Crimp marks? on casing

JungleCat7

JungleCat7

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Howdy, I'm new to reloading and loaded several boxes of 38 357 with no problem. I am starting to load 40 S&W and the first three have crimp marks or slight folds on the casing where the bottom of the bullet sits. Is this normal? if not what am I doing wrong?
Bob
 
this kind of middle crimp? (second and third from the left)
44_crimp2.jpg
 
if it's like this you need to make sure the case is chamfered and slightly expanded
Also the die might be screwed in a bit too much.
For straight wall cases that headspace on the mouth, only a slight taper crimp is required if any.

21.JPG
 
JungleCat7 said:
yes sir thats it what am I doing wrong and can I fire them?

Bob
Click to expand...

Back-up the seating die until no crimp is applied. See if that solves the issue.
For the already loaded ones, get the barrel out of the gun and try to chamber the rounds. If they chamber fine, you're good to go.
If the case chambers slightly out of battery compared to a "good" round, pull them out, reuse the bullet, powder, primer and throw the cases away.
 
If you see that your cases are wasp waisted you are over resizing your cases, the case only needs to be reduced in diameter enough to firmly grip the bullet. You will see this with tapered cases and carbide sizing dies with a single size ring in the base of the die.

Do not seat and crimp in the same operation, seat the bullets and then crimp.

A taper crimp should only be .002 smaller in diameter than the body of the case around the bullet. A taper crimp is more for streamlining the case mouth for smooth chambering than for griping the bullet.

crimp-4_zps7b8c9848.jpg


I even use a taper crimp on my .44 mag practice ammunition when using faster burning powders.
 
legi0n said:
21.JPG
Click to expand...

If your ammo looks like this then I suspect you're very badly adjusted on your seating and crimping die.''

Where this could easily happen is if you force a crimp early and then keep pushing down with the seating die. Or if you're crimping die is very badly set and trying to form a very tight crimp.

If you're seating and crimping in separate dies first off be sure that the first seating die is not set low enough that it forms a crimp. Almost all seating dies are also crimping dies so you need to make sure the outer barrel is up high enough that it doesn't try to form a crimp. Leave that for the second crimping station.

If using a three die arrangement then set up the seating and crimping combination operation as follows

  1. Start with the outer barrel screwed well up so it does not even think about forming a crimp.
  2. Adjust the seating screw so it seats to the proper OAL.
  3. Now back out the seating screw at least 5 or 6 turns so it will not engage while you're setting up the crimp.
  4. With the ram up fully screw in the outer crimping sleeve until you feel a very slight resistance. From here start lowering the test round and inspect for a crimp. Move the outer crimping barrel down in small increments until you have a very slight crimp. For .40 S&W the proper crimp is just barelly in at all. It should be almost straight with only the slightest of pinch on the bullet. These rimless rounds headspace on the case mouth so you don't want to crimp them hard into the bullet.
  5. With the crimp now set and the outer locknut tight and the crimp double checked and adjusted if needed it's time to screw down the seating screw until you feel it contact the bullet in the test round. Obviously the ram is fully up for this.
  6. You're done.

The die is now set to seat and crimp correctly and any sign of bulging like seen in that picture should be gone. Simply put if your ammo looks at all like this picture you have a badly misadjusted die and it's pinching the crimp very early then crushing the cases. You need to back the die off so that at full ram travel you just barely touch enough to get the desired crimp.

It's also only typical to use a roll crimp for rimmed ammo. On rimless ammo you need to keep to a very light taper crimp to ensure that the case mouth edge will still seat in the headspacing step in the barrel's chamber. So no serious roll crimp as shown in that .44Mag ammo picture.
 
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