Following FL bushing sizing with expander mandrel dwell time

[SGK]

I see a good number of people recommending following a bushing sizing with a 4-5 sec dwell time in an expander mandrel, the aim being consistent 'neck tension'. Without custom mandrels this constrains the tension to 1 thou. I'd love to hear further thoughts on the topic...

 

[Dusty Stevens]

You can do whatever dwell time makes your seating force read consistent

 

[AJC]

Is this a spinoff of joe salts die dwell time.

 

[Willie]

I hold it at a 5 count, but don't know that it makes a big difference. There is gonna be a variance in springback anyway. What a mandrel does do, is direct springback inwards, toward the bullet. Can't prove it, but that seems to benefit neck tension. I need to get a force dial seater, one of these days.

 

[Puzzaz01]

I hold it at a 5 count, but don't know that it makes a big difference. There is gonna be a variance in springback anyway. What a mandrel does do, is direct springback inwards, toward the bullet. Can't prove it, but that seems to benefit neck tension. I need to get a force dial seater, one of these days.

That'll definitely tell you what you need to know.

Darrin

 

[SGK]

I guess my first question is whether this is good practice (bushing size down and expander mandrel up). I'm currently loading for .223 Rem. My (rather crappy) Hornady ELD-M 52 gr bullets measure 0.2235". I've turned my Lapua cases to a high side of about 0.013". I was using a 0.248" bushing to target 1-2 thou neck tension. The bushing produces/targets a 0.248-0.026 = 0.222 ID and the expander mandrel will increase that to 0.223 leaving rather little neck tension.

 

[Webster]

I see a good number of people recommending following a bushing sizing with a 4-5 sec dwell time in an expander mandrel, the aim being consistent 'neck tension'. Without custom mandrels this constrains the tension to 1 thou. I'd love to hear further thoughts on the topic...

There should be no affect due to dwell time. Appears to be a made up thing. People will swear they see an affect but the copper industry has spent a lot of time studying this if for no other reason loss of switch contact pressure.

https://www.copper.org/applications/industrial/DesignGuide/performance/tempstress03.html




From this chart you can see 1 hour at 20C no change in relaxation. Ten hours a little change.

https://www.copper.org/applications/industrial/DesignGuide/performance/

 

[dkhunt14]

I guess my first question is whether this is good practice (bushing size down and expander mandrel up). I'm currently loading for .223 Rem. My (rather crappy) Hornady ELD-M 52 gr bullets measure 0.2235". I've turned my Lapua cases to a high side of about 0.013". I was using a 0.248" bushing to target 1-2 thou neck tension. The bushing produces/targets a 0.248-0.026 = 0.222 ID and the expander mandrel will increase that to 0.223 leaving rather little neck tension.

That's why they make different sizes of mandrels. Size the case a hair smaller then needed and slightly expand with a mandrel to even them out. Matt

 

[SGK]

I've only seem 1 per calibre and each 1 thou less than nominal. So .223" for 22 cal.

 

[hogpatrol]

K&M offers another option:

https://kmshooting.com/case-neck-expanding.html

 

[Dusty Stevens]

And porter precision products offer one that you can get mandrels for $3ea and can get them in any dimension you want

 

[Joe Salt]

Is this a spinoff of joe salts die dwell time.

AJC What I do Is Size them twice, up once spin 180 and size again. Now I also use a little tighter bushing like MATT said and then us an Ex pander.

Joe Salt

 

[AJC]

AJC What I do Is Size them twice, up once spin 180 and size again. Now I also use a little tighter bushing like MATT said and then us an Ex pander.

Joe Salt

I watched your video and found it very interesting. Currently trying a five count in the die. Dont have pin guages yet to go the other way.

 

[TrxR]

And porter precision products offer one that you can get mandrels for $3ea and can get them in any dimension you want

Where do i find this die? I cant seem to find a link to one.

 

[SGK]

I watched your video and found it very interesting

Link?

 

[Joe Salt]

Wrong Joe I'm Joe Salt!

Joe Salt

 

[Dusty Stevens]

Where do i find this die? I cant seem to find a link to one.

http://036d541.netsolhost.com/porter/

Call kenny