[Edsel]

...will it work for .380 ACP?

Redding Tech Support says it won't.

Can't figure out why.

Not sure if it has something to do with the 9mm case having a more pronounced taper compared to the .380 ACP, or that the seating stems aren't long enough (?).

As opposed to Redding's, Hornady's Custom Grade New Dimension Bullet Seater Die accommodates 9mm Luger, .380 ACP, and .38 Super.

I don't have all the components in for testing just yet...

 

[Malicious Compliance]

Redding tech support ain't SIG customer support. You can't call back numerous times and get different answers on each call. If the Redding tech says no, I'd take that as gospel.

 

[Edsel]

I may end up with a rogue Hornady in the pistol die collective, then...

Accumulating waaay too much junk.

 

[Flash LB]

I don't know about the Hornady, but I can tell you that a Lee seating die works just fine on .380 ACP. I did it once, accidentally. Mrs. Flash didn't manage to catch the one .380 that was in with the 9MM empties.

I only noticed when I picked it up to put in the loaded rounds box.

 

[Malicious Compliance]

Flash, am I reading this correctly? It sounds like you built a 380 ACP to 9mm OAL? We are talking a difference of what, ~.200" between 380 ACP and 9mm OAL? I'd be curious to know if the cartridge built to proper 380 ACP OAL successfully.

 

[Flash LB]

Flash, am I reading this correctly? It sounds like you built a 380 ACP to 9mm OAL? We are talking a difference of what, ~.200" between 380 ACP and 9mm OAL? I'd be curious to know if the cartridge built to proper 380 ACP OAL successfully.

That's exactly what I did, but the seater punch has enough adjustment that I could easily use it for my .380 reloading as it's nowhere near bottomed out.

I seat my 9MMs to 1.080" and my .380s to 0.930", so the difference in OAL was 0.150"

The cartridge was built successfully and had structural integrity, so I assume it would have actually worked if I could chamber it successfully in a .380 chamber, which I seriously doubt. In a 9MM chamber, it would have undoubtedly gone off, albeit with fairly high pressure, but probably not enough to do any damage as I was using 5 grains of Unique in 9MMs at that time.

The bullet I used had a pretty long profile and a long, tapered ogive. I don't remember who the manufacturer was at this point as it's been a few years ago.

Edited to add:
After posting, I was thinking about that particular reloading mistake and realized that I had used one of the main features of the Lee Factory Crimp Die. It's advertised as being just the thing for consistent crimps as it's very tolerant of differences in case length and I think this proves it beyond a shadow of a doubt.

 

[Malicious Compliance]

OK, thanks.

On a bit different tangent, I bet that cartridge built to 9mm OAL with the 380 ACP case would have fired with no abnormalities regarding pressure. The chamber size of the cartridge with the 380 case (internal volume of the case with bullet installed) would have been theoretically the same (at least very similar) as it would have been if a 9mm case was used. With minimal crimp surface, it may have been more prone to bullet set back, but I bet the pressures would have been similar to what you had with 9mm cases.

 

[Flash LB]

You're right, as the math shows around a 10% difference in volume, so as I said, it wouldn't have been catastrophic....

Just embarrassing. It's the only time in all these years that it's happened, but fortunately I do a QA on the loaded rounds so these things get caught before them become problematic.

 

[Malicious Compliance]

Sounds like you have a pretty effective case sorter!!

 

[Flash LB]

She does a great job and has for years, so she's allowed a mistake here and there.

She excels at sorting the .45 ACP SPP and LPP cases so I don't have any major hang ups or surprises when loading on my progressive press.

And where she's really great is at the range, asking other shooters (not in our group) if they are keeping their empties and when they say no, she sweeps them down to my lane.

 

[disseminator]

...will it work for .380 ACP?

Redding Tech Support says it won't.

Can't figure out why.

Not sure if it has something to do with the 9mm case has a more pronounced taper compared to the .380 ACP, or that the seating stems aren't long enough (?).

Hornady's Custom Grade New Dimension Bullet Seater Die accommodates 9mm Luger, .380 ACP, and .38 Super.

I don't have all the components in for testing just yet...

I can hazard a guess. I have the Redding Competition Seating Die for 357 SIG that I use to great effect on my Dillon 550b.

I wondered if it would be suitable for 9mm as well since they are the same OAL and bullets. After looking at it and reading the design idea behind the Comp Series Dies, I believe it is because the Precision dies rely on the clearances to be just so, so the bullet and case can "float" on the cushion of air and provide correct alignment for bullet seating.

I'm gonna go make a dummy round and see if it works.....

 

[Edsel]

I wondered if it would be suitable for 9mm as well since they are the same OAL and bullets. After looking at it and reading the design idea behind the Comp Series Dies, I believe it is because the Precision dies rely on the clearances to be just so, so the bullet and case can "float" on the cushion of air and provide correct alignment for bullet seating.

I'm gonna go make a dummy round and see if it works.....

Hey, thanks.

Once I get all my components together, I'll try it out myself.

I still need to send all my Redding Expander Dies (the mandrels, anyway) in for remanufacturing.

 

[Edsel]

...I believe it is because the Precision dies rely on the clearances to be just so, so the bullet and case can "float" on the cushion of air and provide correct alignment for bullet seating.

You're right.

I played around with the Competition Seating Die for 9mm Luger using a Federal Hyrda - Shok in .380 ACP and HST in 9mm.

With the .380 ACP, the dial has to be turned all the way below zero to seat a bullet; if it actually can seat the bullet properly, that's the longest OAL you'd be able to achieve (stem's bottomed out). The seating stem has to be at least 7mm longer, or the bottom of the die body has to be shaved 7mm shorter for it to be usable.

In addition, unlike the .40S&W / 10mm dies, which probably have an identical body taper and are less "headspace - critical," lookit the pichers above...

The .380ACP round on the left wobbles a fair amount in our die, but not the 9mm round on the right (seating stem removed to illustrate "headspacing").

The reasons are apparently:

1. Stem Length
2. The "chamber" is cut almost like a Case Gauge.