Too much crimp?

[Lee Q. Loader]

The picture is my starline 357 brass after shooting 125 XTP with 20.5 grains of 300MP. A pretty stout load.
See how you can still see the crimp?
I crimp these per Lee instructions for a heavy crimp. Raise the ram, screw until it touches the bullet, lower ram, screw one full turn.
What do you think?

 

[Fine Figure of a Man]

Is it an accurate load?

 

[troy fairweather]

You will know when you over crimped.

 

[Lee Q. Loader]

Is it an accurate load?

Yes, actually it's quite accurate.

 

[crestoncowboy]

In some guns you have to seat and crimp in seperate stages because of the amount of crimp (460 smith, 500 smith...anything fired from a 329pd) . In a revolver if you arent buckling the case then you arent over crimping, especially with the jacketed xtp. The lighter the gun the more crimp you will likely need to stop bullet creep. Too much will shorten the life of the brass but otherwise I wouldn't worry.

 

[joneb]

For my heavy 357 mag and 44 mag loads with bullets on the heavy side I seat and roll crimp into the cannelure where there is about 1/4 of the cannelure showing, I then use a lee collet crimp die to keep the bullet from moving from recoil in my revolvers. This is the only way I have found to keep the COL of the unfired rounds from lengthening in the cylinder.
I have heard that pine tar has been used as a moisture seal and that it increases case tension on the bullet, I have not tried that yet.

 

[IlikeSA]

I crimp my 357 loads about like that. The only thing I crimp lighter are my wadcutter loads, because it doesn't need a heavier crimp and it works the case mouth less. I find that the heavier crimp is needed on some magnum powders to build pressure for a complete powder burn and get the most out of the load.

 

[243winxb]

To much crimp. Neck tension keeps bullets from moving , for the most part.

Your want roll crimp, not a squashed crimp.

My 357 Starline Brass loaded & fired 8 times. RCBS dies used.

My S&W 337 PD 38+P , a 10 oz revolver, doesnt jump crimp. Bullets are held by neck tension.

 

[Walkalong]

It's not unusual for some of the crimp to remain after being fired.

Do you have a good pic of a round before it is fired to show the crimp?

Anything like this?

 

[Jonesy814]

I use Lee dies and yes that's what the instructions say, but I think that creates too much roll crimp. When I set mine with a full turn of crimp it actually pulls\pushed the bullet down into the case about .005. I find about a 3/4 turn creates a nice fairly heavy crimp

 

[mrawesome22-250]

Use just enough crimp so that the bullets in the cylinder do not pull out under recoil. Anything more is not needed and just works the brass more.

 

[Obturation]

I'm guilty of heavy crimping. To me it's fine because then i know nothing is moving until the primer is struck. I'm one who prefers the lee factory crimp dies, when i have a tube full of 400+ grain 45-70s over a stiff charge i don't worry about set back and my heavy 454 casull loads don't get any longer under recoil - i have left a couple in the cylinder for 20 or so rounds and checked length. It is less crucial in 357 mag but the brass is cheap enough and common i don't care. So i say crimp how you like and see how long the brass lasts. I have 357 cases that i have loaded 12+ times crimped like that, you can always back down a bit if case life suffers but if i get 10 loadings on a case it doesn't owe me a thing. Others may expect more.

 

[sparkyv]

Use just enough crimp so that the bullets in the cylinder do not pull out under recoil. Anything more is not needed and just works the brass more.

^^^This^^^ When working up a new load, I leave one round unfired in the cylinder and check COAL after to verify if crimp was satisfactory.

 

[joneb]

For my heavy 357 mag and 44 mag loads with bullets on the heavy side I seat and roll crimp into the cannelure where there is about 1/4 of the cannelure showing, I then use a lee collet crimp die to keep the bullet from moving from recoil in my revolvers. This is the only way I have found to keep the COL of the unfired rounds from lengthening in the cylinder.
I have heard that pine tar has been used as a moisture seal and that it increases case tension on the bullet, I have not tried that yet.

I should be more clear, the Lee die I use is not a Lee FCD it is a collet crimp only crimp die. This is the same design Lee uses for it's rifle crimp.

 

[Rod47]

I have seen casings with that same type of crimp crack or seperate on the crimp line. I wouldn't expect your cases to hold up very long.

 

[Walkalong]

I should be more clear, the Lee die I use is not a Lee FCD it is a collet crimp only crimp die. This is the same design Lee uses for it's rifle crimp.

That's what the OPs crimp looked like, couldn't be sure though. Would still like to see a pic of his crimp.

 

[Lee Q. Loader]

That's what the OPs crimp looked like, couldn't be sure though. Would still like to see a pic of his crimp.

I'm not sure how you all take such great close ups. Here's the best I can do. I don't have any XTP's loaded. This is a Sierra 158 soft point, but it's the same crimp.

 

[Walkalong]

I would not call that heavy, and if you are using the Lee rifle type collet crimp you need to get the cannelure deeper in the case. With a regular roll crimp the case neck should 'roll" into the middle (deepest part) of the cannelure. This is why I trim revolver cases, for consistent crimps.

 

[243winxb]

Right one-squashed OP photos.

 

[Lee Q. Loader]

you need to get the cannelure deeper in the case

This is a common problem for me. I seat and crimp in 2 steps. When I seat the bullet and inspect, it looks almost like it's too deep. Then after crimping it looks like my pic above.

 

[murf]

it is easier to see the crimp using a 10x, or finer, loupe. my loupe is 14x and reveals a lot. also, use a strong light with the loupe.

i'll not add advise, since it would just be repetition.

luck,

murf

 

[Walkalong]

it is easier to see the crimp using a 10x, or finer, loupe.

I have some on my reloading bench, my eyes need them now more than ever.

 

[murf]

I have some on my reloading bench, my eyes need them now more than ever.

I use one of these: https://www.walmart.com/ip/4-Lens-H...0000003066&wl14=headband magnifier 5x&veh=sem every time I reload. the 14x loupe is for checking crimp, checking the forcing cone and muzzle end of the barrel for leading/copper, etc.

murf

 

[Walkalong]

This is a lens from an old Projector used for slides (Yep, I'm old)

 

[mdi]

When I started reloading I used the "turns" to determine a crimp.But "one full turn" sounds excessive to me, I'd try 1/2 turn or just go by what the crimp looks like on a finished cartridge. Some of my handloads work better with a heavy crimp, mainly my Magnum loads with slower powders (I use a lot of 2400 and WC820)