Expander mandrel use with a Redding type S die

[Freediver111]

I’ve slowly switched all my FL dies to Redding Type S dies. The goal was to reduce overworking brass and set neck tension to roughly .001 to .002.
I’ve been doing this with my 6.5 for a while now, but just started working on a new .338 win mag and setting it up for reloading.
I bought a Type S for the .338 and purchased a bushing .002 under the size of a loaded round. So a loaded round measured .364” with both Nosler and Hornady brass. I purchased the .362 bushing.
When I measure the OD of the case mouth after resizing wit the expander ball removed, I’m seeing the OD come out at .360-.361. That seems like it’s still putting too much tension on the bullet.
Is a Sinclair Gen II expander mandrel the best way to finish a case for neck tension? I see a lot of how-to’s that basically suggest you remove the expander ball and just use a bushing .001 to .002 under loaded case neck size. Some mention using a mandrel after that step, some don’t.
So what’s some consensus? Is it always a good idea to go ahead and use an expander mandrel after resizing with a bushing die minus the expander ball?
Seems like it would be a good idea as a final step.
Thoughts? Thanks.

 

[Trek]

I’m following, but with 308. Decapping with a Lee die, then a Redding S FL with both the rod/expander ball removed... .336 (Lapua unturned brass) with a Redding nitride bushing in the top of the backed of an 1/8 (rattle). I then trim, prime and then use a Sinclair mandrel die with a carbide 307 mandrel before seating with a Wilson in-line die... I delay the mandrel expansion until after trimming... since I use dry carbon lube with the mandrel and allow that to be retained when seating (else it would foul the trimmer). Seating pressure is ~40 lbs. Good luck in your approach!

 

[Claluja]

Is your brass neck turned? Ask because the Redding S type with bushing is best used with neck turned brass. This is per Redding, and based on data.

If NT, try a bushing one size up. I like the nitride type.

Expander mandrel may be worth trying if not neck turned and/or if you decide to keep using current bushing.

 

[Freediver111]

Is your brass neck turned? Ask because the Redding S type with bushing is best used with neck turned brass. This is per Redding, and based on data.

If NT, try a bushing one size up. I like the nitride type.

Expander mandrel may be worth trying if not neck turned and/or if you decide to keep using current bushing.

Not neck turned. I’m not set up for that, and honestly didn’t really want to turn necks. I want accurate, but not with that much effort.

 

[A.Huggy]

I'm not sure I follow. Is there a specific reason to remove the expander ball inside the die? My Redding dies still have the expander ball in place and I get correct neck tension (about 1.8 thou with a bushing 2 thou smaller than a loaded round).

 

[jd138]

To the OP, I removed the expander (and decapper) from my Redding type S and use the Sinclair expander. I bought both turning and expanding mandrels as I intend on testing which my rifle likes better. Is a dedicated turning process better? Probably, but the expander is a quick, relatively inexpensive, although additional, operation. I also added in a couple other bushing sizes for testing.

 

[Tokay444]

I'm not sure I follow. Is there a specific reason to remove the expander ball inside the die? My Redding dies still have the expander ball in place and I get correct neck tension (about 1.8 thou with a bushing 2 thou smaller than a loaded round).

They’ve been shown to pull on the freshly sized shoulder and affect headspace.

 

[AKMarty]

I’ve slowly switched all my FL dies to Redding Type S dies. The goal was to reduce overworking brass and set neck tension to roughly .001 to .002.
I’ve been doing this with my 6.5 for a while now, but just started working on a new .338 win mag and setting it up for reloading.
I bought a Type S for the .338 and purchased a bushing .002 under the size of a loaded round. So a loaded round measured .364” with both Nosler and Hornady brass. I purchased the .362 bushing.
When I measure the OD of the case mouth after resizing wit the expander ball removed, I’m seeing the OD come out at .360-.361. That seems like it’s still putting too much tension on the bullet.
Is a Sinclair Gen II expander mandrel the best way to finish a case for neck tension? I see a lot of how-to’s that basically suggest you remove the expander ball and just use a bushing .001 to .002 under loaded case neck size. Some mention using a mandrel after that step, some don’t.
So what’s some consensus? Is it always a good idea to go ahead and use an expander mandrel after resizing with a bushing die minus the expander ball?
Seems like it would be a good idea as a final step.
Thoughts? Thanks.

Numbers for my 6.5 CM...

-.295” neck O.D. in fireformed brass.
-Case neck walls .0135-.0140
-Bullet diameter .264
-.291” crimped w bullet on neck of factory match ammo.

The Redding type S dies are waiting at home. Seems like a lot of brass work to me as well.

Following.

 

[trob_205]

For my 6.5cm I use the lee decapping die then Redding type s die set and remove the expander ball. Then I use a Sinclair expander mandrel after size. The bushing in the die I believe is .002 smaller than the mandrel. Ever since switching to this I find I get a much more even seating pressure from round to round as well. Using a charge master to throw H4350 and the above brass work and I can achieve a pretty decent SD/ES. I think the best SD I was getting before using the expander mandrel was 10-12 depending on the day and the first time out after switching I achieved this with my last 28 rounds. Was going to do 30 but I forgot until it was too late and only had the 28 left lol

 

[Saffer]

Numbers for my 6.5 CM...

-.295” neck O.D. in fireformed brass.
-Case neck walls .0135-.0140
-Bullet diameter .264
-.291” crimped w bullet on neck of factory match ammo.

The Redding type S dies are waiting at home. Seems like a lot of brass work to me as well.

Following.

Are you crimping your ammo?

 

[AKMarty]

Are you crimping your ammo?

I have the bushing dies. I intend to use neck tension for these. I’ve never used bushing dies. My .338 wm and 375 h&h I use the Lee factory crimp die.

 

[Paqueo]

In the past I have used Redding Competition Neck Sizers with Titanium Nitride bushings for a 308 Win.
Never managed to have proper neck run out numbers. Tried several things: bushing numbers up and down, a little sizing lubricant on the necks, neck turning, trim and debbur to square the case mounths prior to enter the bushing, "O" rings to allow the die to flute, only tighten the die lock ring after having the first case inside the die... even e-mailed Redding but nothing worked has I wanted - less neck run out than .002" - .003" (sometimes more).
Just quit. Using a polished Forster BR FL sizer I regularly get 0 up to .001" neck run out.
Recently had similar problems with Redding FL Sizer Type S with titanium nitride for a 6.5CM.
Tried what I already mentioned plus:
- Use the largest bushing that would still allow a proper hold of bullets - the expander ball wouldn't force the neck.
- Use a smaller bushing to allow the expander ball to correct any run out at the end or latter with a Sinclair mandrel.
- Also installed an "O" ring on the expander ball rod to allow some movement.
- Lapua brass annealed every shot...
Had to quit again the Type S and bushings plus the Sinclair mandrel and use a Forster FL sizer to get 0 up to .001" ES of neck run out, most cases only .0005" on Lapua cases not neck turned.

Only my 2 cents... may be long ones but just to share my frustration with the bushing type dies