To crimp or not

[johnnyreb65]

Going to start loading .357. reloading manual says to crimp some people I talked to do, some don't. So do I crimp or not..Also I was looking at a set of Lee dies at Bass Pro but they only have the 3 die set. I've got the Lee factory crimp die for 9mm, can I use it to crimp .357 they're real close.

 

[mlehtovaara]

Crimping is important for full house magnum loads! A it keeps the bullets from moving in or outta the cases under the recoil of the gun. B it allows the full power heavier loads to fully ignite and not leave a ton of unburned powder spewing from the gun or messing up the action.

You need a roll crimp which will roll the case mouth into the cannelure of the bullets you will be loading.

 

[pilon]

X2
Crimping is important but sure does shorten case life.

 

[sunray]

"...can I use it..." Nope. Close doesn't count. Without looking, I suspect the Lee dies will roll crimp with no fuss. A crimp is only needed for hot .357 loads. Not needed at all if you plan on loading .38 target loads in the .357 case.

 

[H4831]

Any good, standard three die pistol set will crimp your 357. Don't crimp any harder than just necessary to keep the bullets from pushing out and stopping the cylinder from turning. Also, to keep case life as long as possible, flare the mouth the smallest bit you can, in order to get the bullet seated. Under those two terms, case life is actually very long.

 

[johnnyreb65]

Any good, standard three die pistol set will crimp your 357. Don't crimp any harder than just necessary to keep the bullets from pushing out and stopping the cylinder from turning. Also, to keep case life as long as possible, flare the mouth the smallest bit you can, in order to get the bullet seated. Under those two terms, case life is actually very long.

So the standard Lee dies will roll crimp? Now I'm getting confused, if the 3 die set will crimp, then what's all the fuss about Lee factory crimp dies.

 

[daBear]

Factory crimp dies will post load resize the case to proper spec and can also increase the amount of crimp available versus the standard die. New loaders often dont set the crimp right and end up with a bulge at the crimp which makes it difficult to load into the cylinder. Common problem that will only be learned thru experience. The Lee FCD die restores the loaded round to spec, ensuring that each round will chamber without any difficulty. . On another note, be very careful crimping if you are using plated bullets. Crimping can actually cut thru the surface of the plating and result in fragmenting upon firing. Finally, the 9mm die provides a taper crimp and you need a roll crimp. Forget about even trying the 9mm FCD.
dB

 

[NorthernCX]

The difference is the type of crimp. The 'factory crimp' puts a squeeze from outside the case all the way around the bullet. This will also put a cannelure onto plain bullet if it doesn't have one. It also will NEVER buckle a case.

The roll crimp is just that; it 'rolls' the lip of the case neck into a cannelure on a bullet. Seat the die in too far and you will buckle the neck (or the case if you're loading pistol ammo), and give you all kinds of grief when you try to load/chamber the round. ALL Lee bullet seating dies will roll crimp; read the instructions and they tell you how. The same die, set differently, only seats the bullet and lets you use the Factory Crimp Die. You cannot roll crimp a jacketed bullet without a cannelure; that's the biggest reason people go with the factory crimp; it's simple, works with ANY bullet, and makes seating depth a little less critical because it provides a consistent starting pressure to get the bullet moving.

 

[johnnyreb65]

The difference is the type of crimp. The 'factory crimp' puts a squeeze from outside the case all the way around the bullet. This will also put a cannelure onto plain bullet if it doesn't have one. It also will NEVER buckle a case.

The roll crimp is just that; it 'rolls' the lip of the case neck into a cannelure on a bullet. Seat the die in too far and you will buckle the neck (or the case if you're loading pistol ammo), and give you all kinds of grief when you try to load/chamber the round. ALL Lee bullet seating dies will roll crimp; read the instructions and they tell you how. The same die, set differently, only seats the bullet and lets you use the Factory Crimp Die. You cannot roll crimp a jacketed bullet without a cannelure; that's the biggest reason people go with the factory crimp; it's simple, works with ANY bullet, and makes seating depth a little less critical because it provides a consistent starting pressure to get the bullet moving.

I was talking to a buddy of mine who was saying that the problem with the factory crimp, and crimping in general, is that unless the cases are the exact same length each shot will have diferent pressures. Is he on to something or just palin nuts?

 

[Boomer]

I was talking to a buddy of mine who was saying that the problem with the factory crimp, and crimping in general, is that unless the cases are the exact same length each shot will have diferent pressures. Is he on to something or just palin nuts?

While this is correct in theory, in practical application with a revolver it makes no difference. If you are shooting cast 158 gr bullets, chances are some of them weigh as much as 160-165 grs and some weigh as little as 150-155 grs. That has a much greater impact on pressure, on the uniformity of velocity, and on the shape and size of your group than does the fraction of an inch in case length.

It's a good practice to proceed carefully when loading maximum loads in handgun cartridges. This pertains particularly to thrown charges in small capacity cases when loading to maximum pressure. IMHO this is a bad idea, and every single thrown charge should be checked on a scale to ensure uniformity. If one bullet is a bit heavier than you expect for instance, you might find that you have an extraction problem. When working up loads, it is worthwhile to segregate your test bullets by weight so that you can see the true effect of an increase in propellant. Thus, when your maximum load has been determined with no extraction problems and a uniform bullet weight, a working load a full grain less than your maximum load will insure that you will not experience sticky extraction should you run into a few heavy, out of spec bullets. You could if you were patient enough, segregate all of your bullets by weight and load them accordingly, with a lighter powder charge for heavy bullets, but that is a tedious exercise when handloading handgun ammo is most often considered a high volume operation. Jacketed bullets tend to be more uniform in weight than cast, but even so, when maximum loads are being used, I weigh each charge.

 

[H4831]

So the standard Lee dies will roll crimp? Now I'm getting confused, if the 3 die set will crimp, then what's all the fuss about Lee factory crimp dies.

When I started to reload for the 45-70, which actually, is just an over-grown 357, straight cases all pretty much the same, especially with cast bullets, I purchased a 3 die Lee set, the first Lee dies I had ever had. Everybody told me to get a Lee factory crimp die, so I did.
I gave the factory crimp die a real good try out, decided it took more work, but actually didn't crimp as well as the standard seating die did, so I put aside the Lee factory crimp die and haven't used it since. The standard seating dies are doing an excellent job.
Over the years I have loaded a considerable amunt of cast bullets for the 38Spec/357, the 45ACP and the 44 magnum, all with using standard dies, usually RCBS, and never had a moments trouble of any kind.

 

[NorthernCX]

I was talking to a buddy of mine who was saying that the problem with the factory crimp, and crimping in general, is that unless the cases are the exact same length each shot will have diferent pressures. Is he on to something or just palin nuts?

Not so much. All my cases get checked for OAL, and trimmed to the same length. If they aren't stretched to where they need to be trimmed (I'm using a Lee trimmer/case length guage, but looking for another one since I'm starting to reload .45-70 and want to try Hornady Flex-Tip bullets), I don't worry about it. I'm only neck sizing, so as long as the bullet seats to the same depth, an extra thou or two of brass at the neck won't make a lick of difference. (I think- any other opinions?)

That being said, I'm only reloading for rifle, not handgun. Boomer's comments on bullet weights, if you're loading for pistol, are probably more relevant.

 

[acrashb]

you need a roll crimp.

Not really - while it's the default crimp type for .357, you can taper crimp just fine. I do.

 

[johnnyreb65]

Thanks for all your input guys

 

[Viper26]

Not really - while it's the default crimp type for .357, you can taper crimp just fine. I do.

+1
I've been taper crimping the 38/357 with no problems. For target loads all I'm really doing is straightening out the flair. Normal case to bullet friction does the rest. Maximum loads get a little more, but it's still a taper.

 

[corney]

Factory crimp dies will post load resize the case to proper spec and can also increase the amount of crimp available versus the standard die. New loaders often dont set the crimp right and end up with a bulge at the crimp which makes it difficult to load into the cylinder. Common problem that will only be learned thru experience. The Lee FCD die restores the loaded round to spec, ensuring that each round will chamber without any difficulty. . On another note, be very careful crimping if you are using plated bullets. Crimping can actually cut thru the surface of the plating and result in fragmenting upon firing. Finally, the 9mm die provides a taper crimp and you need a roll crimp. Forget about even trying the 9mm FCD.
dB

I am a little confused

"the 9mm die provides a taper crimp and you need a roll crimp. Forget about even trying the 9mm FCD."

Does the FCB provide a taper or roll crimp?

"The Lee FCD die restores the loaded round to spec, ensuring that each round will chamber without any difficulty"

Is this not a good thing?

I'm using 124 DBX heads and want to do the right thing.

 

[daBear]

Seems clear to me but here goes..

I am a little confused

"the 9mm die provides a taper crimp and you need a roll crimp. Forget about even trying the 9mm FCD."

Does the FCB provide a taper or roll crimp?

"The Lee FCD die restores the loaded round to spec, ensuring that each round will chamber without any difficulty"

Is this not a good thing?

I'm using 124 DBX heads and want to do the right thing.

The 9mm FCD provides a taper crimp, as is the case with other autos. Info is on the Lee site stating this. Revolver caliber FCD's use a roll crimp. Some manufacturers will offer dies with your choice of crimp but Lee does not.
If u do a bit of research, you will find that the 9mm case is not a straight walled case but has a slight taper. Check the dimensions of the 38/357 case and then check the 9mm dimensions. What you discover will answer the reason behind the statement advising against using the 9mm FCD for taper crimping 38/357. Although it may work as far as a crimp the case length difference would require modification of the die. Better off to spend $20 for the proper die.
Yes it is good that the FCD restores the case to spec providing it is used on the case it was intended for. Nothing is more frustrating than going to the range with your fresh off the press home loads, only to find that they wont chamber. The FCD rectifies this.
I am assuming that you are new to the reloading game so I suggest you actually do some research rather than just looking for answers on the forums. You will come across info that is valuable and you will learn far more than you set out to.

 

[hk33ka1]

I do use a Lee Factory Crimp die on my .357s just cus I have it. I would consider getting a seperate roll crimp die and doing it that way too.

I don't crimp .45-70 for my single shots, and to the guy wanting the case length gauge I have found my .45-70 cases don't grow but actually shrink or stay the same, so you might consider saving the $3 for the gauge as it won't even touch my cases.

 

[corney]

"What you discover will answer the reason behind the statement advising against using the 9mm FCD for taper crimping 38/357"

This is the part I didn't understand and I'm sorry it was not clear to me.

dabear I am actually not new to reloading and have spent a great deal of time reading all the manuals and books I could. I use this forum to continue to learn how to reload better as I have not learnt it all.

Thanks for clarifing that for me.

 

[daBear]

Corney, not meaning to offend so pls dont take my comments as such. The OP was stating that he was planning on using a 9mm FCD to crimp a 357 rd. Not knowing of the level of experience u had it was merely a statement advising to do a bit more research. Too often we see new loaders who have little if any experience simply posting a question without doing any research on their own or understanding why things are done that way. I am sure you have learned a lot over the years of both what to do as well as what not to do. I get concerned when I see postings from new loaders looking for recipes without them having the experience of knowing how to check loads etc. As you know, what works in one gun will not work in all guns and may be dangerous to others. Personally I have no problem in assisting a new loader but I would also like to see them do a little work on their own prior to posting.
Cheers
dB