9mm Muffin Top issues

[sasquatch981]

Here are some photos of the bell I have on my cases, and the squidgy seating issues I am having.  This seems to happen with coated bullets, and now the Rainier Ballistics.  Both of them were 115's with the round nose profile.  It does not seem to be an issue in my PCC, or a Rock Island 9mm hicap, but it does seem to lock up the glock with the tight aftermarket barrel.  Ideas on what to do?

[michael.flitcraft]

Looks like too much crimp


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[Ken6PPC]

Do not seat and crimp in the same die...  

[Scootertheshooter]

Does look like too much crimp plus , clean that brass[emoji12]

Possibly not enough bell?

[tyler2you]

Looks like you're seating die isn't adjusted properly.  It appears you're crimping before the bullet is fully seated.

[bowenbuilt]

Like Tyler said the bullet is still moving while its being crimped. Your seating die may be screwed down too far or are you trying to seat and crimp at the same time?

[Sarge]

Clearly moving while crimping. Make it stop!

[sasquatch981]

Seating and crimping are two separate dies.  Dillon 650,   Dillon seater, and Lee Factory Crimp.

 

So from the sounds of it, maybe the crimp die, is set to "low" and is pushing the round down when crimping?

 

 

[michael.flitcraft]

Seating and crimping are two separate dies.  Dillon 650,   Dillon seater, and Lee Factory Crimp.
 
So from the sounds of it, maybe the crimp die, is set to "low" and is pushing the round down when crimping?
 
 

It's swaging the bullet - you're making the inside diameter of the brass at the mouth smaller than the outside diameter of the bullet. Use just enough crimp to barely remove the belling, or crimp the mouth of the brass at sammi spec.


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[Sarge]

41 minutes ago, sasquatch981 said:

Seating and crimping are two separate dies.  Dillon 650,   Dillon seater, and Lee Factory Crimp.

 

So from the sounds of it, maybe the crimp die, is set to "low" and is pushing the round down when crimping?

 

 

Ugh, back that FCD out so it's just acting as a  crimper and not a sizer.

[Sarge]

After zooming in it's obviously the coating being peeled off. Crimping too tight won't do that. Pushing plated bullets in further after crimping will. Even if just removing the bell, plating is super thin and fragile

[AzShooter]

Get a Taper Crimp Die.  It will solve your problem.  You just want to eliminate the bell no crush the bullet in with the crimp die.   Also you can reduce the amount of bell you are using.

[bowenbuilt]

If the seating die also will crimp, back the seat die body out and re-adjust the seating stem further into the die. You should be able to see which station is causing this. As was said before the bullet has to be moving and moving a lot to do what you have pictured. If the bullet was static you could crimp it into and it would not roll the coating back.

[MemphisMechanic]

With the FCD here's how you begin to check this: run the center of die down all the way, then back the body of the die out of the toolhead. Lift a round that has a properly seated bullet up into station 5, and screw the die in until you feel contact being made. Now slowly thread it in, until you get the crimp you want - just barely removing the flare - and see what you wind up with.

 

This will turn the FCD into a traditional crimping die. Which is good for diagnostic purposes in this case.

 

Once you verify it's the problem, you can slowly return it to resizing-duties if you wish. Or leave it there.

[noylj]

Get a Lee Taper Crimp Die (not the FCD).

>This will turn the FCD into a traditional crimping die. Which is good for diagnostic purposes in this case.

If you leave the carbide ring, you will find that over-large bullets, like my cast lead bullets, will get swaged down. If you remove the carbide ring, the FCD is a great crimp die.

 

Taper crimp is NOT to hold the bullet—and too much will bulge the case and  you'll lose bullet tension.

All you want to do is remove the case mouth flare.

Just for any one's information:

How to adjust a seating die to seat and crimp (not recommended).

1) Adjust seating stem all the way UP

2) Put expanded/flared case in shell holder

3) Raise Ram

4) Screw die down until you just feel the crimp section contact the die mouth.

5) Screw the die body up 2 full turns and apply a small amount of lock ring tension so die doesn't move easily

6) Place bullet on case and raise ram

7) Lower seating stem (make sure die body does not move) until it just contacts the bullet. 

8) Lower round and screw seating stem down one turn to seat the bullet.

9) Adjust the seating stem until target COL is achieved.

10) Raise seating stem completely out of the way

11) Screw die body down until it just contacts the case mouth

12) Lower the round and screw the die body down 1 turn.

13) Raise ram and crimp round

14) Lower ram and inspect crimp.

Best is to remove barrel from gun and ensure that the round "plunks" when dropped in chamber. If any case mouth flare is visible and round won't plunk, adjust for more crimp. Diameter at case mouth should be close to 0.378-0.380" and straightedge placed along the case body should not show "air" at the case mouth from residual flare.

I assume you could use a case gage, but I've never used one.

15) When crimp is good, with round in die, lock the die body down tight with the lock ring and lower the seating stem down to just touch the bullet.

 

I found that even with a single-stage press, using a separate crimp die was easier and testing showed that my accuracy was better when the steps were separated.

Edited August 6, 2017 by noylj