A Riddle, a Question, or What the Heck?

[Engineer1911]

I've done a little reloading since 1974, and have about 45 die sets in the "tool boxes" . I've reloaded calibers from 380 ACP to 45-70, including one wildcat, the 30 Herrett. I loaded enough ammo to shoot out the rifling on a TC barrel, 1500 S&W rifle, and a custom stainless steel barrel on 25- o6.

So this is the tale of interest. I was asked to reload 270 Winchester brass into new ammo for sale at the Outdoor Range. I cherry picked the "best brass" out of 2 five gallon buckets of range brass and got 300+ pieces. I was looking for 'normal' primers, 270 Win head stamp, no signs of difficult extraction, only factory once fired brass without sizing die marks.

I checked the decapping stem on my 270 Win sizer die: diameter = 0.275", checked the Speer bullets: diameter = 0.277". Now the fun begins. About 50% of the brass will not pass a new 270 bullet through the case mouth, but a .257 bullet drops through with clearance. There are NO scratches on the case neck or shoulder. The neck ID measures between 0.263" and 0.268".

The max case length for 270 Win case is 2.540" . Sized cases measure 2.530" to 2.543" . There is a wildcat cartridge called a 6.5 - '06 shooting a 0.264" bullet, but case length is 2.494" (same as 30-06).

How can once fired, factory ammo have "fired necks" that are 0.010" to 0.015" smaller than loaded ammo? This is a simple question about a physical dimension on a fired brass case. No need for a statistical study on accuracy of my
Mitutoyo dial caliper or 1" micrometer. Bullet OD was measured correctly and case mouth ID was consistent either at or near 0.265" or 0.279" .

 

[bruce381]

spring back? no bullet to hold them open or i do not understand your question.

 

[Ivan the Butcher]

Two possibilities I can think of are 1) shot in the wrong gun. 2) Virgin brass was loaded into your 6-06 wildcat and fired in that gun.

Ivan

 

[Nevada Ed]

maybe a wildcat 256 Newton........... ?

Odd that there are no sizing marks on the brass.

 

[Cdog]

I have nothing in the way of an explanation, but your experience with things that simply don't add up makes me feel better about stuff I've not been able to reason.

I'll be watching this thread.

 

[jake1945]

"Brass spring back" Which is why fired brass can be extracted from chamber. When you reload the brass, the expander button will bring the brass back to proper size.

 

[gwpercle]

My first thought was brass spring back also . Brand new brass , only fired one time is still "springy" it hasn't work or age hardened and the neck sprung back . Most reloaders don't measure or even think to try a bullet in once fired brass ... just resize it and carry on .
Also note that fired brass will be shorter in length ...then when run through a sizing die ... it gets longer ... another weird happening ...
some assume brass gets longer on firing but it don't .
Gary

 

[Nevada Ed]

My first thought was brass spring back also . Brand new brass , only fired one time is still "springy" it hasn't work or age hardened and the neck sprung back . Most reloaders don't measure or even think to try a bullet in once fired brass ... just resize it and carry on .
Also note that fired brass will be shorter in length ...then when run through a sizing die ... it gets longer ... another weird happening ...
some assume brass gets longer on firing but it don't .
Gary

Are you saying the brass case..... Reverse flows, in the chamber ?

 

[mtgianni]

If your sizer button is 0.002" smaller than the bullets it makes sense that they will not pass through. You might need a slight flare on the brass to allow the bullet to enter. Neck tension should be good when you do have them loaded. I assume you were asked as you had a class 6 FFL?

 

[Engineer1911]

Back to Basics -- The Answer

The brass is tumbled in a Harbor Freight cement mixer. The paddle blades / mixing blades inside the drum beat up the case mouth.

The case mouth is undersize 0.006" to 0.012" NOT the entire case neck. Most of the brass was shiny from the tumbler. About 50 pieces were "out of the bucket" and had not been tumbled at the indoor range.

When I slightly flared the case mouth, the rest of the case neck was slightly oversized so a 270 bullet easily entered the neck.

It was the tumbler, not the rifle(s) or the brass.

 

[gwpercle]

Are you saying the brass case..... Reverse flows, in the chamber ?

Not exactly ... think about the chamber , its dimensions are larger . the fired brass expands and fill the larger chamber , a little spring back and the case can be extracted ... it is now larger in diameter in the body , and neck ... the brass will be shorter .
When the body and neck get squeezed down smaller in a Full Length sizing die ... the brass gets longer. The squeezed down , re-sized , brass has to go somewhere and the neck is the easiest place for it to grow longer ...nothing to stop it from "flowing"(?) in that direction .
I don't know if what happens in the chamber is "reverse flowing" what us old guys call it is enlarging ... would that be reverse flowing ...when you re-size a fired case is that "reverse flowing"?
So many new terms to keep up with ... I get lost sometimes.
Gary

 

[max503]

edited edited

 

[Nevada Ed]

Not exactly ... think about the chamber , its dimensions are larger . the fired brass expands and fill the larger chamber , a little spring back and the case can be extracted ... it is now larger in diameter in the body , and neck ... the brass will be shorter .
When the body and neck get squeezed down smaller in a Full Length sizing die ... the brass gets longer. The squeezed down , re-sized , brass has to go somewhere and the neck is the easiest place for it to grow longer ...nothing to stop it from "flowing"(?) in that direction .
I don't know if what happens in the chamber is "reverse flowing" what us old guys call it is enlarging ... would that be reverse flowing ...when you re-size a fired case is that "reverse flowing"?
So many new terms to keep up with ... I get lost sometimes.
Gary

In a way, I was questioning your statetment.
In a rifle chamber, the brass can only move to where there is space.
Usually by expanding outward and also the shoulder, moving forward, when fired.
The only brass that I know of that shrinks is my 38 special cases.
I have yet to trim one.

So the cement mixed did it....... huh?
Looks like plan "B" is needed.

 

[jcelect]

I assume you were asked as you had a class 6 FFL?

You admitted your intent is to sell remanufactured ammo in your original post. No class 6 FFL is about the fastest way to earn some time in the "gray bar motel"! Liability insurance will probably cost more money than you will ever make and your selling to the public at your local range ? ! ? !
jcelect

 

[Engineer1911]

You admitted your intent is to sell remanufactured ammo in your original post. No class 6 FFL is about the fastest way to earn some time in the "gray bar motel"! Liability insurance will probably cost more money than you will ever make and your selling to the public at your local range ? ! ? !
jcelect

I am a range employee reloading for the range. The range has an FFL with the necessary insurance and business license.