case body to shoulder mushrooming

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Randall

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While reloading some assorted brass .223 loads I noticed the shoulder to case body junction mushrooming out while seating the bullet.I have never seen this before.I checked the bullets diameters and they were right.Any ideas?
 
There could be a couple ofpossibilities but it sounds like you might have the seating die screwed down to far. Try backing it of a bit, you should have space between the die and shellholder. What might be happening is that the case is being forced into the crimp and with the case being to long it buckling the case. With normal dies this is a common problem. To get around this I normally will run a case in the up position and then turn the die in till I feel resistance( that is the mouth of the case coming into contact with the crimp section of the die) and then back off a thread or two. You might also checking the length of the brass as some may require trimming. For this type of crimp to work properly the cases must all be the same.

The Lee factory collet crfimp die is designed a different way and will not do this by the way.
 
That could be it,I took the die off my 550b and used it on my single stage by screwing it down to touch and then backing off 1 full turn.
 
Place case in ram and run it all the way up. turn seating die in until you feel it lightly touch the case, then back it up by a half turn. Turn seating stem down(ram up) until bullet is at crimp groove, back seat stem out a couple turns. Now turn the die down until you get the crimp you want, lock the die with lock rings. With the bullet still in the die and all the way up, turn stem down until it touches the bullet, lock the stem with lock nut. You should hav the right seating depth and the right crimp, although it may take a slight tweeking!

Jimmy K
 
Before you go with everyone's suggestion of backing out your die preventing the crimp ring from buckling your brass let me ask you a rather important question.

Have you measured your brass length and if so how long are the longest pieces in the aforementioned batch?
 
Randall said:
The longest was right at max length.
Click to expand...

and I'll bet those are the ones getting buckled. What your die has done is told you it's time to trim your brass.

Here's what I'd do

1. trim your cases to the trim to length

2. adjust your die 1 turn out of the lock ring

3. Buy a Lee FCD and start crimping in a separate step

4. Rejoice
 
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