I was reloading for my 357 maggie the other day, Winchester 357 brass,using my left-over 125 gr. JHP bullets, both Remington and Speer. Cases fired maybe 3 times. Medium crimp in the cannelure of the bullets. C.O.L at or slightly below published max. figure. None of the cases jammed against the front edge of the cannelure.

4 out of the 100 cases buckled very badly, all with Speer bullets, which have always worked fine before. I pulled the bullets, salvaged the powder, and destroyed the cases.

The brass was ~ the same lengths, below published max. length , as close to the same as trimming can get them, and were expanded with a Lyman "M" die for bullet seating, I was using the seat/ crimp function of my RCBS carbide die set. No visible problems, but that has never happened to me before. My loading manuals weren't much help.

I know that is only a 4% failure rate, and that may be acceptable, but I am not happy with it. Can anyone suggest what I might do different/better in the future?
Thanks

Collapsed during seating of the bullet?

Not enough bell and the bullet is catching the case mouth edge.

Collapsed during the crimping stage?

Check to make sure you are not seating the bullet too deep. Remember that in most dies the crimp tends to seat the bullet a bit deeper. Back off on the seating die. I'm sure you insured that the cases were trimmed to within +/-.002" of each other.

Bushmaster wrote:

Collapsed during the crimping stage? Remember that in most dies the crimp tends to seat the bullet a bit deeper. Back off on the seating die. I'm sure you insured that the cases were trimmed to within +/-.002" of each other.

Bushy:
Yup: Crimp stage, and checked length too!

Is a puzzlement.

Yup...And I should have said "seating Stem" too. Something is irregular during some of the seating/crimping stage.

See if you can figure out what is common to the ones that are collapsing...If you are belling too much you may be catching something in the die.

Seat and crimp in seperate steps.
Make sure the inside case neck is chamfered just slightly.

Great skb2706...That solved the problem. I've been loading .357 magnum for over 22 years and have had various problems along the way. Solving those problems without finding a patch has made me a better reloader. Getting a Lee FCD would solve the problem. but would not tell us what the real problem is or was. I still don't have a FCD for .357 magnum. I do, however, have a FCD for .38 Special. But I know why I needed the FCD for .38 Special.

Yes I would believe that a FCD will, in fact, solve his problem, but he still will not know what the problem was. Sooo Let us work on that. Besides he may want to shoot his .357 magnum and it will take time for a FCD to arrive.

Check the four bullets diameter and make sure they were not out of tolerance.

Anytime I've had issues with the case buckling it's been because of too much crimp or the bullet not seated deep enough to allow the crimp to roll in correctly.

If you want to seperate the stages you can do so with the spacer that usually comes with a 357/38 die set
.
seat a bullet to length without crimping
Back you seating stem way out
Set your crimp and lock down the lock ring
when you seat, put the spacer in, set your OAL, (it's quick and easy if you have a dummy round to set it with) and snug up your retaining nut finger tight
take spacer back out when you want to crimp

I have had this happen with nickel plated brass. I actually roll the bullets on my lube pad before seating them when loading nickel cases. Seems to solve the problem. Never had a problem with plain brass.

Thanks, everyone. Checking the bullets, I found that none of them was even close to jamming into the front of the cannelure, so something else is amiss.

I had set up my reloading for separate seating and crimp operations, using the RCBS die to seat, then my Dillon Pro crimp die, which will both taper and roll crimp. I used the taper crimp feature for softer Berry's plated and Hornady swaged SWC bullets, and did very effective medium roll crimps for the rest.

THEN, I decided to get efficient, all of a sudden. Oh, yeah; seat and crimp in one operation! Save TIME!

Reading Veral 3: 16-22, he says he seats all his bullets by feel. When he feels the brass hit the bottom of the crimp groove or cannelure, that's enough, sez he. It works well enough, but my press is a compound, and the necessary "feel" evades me, so I decided to do it the old fashioned way...again.

I had a LEE FCD for my 357, and didn't see that it did all that much good. My ammo actually improved once I stopped using it. Probably I was doing something wrong.

Oh, well, back to the ol' drawing board....

Roklok: I have about 150 nickle-plated brass...doesn't lubing your bullets contaminate the powder?

Seat/crimp in one opperation: On my (LEE) machine (and others I've tried) I can get a nice seat/light crimp in one opperation if the die is adjusted propperly.

I first set up the die using an empty case.
Run the ram up all the way, screw die down till it just touches the case mouth. I'm then about 1/4 or so turn of the whole die away from a light crimp (usually, other factors not included).

Then I'll lower the ram, add a bullet, set seat depth to case mouth side of the can., then, screw die in 1/4 to 1/2 turn for crimp, and, the case mouth then ends up on the upper end of the can. closest to the bullet nose .

The best crimp I can get before the case buckles will withstand 3 whacks with my pulling hammer, for whatever that's worth. Heavier crimps done in a sperate opperation require more flogging w/ the puller- a good thing with slow powders/heavy slugs IMHO.

If I try and crimp any heavier with the combo-die the case buckles due to the fact it does not have as much of a 'sizing' taper to the die like the FCD does, and, on final the bullet seats another .050" before the crimp is done forming- then bottoms on the can., and there's no getting away from the fact the ram goes up during seat/crimp. I like to have a final seat with the mouth of the case on the upper third or more of the can. so the crimp can fully form/flow.

If you want a heavy(er)-crimp, you either need to back off the seater post-seating and re-stroke the ram or do it as a seperate opperation.

Sidenote- If I'm using a soft hollowpoint, the seater mushes the point and 'arrow-head's' it during an attempt at a firmer than normal crimp as the seater bottoms the Bullet out on the land of the can. closest to the nose of the bullet. This occurs just prior to buckling on certain cases. Some brass I've noticed is more rsesistant to buckling than others, but in any case, the nose of my HP gets a little mushed if I get too agressive with the crimp on the seat/crimp die.

The standard crimp the combo die provides should be acceptable for light target loads. But for the heavy's/huntin' stuff, I use a heavy crimp and do it as a seperate opperation.

In either case, your trimmed cases, regardless if mixed make or not, must be exactly the same length or you can forget about consistency.

Case flare has nothing to do with this type of buckle (post-seating)...if the case was flared too much it would not go into the die, and, probably have a split mouth, at least with my dies.

Your mileage may vary, just my .02

I almost always seat and crimp handgun loads in one operation.

To set up my die I first turn the seating stem way out, so it won't accidentally touch anything. I put a case in the holder, run the ram up and then screw the die down until it touches the case. Then I back off about a half turn. After that I take a charged case, place a bullet in the mouth and run the ram up. I screw the seating stem down until it contacts the bullet. Lower the ram, screw the stem down some, raise the ram to start seating. Repeat the last sequence until I have the bullet seated to the canelure.

Then back the seating stem out again. Raise the ram and turn the die in until it contacts the case mouth. Lower the ram, adjust the die down, raise the ram to start the crimp. Repeat the last sequence until you get the crimp you want. Tighten the die locking ring.

Finally I take the round I just crimped and run it back into the die. Now turn the seating stem down until it makes firm contact with the bullet. Remove that round and try another, seating and crimping in one operation. Check the seating depth and crimp of this round in case you need to make a minor adjustment. Then let her rip!

Obviously if you're only loading one load/bullet you'd only have to do all this once. After that it's already set up. But what's the fun of only one load?!?!

Sniper, ever figure it out?

Pumpkinslinger wrote:

Sniper, ever figure it out?

Not quite. All but he 4 were O.K., so I checked lengths with no results, so, I readjusted my seat/crimp dies per your suggestion, especially the "let 'er rip" portion, and loaded another 100, with no problems. So far, so good, but, as they say, it's still early!

My main problem now is, what is the difference between a light crimp and a medium one? I guess if it looks good, go for it. Seems to have worked so far.

As far as I know it's just an "eyeball" sort of thing. I guess you could try measuring it with calipers but I've never seen any kind of numbers for that. What do you more experienced guys think?