is this normal when sizeing 9mm luger brass?

[gpwelding1]

i have been full length sizeing some mixed headstamp 9mm's.when i started loading them i noticed that some,such as cobon+p headstamp,had the appearance of being narower just below where the bullet was seated.it isnt like that on all of them.just the corbon +p's and some that were head stamped cbc.is this normal?and does anyone know what the ones head stamped cbc are?

 

[spelsh]

CBC (Companhia Brasileira de Cartuchos) - I think it's Magtech?

 

[gennro]

yeah it is magtech

 

[MtnCreek]

Measure the wall thickness of the cbc vs the other brass. Does the cbc have a thicker wall?

 

[gpwelding1]

yep,it and the corbon+p's are both thicker.

 

[gpwelding1]

but is the taper below the bullet seat going to hurt anything?its just barely noticable,but i didnt know if it could affect gas pressure.

 

[MtnCreek]

It's not uncommon to see a slight buldge around the seated bullet. If it chambers properly and you're within your load data charge weight / seating depth, everything's good to go.

Edit Second thought: If you're already pushing pressures to the limit, the slightly reduced case volume could be a problem. If you're within your manuals data, no problem. If you're loading your own +p+, 9mm major, ... there could be a problem.

 

[gpwelding1]

ok,thanks for the help.

 

[Galil5.56]

but is the taper below the bullet seat going to hurt anything?its just barely noticable,but i didnt know if it could affect gas pressure.

The "wasp waist/hourglass" condition you are seeing below the seated bullets base after sizing is normal, as is a uniform, reasonable concentric bulge where the shank of the bullet expands the case... This is a great sign, and means your dies and expander are working well together, allowing for good bullet pull that helps limit/stop bullet setback.

 

[Doug b]

Carbide dies and over sizeing

Those of us that remember reloading with steel dies were used to seeing a very small ring around the bullet in some brass but by no means everyone of them.With the change over to carbide inserts it it appeared on every caseing and became a talking point on the range and in gun shops.Most opinions were this is a good thing but over works the brass.
After a few years a gun writer wrote this is due to not being able to machine carbide steel to the perfection of tool steels so die makers erred to the side of over sizeing.

 

[1SOW]

The "Coke-bottle" shape is normal in reloaded 9mm luger.
When you size an empty case, you see a tapered "straight-wall" case. When you bell the case mouth, seat the bullet and then taper crimp, the case mouth is re-formed to the bullet base. This makes it slightly larger than the original case-mouth. The rest of the case is unchanged.

 

[tightgroup tiger]

Many 9mm cases with a heavier wall thickness expands the brass backout when the bullet is seated, I look at this area to see if my bullets are seating straight. I have found if I try to go to fast on my single stage press that it will seat some out of straight.
This bulge can be useful. I don't like to see it but with the bullet set-back problems that 9mm have where the bullet seats itself deeper from the recoil of the last shot, raising the pressures of the shell to an unsafe limit, I don't mind seeing it. I know my bullets are good and tight.

good luck

 

[fguffey]

I have two 45 ACPs that do not like cases, when loaded, look like they swallowed a bullet, the 2 ACP like ammo that is store bought, new, over the counter, so that leaves me to purchasing new ammo or make my reloads look store bought. Not a problem, after seating and crimping I remove the bulge with a sizer die, after sizing 1/3 of the case the measurements are the same as new, over the counter ammo and the two pistols can not tell the difference.

F. Guffey

 

[gpwelding1]

ok.i just wanted to make sure they were ok.thanks