.380 rounds not fully chambering

T

turtlehead

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I am having a problem with a new batch of reloads not chambering fully. Am using a new bullet for the first time. It's a Berry's 100 grain .356 diameter seated to .98 COL.

In the past I had been using Rainier bullets that were .355 seated to .98 COL. Never had a malfunction with those.

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The cartridge is getting stuck in the chamber and causing an out of battery situation. I believe the bullet is getting stuck in the lands. After forcibly clearing the last malfunction the case was pulled away from the bullet. That's the one in the picture.
 

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Different nose profiles necessitate different OAL's.

There are a number of causes of out of battery situations, but if the bullet is getting stuck in the lands you can pretty much guarantee that the problem is too long an OAL for that bullet.

You can shorten the OAL, go back to the old bullet, or have someone ream the chamber/throat/leade so that the new bullet will fit.
 
20180204_090810_resized.jpg

Having a little trouble with the pictures. Hopefully that worked.

So I put a few of the rounds through the press again and seated them deeper to approximately .78 COL. Now they seem to chamber OK.

Not sure I want to fire those rounds. Just trying to figure out what the problem is.
 
Just to make sure, mark the bullet with a black marker and try to chamber it. If the bullet is hitting the rifling, you will see where the black has been rubbed off. Also, try the "plunk test". Basically a cartridge is a peg and a chamber is a hole. For a peg (cartridge) to enter a hole it must be smaller than the hole (chamber). Whenever there is a fit problem, measure.

In your case perhaps you will need to shorten the OAL as the two bullets may have a slightly different profile...

https://thefiringline.com/forums/attachment.php?attachmentid=102664&d=1470501918
 
You need to do THIS to understand your max OAL. Just try it and shorten the oal until it passes....drops out.

It is called the plunk test.
 
Well they are definitely not passing the plunk test as can be seen in the last picture. That's one of the original rounds at .98.

They do pass at .71 - .78. They do not just drop out, however.

They did drop out fine when tested in the case gage.
 
So I have a few questions.

Will I have to work up a new load using the new COL?

Can I run these long cartridges back through the seating die and re-crimp them?
 
You SHOULD work up a new load. Question for you... how close to max was the original loading?

If the cartridges you already loaded are crimped... no. If you try to seat them deeper, you may cut through the plating (assuming you are talking plated bullets.) You could still fire them, but they probably won't be the most accurate rounds evarr.
 
First of all, they must drop out of the actual barrel freely.

Second, the OAL should end up .9....something. Is your case bell hanging up n something? Is the chamber clean as a whistle?

The sticking should be the bullet touching the rifling when the case mouth touches the chamber shelf.

Does a sized only case drop in and out?


Does factory ammo plunk fine?
 
Because case volume in the little .380 is so small, seating the bullet deeper will pump up the pressure pretty quickly... I found this out with 9mm and Unique. I'm not super familiar with TiteGroup, so I don't know how forgiving it is...
 
Factory ammo plunks fine.

Sized case drops fine.

Understand that I have no problem trashing this batch of reloads. Unfortunately I have about 600. :(
 
Is the chamber clean as a whistle
Click to expand...

...and I wondered about that myself. OP went to a slightly larger bullet, if there is residue (lead, etc) jammed up against the chamber shoulder, the larger bullet would wedge there, too.
 
If you are handy with math... and you have a leftover Rainer bullet to measure...

Measure the length of the bullet. You really need to figure how much deeper the bullet is being seated vs the older bullet.
 
Another example.

Long ago I was loading for one 9mm and everything was wonderful, added a second and all of a sudden I was having the same problem you describe. The rounds I had been making and using would not "plunk" into the second gun. As it turned out the second gun has a much tighter camber than the first gun. I turned the crimp dies down 1/4 turn and everything was sweet again.

Not saying this is your problem but it is another item to consider.
 
I have no more Rainier bullets left over. They were flat based. The new bullets are hollow based. I'm not handy enough with math to calculate THAT difference.
 
turtlehead said:
Well they are definitely not passing the plunk test as can be seen in the last picture. That's one of the original rounds at .98.

They do pass at .71 - .78. They do not just drop out, however.

They did drop out fine when tested in the case gage.
Click to expand...

Are you sure about those OAL's? The case should be .680. .71 would have the whole bullet buried inside the case except the very tip.

The key is to find the max OAL that will work with the bullet. Just using any random OAL is not a good answer and can result in pressure problems. I'd guess some where around right around .98 or just under. Finding the max OAL is important for small rounds such as .380 ACP & 9mm. For rounds like 38 Special or even .45 ACP the OAL is important but much more forgiving pressure wise.

You might be able to reseat the rounds a smidgen deeper and get it to work. Depending on how the bullet was crimped and how much neck tension you have, it might work out just fine. However you might reseat the bullets and loose all neck tension and the bullets just fall out, or somewhere in-between. Every time I seat a bullet deeper after the original seating I do a test to see if the bullet is loose. If you can press the round on a hard surface with thumb pressure and the bullet sinks deeper into the case you have a problem. The neck tension can vary between different brands of brass so it is necessary to test a large sample if not every round.
 
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