The 380 Auto, 116 years of service

[ChestnutLouie]

Where do you have the case mouth on this bullet? On the band in front of the crimp groove?
What gun needs it to be so large?

 

[Petrol & Powder]

Where do you have the case mouth on this bullet? On the band in front of the crimp groove?
What gun needs it to be so large?
View attachment 39857

ChestnutLouie wrote, "Where do you have the case mouth on this bullet? On the band in front of the crimp groove?"

For a semi-auto cartridge that headspaces on the case mouth - Yes, that would be taper crimped on that forward drive band in front of the crimp groove of the pictured bullet.

ChestnutLouie asked, "What gun needs it to be so large?"
I'm not sure what that question is referenced to.

 

[ChestnutLouie]

ChestnutLouie wrote, "Where do you have the case mouth on this bullet? On the band in front of the crimp groove?"

For a semi-auto cartridge that headspaces on the case mouth - Yes, that would be taper crimped on that forward drive band in front of the crimp groove of the pictured bullet.

ChestnutLouie asked, "What gun needs it to be so large?"
I'm not sure what that question is referenced to.

I understand about headspacing on the case mouth. 380 auto bullets are .355" in diameter and Lee lists that bullet at .358", do you size it?

 

[Winelover]

Bullet size has nothing to do with headspace. Most nines ( I don't/won't own a 380) will handle a .358 diameter cast bullet. A .380 is nothing but an underpowered 9 mm. I size mine to .3585 diameter............... for half a dozen different nines. Have gone as high as .360 diameter but they tend to bulge some of the thicker brass.

 

[Tomme boy]

Mine is a Ruger Security 380. I taper crimp about 1/2 way in the front drive band. When I sized them at 0.356" I was getting 6" groups at 15yds. So I sized a few at 0.358" and they just fell into the chamber. I loaded 20 to see how they shot and the group went down to 2" at 15yds.

 

[Petrol & Powder]

As stated above, 9mm should be .355" by the book. In reality, the groove diameter can be just about anything between .355 to .359 depending on the make.

 

[ChestnutLouie]

Mine is a Ruger Security 380. I taper crimp about 1/2 way in the front drive band. When I sized them at 0.356" I was getting 6" groups at 15yds. So I sized a few at 0.358" and they just fell into the chamber. I loaded 20 to see how they shot and the group went down to 2" at 15yds.

Thanks, useful information