9mm Major Bullet/crimp Problem

[lcs]

Equipment: Lee dies (4 set), and Dillon 550b.

This problem is NOT specfic to any brass. It happens to all brands.

This problem is random.

Crimp is .378 in most cases. Bullets are .356 and different types. (Zero or Berry Plated)

Every once in a while (no load count is the same) I find a bullet that measures the correct crimp, but the bullet will actually turn freely in the shell case after being crimped.

I pull the bullet and it appears normal. A slight crimp line around the bullet.

Is this normal to have this occur in about two out of a hundred rounds or I am doing something wrong?

Apreciate any reloader GURU help.

Thanks

[Harmon]

factory crimp die is distorting the bullet(the brass springs back while the lead core of the bullet stays compressed) when it sizes the case.

replace with a dillon brand die and i bet the problem will dissappear

[lcs]

factory crimp die is distorting the bullet(the brass springs back while the lead core of the bullet stays compressed) when it sizes the case.

replace with a dillon brand die and i bet the problem will dissappear

I think you were close (the lead core was staying compressed on the bullets I pulled). I rechecked all the dies and the powder die was set to low causing the brass to buldge and then the crimp was too tight.

Once I adjusted those two dies, I ran 100 or so and no problems. I will keep your idea in mind if I see the problem again.

Thanks for the input.

[Harmon]

either/or, just hope you get things working right.

I know remington golden saber bullets dont work well with FCD

Harmon

[DaG]

I had the same problem once and figured out I had not switched out my dies from 38 super to 9. straight wall to taper wall. 9's should look like little coke bottles.

DaG

[Patrick Sweeney]

Repeat after Me: "Crimp is not there to keep bullets tight in the case. Crimp is there to get the rim out of the way in feeding. Bullets stay in the case due to neck tension, which is controlled/determined by the diameter of the powder drop tube."

Check the powder drop tube. The largest it can be and do its job is on the order of .353" On some cartridges that use 9mm bullets, I run the tube as small as .349"

[BSeevers]

Another test is take a loaded round, measure its OAL, push it hard nose first into your bench, measure OAL.

[lcs]

Repeat after Me: \"Crimp is not there to keep bullets tight in the case. Crimp is there to get the rim out of the way in feeding. Bullets stay in the case due to neck tension, which is controlled/determined by the diameter of the powder drop tube.\"

Check the powder drop tube. The largest it can be and do its job is on the order of .353\" On some cartridges that use 9mm bullets, I run the tube as small as .349\"

How do you run the tube as small as .349 ?

[.40AET]

How do you run the tube as small as .349 ?

Take the tube out of the powder die and put it in a drill press or sand/polish it by hand until it is the correct diameter. They need polishing anyway so now you can do both.

Edited November 20, 2006 by .40AET

[lcs]

How do you run the tube as small as .349 ?

Take the tube out of the powder die and put it in a drill press or sand/polish it by hand until it is the correct diameter. They need polishing anyway so now you can do both.

Thanks.

[Patrick Sweeney]

That, or a lathe. The first time I cleaned up a drop tube, I was using a Clausing 1300, a production turret lathe that sold then for something like $20,000. the irony, using a lathe more expensive than my truck, to clean up a five-dollar part.

Use some sort of hard backer, if you use abrasive cloth, to keep the surface concentric, square and even.

[Chris Keen]

Saw the exact same thing when loading Production 9mm. I assume you are using once-fired brass ??? Whne you find one that is too loose .... toss it.

I have better things to do with my time than try and figure out why 1 or 2 pieces of once-fired 9mm out of 100 are giving me fits.

I don't think it's your eqpt. Larry.

[George]

Crimp is a poor term for flattening the case mouth bell out so the case wall meets the bullet flush again. Actually indenting the bullet with some reall "crimp" is not a good idea in most cases (there are reasons for it in revolvers and when loading for tube magazine rifles like the 30-30 round is used in).

You are very possibly squeezing the bullet too much and it ain't springin' back.

Plain and simple solution if this is the case, Don't crimp, just restore the case mouth to flat against the bullet. If the bullets won't stay in place by just flattening the bell out, the problem is in your sizing die. Specifically the expander ball is too big and the case mouth is getting stretched out. This fit is what is supposed to hold the bullet in place, not after the fact squeezing.

Crimping is a band-aid to the expander ball being outa' whack for your brass/bullet combo and if a case won't hold a bullet from just sizing, you need to fix the problem, not hide it with a FCD.

Another thought is "are you using mixed lot brass"? If so, it could be case wall thickness variance causing this.