over crimping

jartzh · May 5, 2009, 09:50 AM

I am loading 38 spl and 357 mags and while moving the dies for each case I notice some of the crimping is slightly deforming the cases. You can see a slight image of the bullet in the case. Is there a such thing as "over crimped".
What is the effect of crimping except to keep the bullet from falling out of the case?

rjrivero · May 5, 2009, 10:12 AM

The crimp on the round is to keep the round from falling out under recoil. In the revolvers, I tend to go for the LEAST crimp I can get. My thought is that if I don't over work the brass from sizing, to belling, to crimping, it will last longer.

I'm sure there will be someone with more experience who will chime in.

jartzh · May 5, 2009, 10:15 AM

My major concern is safety. Are these safe to shoot in my revolver? I certainly didnt plan on doing this and wont in the future (unless its better).

rjrivero · May 5, 2009, 10:20 AM

Good question. If you are near MAXIMUM loads, you have a genuine concern for over pressure. What is your load recipe?

jartzh · May 5, 2009, 10:37 AM

I am shooting 38 spl loads in my 357 so I am nowhere near the max load for my pistol normally. I am using 4.1 grains vs 7.5 grains if it was a 357 load.

rjrivero · May 5, 2009, 11:45 AM

I would have NO hesitation to shoot those rounds, personally. Then adjust the dies on the next go round. I'm a bit cavalier though.

howlnmad · May 5, 2009, 11:56 AM

You didn't say if it was an image of the base of the bullet all the way around the case or if it was a crush caused by over crimping. If the first is the case, that is normal due to undersizing by the sizing die. If the later is the case... you have over crimped and made fodder for the scrap bucket. You must crimp revolver rounds to keep the bullet from walking out of the casing caused by recoil. You don't have to go overboard, just enough to hold it in place.

jamaica · May 5, 2009, 12:51 PM

When you resize your casings the diameter is reduced. When you seat a bullet the brass is expanded a small amount to the depth that the bullet goes into the casing. Sometimes you can actually see a slight bulge where the base of the bullet is. This is normal and no safety issue.

38 and 357 dies have a roll crimping ring in them. You need to crimp enough to bring the bell back in snug to the bullet, and if you have a crimp ring on the bullet give the brass a bit of a roll into the ring. It doesn't take much. The way you adjust the crimp is by turning the die in or out until the amount of crimp is right.

Over crimping will sometimes cause buckled brass in the area just below the crimp. This kind of a bulge is not a good thing. It can loosen the bullet in the casing, and also prevent the casing from chambering.
You can shoot these if they will chamber.

Let us know more about just exactly where you see the bulge?

jartzh · May 5, 2009, 02:14 PM

I can just see the image of the bullet in the case. Its faint on most and on some I can see it and others I cant.
I did not crinkle the case (except for a couple that I did discard).

I will try the chambering test. As I gather if it chambers then it will be ok to fire.

Thanks, its great having some experts to keep me from blowing my head off.

Hook686 · May 5, 2009, 02:27 PM

I sounds to me as though you have resized the case, belled the mouth, inserted a bullet (that is just a tad larger than the shell case), then crimped the belled mouth.

Are you using lead bullets ?

This sounds pretty normal to me ... to see a slight 'outline' of the bullet in the shell case below the crimped neck of the case. Is the appearance linear (by that I mean not appearing tilted) ? I once had a few bullets seat slightly askewed when loading at the range with a Lyman 310 Tong Tool ... the neck was not belled enough and the bullet seated with a little lead being scraped off one side. I loaded a couple that the 'image' in the brass you refer to looked canted slightly, until I adjusted the die.

If this is what you are describing, I can only say I shot the rounds without a problem.

SwampYankee · May 5, 2009, 04:29 PM

This used to happen to me all the time when I crimped and seated in the same operation. If I seat every bullet and then go onto crimping, it does not happen. Consequently, I never seat and crimp at the same time. I also got a lot of bullets that bulged the cases if I crimped and seated at the same time, and those cartridges won't fit the chamber.

Quote:

This sounds pretty normal to me ... to see a slight 'outline' of the bullet in the shell case below the crimped neck of the case.

Once again, if you seat and crimp in separate operations, it will never happen. Check out any commercial cartridge, you'll never see that outline. Just make sure you also bell the mouth a tad. If not, the same thing will happen. If it chambers, you will be fine but a number of those will probably not chamber and you will need to pull them.

drail · May 5, 2009, 07:24 PM

If you can see the base of the bullet slightly bulging the case then you have good case neck tension. This will hold the bullet in place so that it won't setback from repeated chambering or pull under recoil in a revolver much better than trying to hold it with just a crimp. If your expander die opens the mouth of the case more than just a little under your bullet's diameter the bullet is not being held tightly enough. If neck tension is too light no amount of crimp will stop it from moving. I have turned down the expander plugs in several of my die sets until I can see just that bullet base bulge. 1.5 to 2 thousandths smaller than bullet diameter is perfect. And seating and crimping in two operations is a good habit to follow.

May 5, 2009, 09:50 AM	#1
jartzh Junior Member Join Date: May 5, 2009 Location: Texas Posts: 8	over crimping I am loading 38 spl and 357 mags and while moving the dies for each case I notice some of the crimping is slightly deforming the cases. You can see a slight image of the bullet in the case. Is there a such thing as "over crimped". What is the effect of crimping except to keep the bullet from falling out of the case?

May 5, 2009, 10:12 AM	#2
rjrivero Senior Member Join Date: November 17, 2008 Location: NW Ohio Posts: 1,399	Crimp.... The crimp on the round is to keep the round from falling out under recoil. In the revolvers, I tend to go for the LEAST crimp I can get. My thought is that if I don't over work the brass from sizing, to belling, to crimping, it will last longer. I'm sure there will be someone with more experience who will chime in.

May 5, 2009, 02:27 PM	#10
Hook686 Senior Member Join Date: May 22, 2005 Location: USA The Great State of California Posts: 2,090	I sounds to me as though you have resized the case, belled the mouth, inserted a bullet (that is just a tad larger than the shell case), then crimped the belled mouth. Are you using lead bullets ? This sounds pretty normal to me ... to see a slight 'outline' of the bullet in the shell case below the crimped neck of the case. Is the appearance linear (by that I mean not appearing tilted) ? I once had a few bullets seat slightly askewed when loading at the range with a Lyman 310 Tong Tool ... the neck was not belled enough and the bullet seated with a little lead being scraped off one side. I loaded a couple that the 'image' in the brass you refer to looked canted slightly, until I adjusted the die. If this is what you are describing, I can only say I shot the rounds without a problem. __________________ Hook686 When the number of people in institutions reaches 51%, we change sides.

May 5, 2009, 10:15 AM	#3
jartzh Junior Member Join Date: May 5, 2009 Location: Texas Posts: 8	My major concern is safety. Are these safe to shoot in my revolver? I certainly didnt plan on doing this and wont in the future (unless its better).

May 5, 2009, 10:20 AM	#4
rjrivero Senior Member Join Date: November 17, 2008 Location: NW Ohio Posts: 1,399	Good question. If you are near MAXIMUM loads, you have a genuine concern for over pressure. What is your load recipe?

May 5, 2009, 10:37 AM	#5
jartzh Junior Member Join Date: May 5, 2009 Location: Texas Posts: 8	I am shooting 38 spl loads in my 357 so I am nowhere near the max load for my pistol normally. I am using 4.1 grains vs 7.5 grains if it was a 357 load.

May 5, 2009, 11:45 AM	#6
rjrivero Senior Member Join Date: November 17, 2008 Location: NW Ohio Posts: 1,399	I would have NO hesitation to shoot those rounds, personally. Then adjust the dies on the next go round. I'm a bit cavalier though.

May 5, 2009, 11:56 AM	#7
howlnmad Senior Member Join Date: April 29, 2009 Location: Harriman Tn Posts: 424	You didn't say if it was an image of the base of the bullet all the way around the case or if it was a crush caused by over crimping. If the first is the case, that is normal due to undersizing by the sizing die. If the later is the case... you have over crimped and made fodder for the scrap bucket. You must crimp revolver rounds to keep the bullet from walking out of the casing caused by recoil. You don't have to go overboard, just enough to hold it in place.

May 5, 2009, 12:51 PM	#8
jamaica Senior Member Join Date: March 24, 2006 Location: Northern Utah Posts: 705	When you resize your casings the diameter is reduced. When you seat a bullet the brass is expanded a small amount to the depth that the bullet goes into the casing. Sometimes you can actually see a slight bulge where the base of the bullet is. This is normal and no safety issue. 38 and 357 dies have a roll crimping ring in them. You need to crimp enough to bring the bell back in snug to the bullet, and if you have a crimp ring on the bullet give the brass a bit of a roll into the ring. It doesn't take much. The way you adjust the crimp is by turning the die in or out until the amount of crimp is right. Over crimping will sometimes cause buckled brass in the area just below the crimp. This kind of a bulge is not a good thing. It can loosen the bullet in the casing, and also prevent the casing from chambering. You can shoot these if they will chamber. Let us know more about just exactly where you see the bulge?

May 5, 2009, 02:14 PM	#9
jartzh Junior Member Join Date: May 5, 2009 Location: Texas Posts: 8	I can just see the image of the bullet in the case. Its faint on most and on some I can see it and others I cant. I did not crinkle the case (except for a couple that I did discard). I will try the chambering test. As I gather if it chambers then it will be ok to fire. Thanks, its great having some experts to keep me from blowing my head off.

May 5, 2009, 07:24 PM	#12
drail Junior member Join Date: February 2, 2008 Posts: 3,150	If you can see the base of the bullet slightly bulging the case then you have good case neck tension. This will hold the bullet in place so that it won't setback from repeated chambering or pull under recoil in a revolver much better than trying to hold it with just a crimp. If your expander die opens the mouth of the case more than just a little under your bullet's diameter the bullet is not being held tightly enough. If neck tension is too light no amount of crimp will stop it from moving. I have turned down the expander plugs in several of my die sets until I can see just that bullet base bulge. 1.5 to 2 thousandths smaller than bullet diameter is perfect. And seating and crimping in two operations is a good habit to follow.