Factory Crimp, tell me how this looks!

Status
Not open for further replies.
P

Philippe

Member
Joined
Jul 10, 2011
Messages
81
Something just looks off to me. These are .357 mag, mixed brass and montana gold 125gr jhp's. Im using a Lee factory crimp die. Any suggestions?
357mag2jpg.jpg
 
I guess its the uneven parts of the brass when i crimp them, im still not to use to using this factory crimp die, i use to use the regular rcbs die and decided to give the factory crimp die a try. I know they function because i shot some like this over the weekend lol.
 
Looks good. Personally I think the "factory crimp" die is a sales gimmick and doesn't do anything that you can't accomplish with "standard" dies. I can see a lot of variation in case lengths in your photo. It is almost impossible to get consistent crimps when the cases are all different lengths. I flare very gently and use taper crimps for everything. The brass lasts much longer.
 
Last edited:
Those ones you are looking at in the pic are 125gr montana golds sitting over 10.0 grains of Power Pistol, small pistol primers, mixed range brass, seated to 1.580
 
The crimp looks way off to me. That's what my first couple rounds looked like when I overcrimped with a TAPER crimp die. My Lee .357 seater die puts a nice smooth roll on the mouth. I assume the FCD does, too, but I have hardly used it.

Just a guess, but maybe the crimp groove on those bullets is too shallow for the amount of crimp you're trying to get.
 
Last edited:
I agree GLOOB, the cannelure is extremely shallow, which does not allow a nice roll crimp. Not really a cannelure, just some roll marks on the bullet. I would taper crimp those bullets, although the OP's crimps are pretty good for what he had to work with.
 
The flat ring at the top of the roll crimp, means you are over crimping, and pushing the case beyond the crimp ring in the die. Back the die off 1/8 turn at a time until you get a rounded roll crimp without the flat ring at the case mouth.
 
The Lee FCD is putting the roll crimp on them because the .357 mag is a revolver load.

The Lee FCD for revolver rounds applies a roll crimp, and the FCD for auto-loader rounds applies a taper crimp.

You will have to adjust the level of the crimp (light/medium/heavy).
 
The "roll" part of the crimp looks almost right, if it were to continue a few thousandths more. The crimp ring above that doesn't look right at all.

Like the other guys said, 357 mag gets a roll crimp, not a taper crimp.
 
Ok, when I back off on this die it seems as if I am not getting a good crimp, I am about to go back to the rcbs dies.....
 
Am I seeing a ridge above the curved part of the crimp? Looks like the rounds are crimped too much and is leaving a ridge, rather than a smoothe curve.
 
Looks like the LFCD is turned too far in.

The book calls for snugging to the case, then 1/2 turn (light) to 1 full turn (heavy) more.

If you're crimping slow powder Big Dog loads then you want a roll crimp. It helps powder combustion & prevent the bullets from jumping crimp under heavy recoil.

The LFCD is just to snug down the mouth & remove the bell. Those are for lower power target loads with faster powder.
 
I have gotten similar looking crimps using the lee factory crimp die.... I fillowed the instructions and did a full turn for a heavy crimp.... These are for loads that call for heavy crimps.... Now I am worried. Is there any danger in setting the crimp like above or will it just lower the case life?
 
The profile of the Montana Gold bullet must be different than the Speer. Looks to me like they should be seated to a little shorter COL. The crimp looks fine, but it should go into the cannelure. That's what it's for.
 
A proper taper crimp die cannot put that ridge on the brass. That ridge is from a roll crimp where there is no more cannelure for the crimp to go in. That same adjustment would work with a lead crimp groove or a good deep cannelure, but it is more crimp than needed with that poor cannelure. It will not hurt a thing except case life, and even then the cases will last quite a while. Back off on the roll crimp a little, or get a taper crimp die like I linked to. The Redding is superior, but double the cost. Polish the Lee if you get it.
 
Thanks for the info guys, I am going to look into that other die, i ran another small batch lastnight and adjusted the die, I'll post a pic when I get home to see what ya think.
 
Status
Not open for further replies.
Back
Top