Cannelure and COAL question: picture included

SLT223

SLT223

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I just got started with my new Dillon 650. I'm in the process of setting up my seating and crimping dies. My Lyman #49 Manual calls for COAL of 1.590 for .357 Magnum with a 158gr LSW. I'm using Xtreme plated 158gr LSW's. When I seat them to COAL 1.590" the crimp occurs much toward the bottom of the cannelure. Is this correct? Should I be at all concerned about where crimp occurs within the cannelure band? I have never seen factory rounds showing this much cannelure, which is why I'm asking my question. It just doesn't look right to me.

Also, having measured some factory Federal 158gr semi jacketed flat nose rounds I found COAL varied from 1.578 to 1.583. Is that really acceptable?

 
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The OAL listed in any manual is not the OAL you must use when making your ammo, it's only reporting the OAL they used when developing the load data. Unless you use the same exact brass, trimmed to the same exact length and the same exact bullet they used the OAL they list is useless to you.

With revolver ammo you should always use the crimp groove supplies by the manufacturer. It is the correct crimp position on that bullet. Use the crimp provided by the manufacturer and you are doing it correctly...
 
Keep in mind that 1.590 inch in your Lyman manual is the Maximum Overall Length per the SAAMI specification. If you start poking around in the Speer, Lee, Hodgdon, Accurate, Alliant, and other reloading resources you'll find that the OAL length for the 357 Magnum with a 158 grain jacketed bullet can range from 1.570 up to 1.620. I would suggest that you look at the load data for the powder you are using from the powder manufacturer and see what they are listing for an overall length. If it's a bit shorter I see no problem with using that length even if you are loading right at the powder manufacturers maximum charge.

BTW, you will probably notice that the powder manufacturers load data is significantly lighter that Lyman's data. I suspect that reason for that difference is that Lyman's data is rather dated and was generated using the Copper Crusher method for determining pressure. More recent data generated using piezo electric pressure testing has shown that the older method didn't have the resolution needed to measure brief spikes in pressure. As a result of this difference newer data is typically 1 or 2 grains lighter in the charge level to insure that those brief spikes don't exceed the SAAMI maximum. Basically if I see CUP listed in the Lyman manual I treat that data as reference only material and look for a more modern data set that was tested using PSI.
 
Thanks guys, appreciated. I knew it didn't look right...it's the only round I've seen like that. I'm going to load Hogdon Clays for .357 Mag and 44 Mag, but not until I get the dummy rounds right. I think this makes more sense:
About 2/3's up the cannelure
 
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COAL in a revolver really isn't relevant. Load to the crimp groove, crimp, done. The only time this does NOT apply is loading long bullets for a given revolver & the crimp groove can not be used.
 
SLT223,

Too bad you didn't get started on a single-stage press until you got a bit of experience and understood what you are doing. You don't understand what the 1.592" COL means. This is the SAAMI maximum length to assure the cartridges will function in any standard firearm chambered for the cartridge. It is not a specification! Most bullets, when seated to the center of the cannellure, will be shorter than this. This is normal and correct. Reloading manual COL lengths listed under data for specific bullets mean nothing more that that that bullet, seated to the cannelure, will result in approximately that length. It is a result, not a specification!

In revolvers you can load so that the bullet rests just short of the face of the cylinder, but few bullets will have a cannellure at that point to crimp in.

It isn't my intent to beat up on you or insult you, but to get your attention! The very first step before attempting any reloading is to buy a good reloading manual, read it, several times if necessary until you understand the basics. Then, whenever you run into something you don't understand, stop, go back to the manual, and search until you find the answer.

Something you may not understand about internet forums, not everyone who posts on any subject necessarily has any practical knowledge about the subject upon which they are expounding! From what I read there are quite a few who are more than willing to give advice when they have, obviously from what they write, have never loaded a cartridge in their life! This applies to this forum as well as others. Go to the powder and bullet manufacturers manuals for information, they have a vested interest in providing accurate, safe information. They can be sued!!! Anonymous posters on internet forums cannot. It is your safety that is at stake, remember that every time you pull that press handle.

The ones who understand what I am saying will probably cheer, where the ones who fit the description will probably be posting trying to defend themselves, even though they were not mentioned!!!!
 
In addition to the above, cannelures are located approximately where they're supposed to be for the most common use of that bullet. Doesn't mean it's in the correct place for your usage. Remember, the purpose of a cannelure in a revolver bullet is to prevent the bullet from being pulled forward in recoil.
 
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SLT223 said:
Thanks guys, appreciated. I knew it didn't look right...it's the only round I've seen like that. I'm going to load Hogdon Clays for .357 Mag and 44 Mag, but not until I get the dummy rounds right.
Click to expand...
Is there a reason why you are going to use Clays? Magnum ammo is usually associated with the slowest of the handgun powders but Clays is one of the fastest powders available. Pressures are going to top out well before velocities get anywhere near where a Magnum load should be. I have used Clays for .38 Special and 45 auto ammo but nothing high pressure.

NOTE:
* If it's the only powder you have of course that's what you use.
* If you are looking to load 38 Special loads in .357 Magnum brass I understand.
* If you want "real" magnum ammo I suggest using a much slower powder.
Those powders are:
Alliant 2400 - (very popular and versatile)
W296 & H110 - (shouldn't be downloaded)
IMR-4227 - (especially good w/heavy bullets in the .44 Magnum)
Alliant Power Pro 300-MP
Accurate #9
Accurate 4100
Ramshot Enforcer

There are slightly faster powders that will also work almost as well but those are the powders most associated with full power Magnum handgun ammo.
 
Crimp it in the center of the cannelure. Forget the published COL. Start low/work up.
 
ArchAngelCD said:
Is there a reason why you are going to use Clays? Magnum ammo is usually associated with the slowest of the handgun powders but Clays is one of the fastest powders available. Pressures are going to top out well before velocities get anywhere near where a Magnum load should be. I have used Clays for .38 Special and 45 auto ammo but nothing high pressure.
Click to expand...

Yes. I have a free pound of Clays, and at only four grains (max 4.6) it seems to be extremely economical for plinking loads.
 
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