Question on crimping

[JDMAG]

I am having trouble with the crimp on my & mag dies. I thought I was doing it right so I followed the instructions and I was doing it correctly. This brass has been fired 3-4 times and when I try to adjust the crimp even if I only turn the die 1/16th of a turn or less, the bullet remains loose until I finally crush the cartridge. any suggestions? This is Federal Brass. i have just ordered some new winchester brass and a lee factory crimp die from Midway. The first couple of times the bullets were fine, and still on some of the reloads are tight.

 

[JD338]

What caliber are you loading?
Who is the die manufacture?

JD338

 

[JDMAG]

7 mm mag RCBS sb die set group A P/N 13603

 

[JD338]

JDMAG,

Federal Nickel plated brass?

Try some R-P brass and see if it corrects the problem.


JD338

 

[JDMAG]

it's not nickle plated, but I'll try some remington brass.
Thanks JD!
JD

 

[JDMAG]

That seems to have worked!
Thanks

 

[DrMike]

Are the cases trimmed before sizing? Check the length of the neck and the OAL of the case. It sounds as if your necks may be stretched, thus contacting the roll crimping ridge before the die cartridge is fully inserted into the die. Also, are you crimping into the cannelure?

 

[rick smith]

The bullet should not be loose before you apply a crimp and certainly not after. Are you seating and crimping in one step or two? Are all your cases trimmed to the same length? Have you measured the OAL of a case before and after sizing?Rick.

 

[FOTIS]

The only cartridges I crimp are:

handguns and levers.

Not even the 378 416 bees....

 

[DrMike]

I have used Lee crimp dies, but they are probably not necessary. In general, I agree with POP. Certainly, in load development I would not crimp.

 

[JDMAG]

The AOL of the F C cases that will not crimp or hold a bullet is 2.5025. The
R P brass that does hold a bullet, is 2.4990. That is the only difference I can find. The neck length is .2330on the F C and .2520 on the R P
These measurements seem to be with in tolerance of the spec's for the cartridge in my nosler #4 manual. These measurements were taken after
Sizeing.
Dr.Mike, These are AB's and there is no canalure.
Thanks,
JDMAG

 

[JD338]

The only cartridges I crimp are:

handguns and levers.

Not even the 378 416 bees....

+1

I only crimp 44 Mag and 45 ACP. Even my 338 RUM doesn't need a crimp.

JD338

 

[JDMAG]

The only cartridges I crimp are:

handguns and levers.

Not even the 378 416 bees....

+1

I only crimp 44 Mag and 45 ACP. Even my 338 RUM doesn't need a crimp.

JD338

I agree with that which is probably why this is so puzzeling to me. Why are my bullets loose?

 

[BK]

Are you seating and crimping in one step or two?

The crimp is not causing the problem is it?

As noted above I don't crimp anything but handgun rounds. Maybe .30-30s, but it's been so long since I've loaded any, I don't remember.

 

[JDMAG]

1 step for seating and crimping. Iwasn't crimping these until I noticed that some of the bullets were loose.and then when I tried to adjust, I got nowhere. other than some funky lookin cartridges. :shock:

 

[BK]

Try screwing your seater die OUT some and then screw the seater stem down to make up for the die moving up. I bet you are over crimping.

 

[JDMAG]

but even when I over crimped and crushed the case, the bullet was still loose.

 

[BK]

I got that, but by over crimping, you are messing up the neck tension of the case. When you seat the bullet, you should not be able to move it with your fingers.

 

[JDMAG]

I understand what you are saying now. The way I set the crimp up was to seat a bullet to my seating depth, then I backed the seater out, and raised the cartridge into the press. then screwed the die don until I could feel it hit the cartridge. Then I lowered the cartridge and turned the die 1/8th of a turn (per instructions) and tried to crimp the bullet. no dice so I backed up and tried again. I did this until the case got crushed. Am I doing something wrong? Am I starting out with the die too deep in the press? I shouldn't be able to screw it down any further with a cartridge raised into the press should I?

 

[rick smith]

If the bullets are loose after being seated in a sized case then either the neck isn't being sized enough or the expander ball is too large for that lot of brass. Also trying to crimp a non-cannelured bullet can cause it's own set of problems. If you have a ball micrometer measure the neck wall thickness. Or measure the OD of the neck before and after sizing do that with and without the expander ball in the die. Also measure the OD of the expander ball.

BK, if one plans to crimp bullets in place with a roll crimp, all the cases should be trimmed to the same length. For better uniformity, seat and crimp in two steps. I have tried it both ways and better accuracy, for me, has been with the two step method. For the loads that I plan to roll crimp or taper crimp I will buy a seperate die for crimping. JDMAG said his bullets were loose after being seated I think he was trying to hold them in place with a roll crimp. You will not see the same type of crimp on non-cannelured bullets and guess he moved the die down more and crushed the shoulder/neck area.Rick.