Adjusting seating depth

[Mike W1]

I have normally just used a dummy round to do this little job. Had a bit of trouble getting the OAL where I wanted it so I did a bit of measuring and figuring. Does this make sense?

SEATING DIE SCREW

Appears to be 20 tpi in Lyman .45 ACP dies

This would make it .050" per revolution

1/4 revolution would change it .0125" in length

1/8 revolution would change it .00625" in length

[SSGOldfart]

wouldn't that depend on the die body treads too??

[Mike W1]

wouldn't that depend on the die body treads too??

Wouldn't think so. I set the die body threads first and then adjust the seating screw to get the OAL.

[Garyshome]

If it's a .45 you might use your Micrometer or calipers. That is what I use. I check it in the mag and the chamber also.

[Mike W1]

If it's a .45 you might use your Micrometer or calipers. That is what I use. I check it in the mag and the chamber also.

Check mine with a dial vernier and a case gauge. Checking ain't the problem, it's fiddling around with that seating screw and trying to outguess it. Thus my original post, if I have a measured length how far to turn down the adjusting screw to shorten it. And not spend half the evening guessing!

[mdi]

If the turn/depth system works for you, great. I haven't had much difficulty setting my bullet depth, as I have my OCD in check (yeah, sure!) and a variation of .005" is OK with me. Keeping each OAL to less than .005" difference can be difficult 'cause of so many variables in bullets, brass, press slop. etc.

Same idea figgered for 7/8-14 thread die bodies...

[country gent]

Another trick is to use your calipers depth rod measure from top of seating stem to die body and you can adjust up or down whatever amount you think you need. IE stem measurement is 1.005 and you want .005 less. Adjust stem hieght to 1.000 and your there.

[Idz]

Here's a list from another forum. I can verify that Lee uses 5/8x18 seating stem

Seating Stem Adjustment
(Manufacturer - tpi)
*Forster/Bonanza - 32
**Forster/Bonanza - 28
C-H/4-D - 20
Dillon - 20
Hollywood - 18
Hornady - 18
Jones - 20
Lee - 18
Lyman - 20
RCBS - 28
Redding - 20
Wilson - 20

* 6mm and smaller
** .25 cal and larger

[Mike W1]

http://i171.photobucket.com/albums/u310/Mike4245/DieMod-2_zpsa45863a3.jpg
http://i171.photobucket.com/albums/u310/Mike4245/DieMod-1_zpsffae51a7.jpg

My morning project. Some crude reference marks with a file and a 3/4" nut ground down thin instead of that 5/8" that comes with the die. Added a 1/16" x 1/2"ID rubber O-ring and things are easier to adjust now. I have to credit Mr. Lee for the O-ring. Not overly nuts about them on the die body but here it's easier to "tweak" a small change in. Seems to work just fine.

[Green Frog]

I have a fool proof way to set the die for the first round if I have no dummy round to go by. I first insert the bullet and "bump" it down close to right. Then I back the seating die out until it no longer contacts the case neck or bullet. I then carefully bump the bullet in a little at time by bringing the seating stem in slowly, sometimes not even bringing the handle down all the way, until I get my COAL right. I then back out the seating stem about 3-4 turns and bring the die down to get the desired crimp. While the handle is all the way down on the now correct bullet, I bring the stem down to touch and lock everything down. Measure one last time for COAL and sufficient crimp, then begin loading. It took a lot longer to type this than it does to go through the procedure. That's my story and I'm sticking to it! 8-)

Froggie

[dudel]

I basically user Froggie's method with the exception that I lock the die down once the crimp is set, THEN I bring the seater down till in contact. No chance of moving the die while setting the seater.

He's right it takes longer to tell, than to do.

Don

[Mohillbilly]

+3 Froggie and Don

[Mike W1]

+3 Froggie and Don
I'm assuming you guys have 3-die sets and seat and crimp in one operation. I only use 4-die sets and those are separate operations then.

[dudel]

I'm assuming you guys have 3-die sets and seat and crimp in one operation. I only use 4-die sets and those are separate operations then.

Nope. Generally seat and crimp in two operations. I use whatever seater came with the die set, then crimp with an Lee Carbide Crimp die. Even easier to set up. For a given round, I adjust the seating die to the dummy round, and leave the crimp die alone.