casing deforming ?

[email protected] · April 30, 2006, 10:14 AM

While reloading my 380 casings{new and used starline}, I get a bump like ring mid casing after bellowing and bullet seating, I use Reading dies and they tell me this is normal. Lee factory crimp swages the bullet which I do not like. Reloads fire great. I just want to continue trying to improve my reloading. Any suggestions?

Leftoverdj · April 30, 2006, 10:38 AM

That ring can be one of two things. The most common cause, and it's nearly universal, is that your sizing die is small for the brass you are using. Manufacturer make dies to size even the thinnest brass enough to hold the bullets. When the brass is expanded back out by the expander and the bullet, you get a minor coke bottle shape. It's nothing to worry about.

The second possible cause is that some brass has more of an internal taper than other brass. When the base of a bullet is seated down into that taper, the brass is bulged out at the base of the bullet. When that happens, the ring is larger in diameter than the brass before or behind it. I have seen this many times when flushseating WCs in .38 Special +P+ brass. I would not expect it in .380, but you can measure the ring to check. It would not be a problem if your loaded cartridge will drop in and out of the chamber. It could be a considerable problem if the cartridge must be pushed pushed into the chamber and will not drop free of its own weight.

The case must have a little room to expand to release the bullet. If it is wedged into the chamber, there is no room to expand and pressures are raised considerably.

Rico567 · May 1, 2006, 02:10 PM

Some combinations of dies and cases give this "coke bottle" effect. I started experiencing it with .357 Magnum using Lyman dies around 35 years ago. Some other calibers I load show no trace of it. Since it doesn't affect the performance of the ammo, I don't worry about it.

April 30, 2006, 10:14 AM	#1
[email protected] Junior Member Join Date: March 28, 2005 Location: Columbus, Ohio Posts: 2	casing deforming ? While reloading my 380 casings{new and used starline}, I get a bump like ring mid casing after bellowing and bullet seating, I use Reading dies and they tell me this is normal. Lee factory crimp swages the bullet which I do not like. Reloads fire great. I just want to continue trying to improve my reloading. Any suggestions?

May 1, 2006, 02:10 PM	#3
Rico567 Senior Member Join Date: October 19, 2005 Posts: 162	Some combinations of dies and cases give this "coke bottle" effect. I started experiencing it with .357 Magnum using Lyman dies around 35 years ago. Some other calibers I load show no trace of it. Since it doesn't affect the performance of the ammo, I don't worry about it. __________________ "Dear reader, suppose you are a member of Congress. Now, further suppose you are an idiot. But I repeat myself." - Mark Twain

April 30, 2006, 10:38 AM	#2
Leftoverdj Senior Member Join Date: October 15, 2004 Posts: 934	That ring can be one of two things. The most common cause, and it's nearly universal, is that your sizing die is small for the brass you are using. Manufacturer make dies to size even the thinnest brass enough to hold the bullets. When the brass is expanded back out by the expander and the bullet, you get a minor coke bottle shape. It's nothing to worry about. The second possible cause is that some brass has more of an internal taper than other brass. When the base of a bullet is seated down into that taper, the brass is bulged out at the base of the bullet. When that happens, the ring is larger in diameter than the brass before or behind it. I have seen this many times when flushseating WCs in .38 Special +P+ brass. I would not expect it in .380, but you can measure the ring to check. It would not be a problem if your loaded cartridge will drop in and out of the chamber. It could be a considerable problem if the cartridge must be pushed pushed into the chamber and will not drop free of its own weight. The case must have a little room to expand to release the bullet. If it is wedged into the chamber, there is no room to expand and pressures are raised considerably.