would that be CW or CCW?

Depends--trick question without stating the desired result. Into or out of the rifling, that is the question!