Inside Case Dimensions, .45 ACP?

[HartwickCo]

I've got a question about the inside of a .45 ACP case... in the diagram below, does anyone know the measurement of the smallest inside dimension? I'm sorry that I don't know the name, but it's the plate in which the flash hole is punched.

To put it another way, what's the largest thing you could insert in a .45 case without it ever touching the sides, including that taper inward where the powder sits? I assume that something with a diameter of .3953 would push against that tapered side.

Any help is appreciated!

 

[jackieschmidt]

I just happen to be out in my shop.
I took a new WW 45 ACP case and using a blind hole small hole gage, came up with .390 inch.

 

[HartwickCo]

I just happen to be out in my shop.
I took a new WW 45 ACP case and using a blind hole small hole gage, came up with .390 inch.View attachment 1420912

Wow, this is AMAZING! Thank you!

I had no idea how thick the case was at that taper, and whether it was thicker than the rest of the case for structural reasons. This is really, really helpful.

 

[GLShooter]

Of courses every brand of case may well be different.

Greg

 

[divingin]

Of courses every brand of case may well be different.

I think that should read "will be different". More so since in the 112-odd years since that drawing came out, there have been countless changes in manufacturing, bullets, etc. About the only things I'd say were constant are the exterior dimensions (and I wouldn't really be shocked to see differences there, either.)

I'm a little curious, though, as to the OP's original post. What are you going to be sticking in there?

 

[HartwickCo]

I think that should read "will be different". More so since in the 112-odd years since that drawing came out, there have been countless changes in manufacturing, bullets, etc. About the only things I'd say were constant are the exterior dimensions (and I wouldn't really be shocked to see differences there, either.)

I'm a little curious, though, as to the OP's original post. What are you going to be sticking in there?

"What are you going to be sticking in there?"

Don't ask questions you don't want the answers to.

Seriously though, I'm playing around with some ideas for case reforming/resizing on some obsolete calibers, and I want to work on cheap/easy rounds as I sort out the process. If I can't make it work with .45, I can't make it work on a weird one.

 

[divingin]

Okay, thanks for the clarification.

Good luck with your project.

 

[HartwickCo]

Of courses every brand of case may well be different.

Greg

Thanks, Greg -- I should probably invest in some proper tools to make these measurements. If anyone has any suggestions, I'd love to hear them!

 

[jackieschmidt]

The tool I showed you will measure any ID within it’s range right down to the base.

 

[XTR]

There is a guy on here who has necked a 45ACP down to .22 ,,, just for academic reasons (and he sometimes has too much time on his hands.....

@Rtheurer

 

[dcali]

Out of curiosity, what are you trying to do?

 

[HartwickCo]

The tool I showed you will measure any ID within it’s range right down to the base.

Thanks, Jackie -- I see that's Starrett, everything I've ever gotten from them has been awesome and will hold up longer than I will. I'll keep my eye out for a set!

 

[HartwickCo]

There is a guy on here who has necked a 45ACP down to .22 ,,, just for academic reasons (and he sometimes has too much time on his hands.....

@Rtheurer

Ok, that is wild. I saw a photo of a '12 Squirrel' the other day and it looked awesome. I fully support this kind of tinkering for the sake of it, very cool.

 

[HartwickCo]

Out of curiosity, what are you trying to do?

Hey Bison, I checked out your site -- really impressive, I wish I shot well enough to take advantage of your bullets.

I'm actually trying to find different ways of manipulating cases without deforming them, clamping them down vertically on a soft post (copper?) in a way that doesn't cause any bulge/deformation at the base.

 

[dcali]

Hey Bison, I checked out your site -- really impressive, I wish I shot well enough to take advantage of your bullets.

I'm actually trying to find different ways of manipulating cases without deforming them, clamping them down vertically on a soft post (copper?) in a way that doesn't cause any bulge/deformation at the base.

Depending on what you're trying to do, maybe make a lead casting of the inside of the case?

 

[HartwickCo]

Depending on what you're trying to do, maybe make a lead casting of the inside of the case?

Ohh, that's a fantastic idea. I could actually probably get away with a rubber cement casting since I wouldn't need precision to the thousandth. A bit of lube, rubber cement, and a toothpick in the middle to make it easy to pull out.

Thanks for these ideas, it is really helpful to get fresh perspectives!