Crimping .357 Magnum - How Important Is It?

[Enfield47]

I've been having a heck of a time with crimping my first .357 reloads. I'm using new Starline brass and a Lee carbide die set (no factory crimp die). The problem I'm having is that some cases (averages about 1 in 12 or so) will buckle a little in the middle of the case when crimping. I've backed the die out to where I'm barely crimping at all and it still happens. I've seen a variance in the case lengths of up to 2 thousands of an inch after sizing and I think the longer ones are the ones that buckle.

So how important is the crimp for the .357 round? Can I get away without crimping, or am I asking for trouble? I'm using 700x powder and 158 gr SWC Xtreme plated bullets. I know 700x isn't the best powder but up to 4.9 grains will keep the bullet velocity below 1,200 fps and should make for a good practice round from what I've read.

[hermosabeach]

I have shot a lot of 700x

If you are downloading the rounds to almost 38 special pressure loads, you almost don't need a crimp.

The super hot 110 grain JHP need a crimp.

147 wadcutters and heavier bullets when loaded light have plenty of tension from the surface contact area.

[hermosabeach]

You can also measure the OAL and then fire 5. Then unload and measure the OAL of the 6th round. Did the bullet move?

[JagerDog]

Those have a cannelure? Should be rolling that brass into the cannelure. Might adjust your seating depth to better accomodate.

Are you doing combined seat/crimp or separate ops?

[G-Man WC]

Depends what your loading them in. I'd want \ have a fair crimp
when pushing rounds in the side of my marlin 357 lever action rifle.
-g

[Gryff]

Without a crimp, you risk the bullets shifting forward in the brass under strong recoil. This could possibly lock up your revolver if the OAL lengthens too much.

[ojisan]

Are you seating bullets and crimping at the same time?
Doing these operations separately really helps.

And even though straight wall cases and carbide dies officially means you don't have to lube the cases, a little lube does go a long way.

I use Dillon Rapid Polish additive with walnut media to tumble dirty cases.
The cases are clean and slightly slick to the touch when done.
They really go through the dies smoothly.

New brass can be really dry, maybe try a spray can type of case lube....just a light mist on them.

[stilly]

I've been having a heck of a time with crimping my first .357 reloads. I'm using new Starline brass and a Lee carbide die set (no factory crimp die). The problem I'm having is that some cases (averages about 1 in 12 or so) will buckle a little in the middle of the case when crimping. I've backed the die out to where I'm barely crimping at all and it still happens. I've seen a variance in the case lengths of up to 2 thousands of an inch after sizing and I think the longer ones are the ones that buckle.

So how important is the crimp for the .357 round? Can I get away without crimping, or am I asking for trouble? I'm using 700x powder and 158 gr SWC Xtreme plated bullets. I know 700x isn't the best powder but up to 4.9 grains will keep the bullet velocity below 1,200 fps and should make for a good practice round from what I've read.

Keep that 700-x for .45 and .38, use H-110 instead...

[chknlyps2]

I have buckled a few .357 myself.... I know that WTF feeling when you just realized you ruined a case that you don't have bags of. Variations in case length I found to be the reason it has happened to me, I seat and crimp in the same pull of the lever and I have resorted to "feel" and not going till the press lever stops.

I set the die to crimp on the average length of the cases and get use to the feel of the resistance right at the end of the press stroke, when I feel that same resistance before I am bottomed out I pull the round out and inspect... If the crimp is good I leave it at that, some times I have to put it back in the shell holder and give it a little more.

I have also found that half of the cases I buckled were still able to chamber in the pistols cylinder and they were ironed out when fired and look good as new.

[J-cat]

Those don't have a real cannelure to crimp into. You are roll crimping into a fake cannelure. Why don't you seat the bullet deeper and roll crimp over the shoulder instead?

[JagerDog]

Those have a cannelure? Should be rolling that brass into the cannelure. Might adjust your seating depth to better accomodate.

Are you doing combined seat/crimp or separate ops?

Separate op can eliminate a lot of issues. With combined op, you're still pushing the bullet in as you form the crimp.

[ojisan]

^ Yup.
You are trying to push the bullet in that last little bit just as the crimp reaches full bite.
The irresistible force meets the immovable object.

[CSACANNONEER]

I just loaded a bunch of extreme 158g bullets over 3.3g of 700X in .38spl and I crimped them.

[Calif Hunter]

I'd adjust the die out and the seating plug in as needed to seat the bullet to the right depth, so the crimp would not be as severe and see how that worked. If the plated bullets (like most plated) do not have a real cannelure, you could be "over-crimping."

[CSACANNONEER]

You can always use the seater just to seat the bullets and then, in another step, remove the seating stem, adjust the die down a little and just use the seater/crimp body to crimp the bullets in a separate step.