Creases in cases...what am I doing wrong?

[Scooter1942]

I've been loading up some .357 Mag with 158gr and 180gr XTP's.


About one in five cases develop horizontal creases/bulges just below where the bullet base is seated. Most seem to happen with GFL brass. I have had no issues with Remington, Federal, or Winchester brass and have had only one do this with Starline brass. All have been with 158 XTP's. Is it just that this GFL once fired brass is exceptionally thin?

 

[BigMuddy]

First question; are you seating and crimping in one step? If yes, then that could be the reason. A Lee factory crimp die might help.

If it’s with one brand of brass it may be because it is thicker rather than thinner. More bullet resistance. Possibly a larger expander plug, or just running it slightly deeper could help.

Dan

 

[Scooter1942]

First question; are you seating and crimping in one step? If yes, then that could be the reason. A Lee factory crimp die might help.

If it’s with one brand of brass it may be because it is thicker rather than thinner. More bullet resistance. Possibly a larger expander plug, or just running it slightly deeper could help.

Dan

Yes…seating and crimping in same step.

 

[243winxb]

To much crimp? Different trim length brass may need a different crimp/ seat die adjustment.

 

[cattlelackranch]

You are crimping before bullet is seated far enough. Back off the crimp function or do it as a second step.

 

[CH4]

^^^^^^
This

 

[IAM Rand]

cases are not all the same length. When you go to crimp it will crease the longer cases. I have had this happen. I have not had a problem seating and crimping in one step with RCBS unless I hit a case that is longer. They should still shoot if they will load into the cylinder. It doesn't make any sense that 1 out of ever 5 is having this problem with the crimp being too soon. Check the case length. Doesn't have to be too much to cause a problem. If you got more of a crease it would be more of a difference.

 

[Greyman50]

Happened to me with certain projectiles, started rolling them on a lube pad and SLOWLY seat and crimp, no more issues.

 

[mtgianni]

The key to what is being said is the seating depth. The picture show the cannelure in different spots from the end of the case.

 

[Nevada Ed]

The longer 180 gr bullets need a little more "Love" when you marry then to a 357 case.

All the cases need to be the same length,
a good bell for the bullet is neededed as well as
a little lube to the inside of the case with a Q-tip or nylon brush.

Seat your bullets to the "Can" of the selected bullet
now ajust your crimp to finish the load.

In this mannor, if there is a small difference in length of case or bullet can placement
you will still get a finised load w/o a damaged case,if the powder amount is correct.

Those damaged cases will shoot, just mark them, since they will "Fail" earier than the rest of the lot, down the line.

Good shooting.

 

[Borderboss]

You'll get this if you resize the cases too small. The bullet will push the case out when it gets seated. Can you mike the case mouth opening after resizing?

 

[NFrameFred]

Just one man's opinion, it's never a good idea to seat and crimp in one step. Mixed cases (especially range brass) - varying lots, brands, wall thickness, length . . . too may variables for consistent results.
"Taper" crimping is somewhat of a misnomer; in my experience 'taper crimping' usually reduces the case mouth back to sizer die dimension, though in some circumstances I guess depending on the die/brand/setting it could be overdone. THe result of doing this in one step with a taper would be a bit of shaving at the mouth; thing is, I'm not familiar with a seater die with a built in taper crimp.
I'm with those that think using a seater die with a roll crimp in one operation is the cause of your problem. Just one man's opinion . . .

 

[M29since14]

Seat and crimp separately. Your problem should go away. It’s always controversial in some peoples’ minds but my money will always be do it in separate operations.

 

[BC38]

Yes…seating and crimping in same step.

To much crimp? Different trim length brass may need a different crimp/ seat die adjustment.

I think this is your answer.

When you seat and crimp in the same step the bullet may still be moving (not fully seated) when the crimping ring makes contact with the case mouth. So the bullet is still moving into the case at the same time that the crimp is increasing the case's "grip" on the bullet.

One force is trying to push it further into the case, the other is trying to lock it into position. Something has to give. In this instance it is the case wall below the bullet that "gives" and you get a wrinkle like what is shown in your photos. The thinner the brass, the more likely it is to wrinkle.

I think you need to adjust your seating/crimping die to apply the crimp just a tad later in the stroke of the press, or apply just a little less crimp.

Or you can switch to seating and crimping in separate steps. Personally I like seating and crimping in separate steps, even though it is a little more work. IMO it produces more consistent rounds, especially on rounds where you want a really firm crimp (like magnums).

But that's JMO, and YMMV...

 

[Warren Sear]

Do not lube the inside of the case or the bullet when seating bullets. Ever.

 

[nksmfamjp]

Is the crease on one side of all around? Also what seating plug are you using?

 

[alwslate]

Looks like your crimp might be just a bit before the case mouth is on the crimp groove.

 

[pasound]

Two steps. Seat, then crimp. Saw this problem for years before I discovered Lee factory crimp dies. Never one since.

 

[BC38]

Two steps. Seat, then crimp. Saw this problem for years before I discovered Lee factory crimp dies. Never one since.

FWIW, Lee may not even offer a FCD for every caliber you want one for. But there is good news! You don't actually need to find a Lee FCD for every caliber.

You can also use one seating/crimping die for seating only (back out/remove the crimp ring) and use another identical seating/crimping die for crimping (back out or remove the seating plug).

So, with proper adjustment, two identical seating/crimping dies can be adjusted and used to seat and crimp in separate steps, even without a Lee FCD.

Been there. Done that.

 

[JB4570]

What I see is way to much crimp, back it off a bit, get correct depth for the bullet and ease the crimp down and you're be good to go.