Sizing & Seating Dies for Cast Accuracy

  • 174 Views
  • Last Post 29 April 2023
Wm Cook posted this 29 April 2023

When loading for long guns, what’s your preference for sizing & seating dies?

Assuming you’re loading for more than one caliber, have you consolidated your choice for dies and the methods you use when loading for cast accuracy?

Do you use bushing (neck size only) dies?  Bump dies?  In-line seater dies like Wilson?

Thanks, Bill Cook.

 

ps:  Always learning.

Patience isn’t a virtue, it’s a delay tactic.

Attached Files

Order By: Standard | Newest | Votes
RicinYakima posted this 29 April 2023

For 25/20, 32/20 and 30/30 I use RCBS Cowboy dies. 30/06 match ammo I use a honed out MP sizer and a Wilson seating die. This was done before bushing dies were invented. 

Everything else are older Redding dies for long guns, except for 50/70 which are Lyman. 

HTH;s, Ric

Attached Files

  • Liked by
  • Bud Hyett
Shopdog posted this 29 April 2023

Over the counter RCBS dies here.

Love my M dies.... turning custom spuds are so fast N easy.

Have made seater stems,there's some real improvements available on these. Have also swaged factory seater stems...

This "can" really work out nicely. Doesn't occur in every die but,what I'm doing is chucking up the factory stem and swaging the original cup tip to form a flared end.

Then,once that's done...and straight,then you peel off a little from the OD to where it is a much closer fit to the inside of that die. It isn't a "universal", every die supports this process.

Lots more to it all. Good luck with your project.

Attached Files

Wm Cook posted this 29 April 2023

I hate to sound stupider than I really am but are you talking about the flairing M die from Lyman?  Bill.

Patience isn’t a virtue, it’s a delay tactic.

Attached Files

Shopdog posted this 29 April 2023

Not really a flaring op,although it is within the capability of these dies.

It's a two diameter,stepped spud. The minor diameter is the lower,and enters the case first.

It pushes all case issues outward,and sets your interference(neck tension). IME there aren't any set in stone #'s for this. You're gonna have to test what your rig prefers. Generally I go with comparing .002", vs .004".

These numbers are far enough apart that it cuts past most of the associated "noise" in making smaller changes. Rarely do I run much less than .0015.... and never more than .004... a crimp is probably more useful than going full gorilla grip(more than .004).

The upper step is held to bullet diameter,+- a smidge. The goal in this step is to have absolute parallelism with the lower,minor diameter. Prior to final seating,the bullet is hand pushed into this top part.....

The trick is this preseat before heading to the seater die. I've tested,retested,tested again.... presenting with high attention paid to getting the bullet started dead nuts,always results in less loaded cartridge run out. To the point that "checking" run out is a waste of time. Similar in concept to;

If you're casting zen,and consistency is sharp.... weighing bullets is a waste of time. We're nipping these issues BEFORE,they're problems. Hard to put into words. Trash in,trash out if you will. Get the bullet straight before the seating op,don't rely on the seater to fix anything.. it can't.

Attached Files

Wm Cook posted this 29 April 2023

Ric, I think Brian is describing the Lyman M flailing die but you described your sizing die as  “…. a honed out MP sizer”.  MP doesn’t ring a bell with me but the honing operation sounds like you’re using it as a bump die just to keep the shoulders just far enough forward that the bolt closes with a little tension.  Or maybe you honed out the neck to get the tension you wanted? 

Maybe I’m pretty far out in left field with the way I do things but all I’ve ever done was neck size and keep an eye on the case OAL so it doesn’t shorten up.  I don’t know what the PSI is/was but I shoot in the 1500 to 1950fps range. So they’re moderate loads that doesn’t seem to stress the brass much.

If it takes any more than a light pressure to close the bolt I FL size then go back to neck sizing after the next firing.  Thanks to both of you for the help.  Bill.

Patience isn’t a virtue, it’s a delay tactic.

Attached Files

  • Liked by
  • Ken Campbell Iowa
Close