reloading 9mm -- what am I doing wrong?

[beetle]

Hi There.

Been successfully reloading .45 for a few months now, getting good accuracy from my reloads.

Just tried doing a batch of 9mm and have some questions about how much crimp to apply. From what I've read on the net, the idea is to put just enough crimp to remove the bell. If I apply just a slight taper crimp, I can push the bullet in with my fingers.

If I apply just a little more crimp, I can still push the bullet in with my fingers, but the bullet itself is slightly indented. In other words, even with a medium crimp (enough to dent the bullet), I can still push the bullet in by hand.

If I apply a lot of crimp, this stops me from pressing the bullet in by hand, but obviously when I pull the bullet it will be heavily indented.

So what's the deal here? I would imagine that the right amount of crimp would be enough to stop me from pressing the bullet in by hand, yet not dent the bullet itself. But I can't seem to find this point. Even when the bullet is slightly indented, I can still push the bullet by hand (albeit with some force).

Any pointers would be greatly appreciated.

Montana Gold 124gr JHP
1.15 OAL
Misc brass

Thanks!

[huckberry668]

you're either not sizing the brass correctly or the sizing die is defective or the expander die stem is over sized. I'm assuming you're using a expander die to bell the mouth. even with no crimp you shouldn't push the bullet in by hand.

it could also be the bullets are under sized. give us more info

[Bill Steele]

Hi There.

Been successfully reloading .45 for a few months now, getting good accuracy from my reloads.

Just tried doing a batch of 9mm and have some questions about how much crimp to apply. From what I've read on the net, the idea is to put just enough crimp to remove the bell. If I apply just a slight taper crimp, I can push the bullet in with my fingers.

If I apply just a little more crimp, I can still push the bullet in with my fingers, but the bullet itself is slightly indented. In other words, even with a medium crimp (enough to dent the bullet), I can still push the bullet in by hand.

If I apply a lot of crimp, this stops me from pressing the bullet in by hand, but obviously when I pull the bullet it will be heavily indented.

So what's the deal here? I would imagine that the right amount of crimp would be enough to stop me from pressing the bullet in by hand, yet not dent the bullet itself. But I can't seem to find this point. Even when the bullet is slightly indented, I can still push the bullet by hand (albeit with some force).

Any pointers would be greatly appreciated.

Montana Gold 124gr JHP
1.15 OAL
Misc brass

Thanks!

MG 124's are .355" and pretty consistent in my experience, so it sounds like your sizing die is not sizing your cases down enough to give you good neck tension. The taper crimp is not for that purpose, it is only to take the belling out of the case.

It is possible, if you are using a single headstamp, that you have a brand of case that uses particularily thin brass, this can also play into the neck tension game.

If you are using mixed headstamps, using only the headstamps that emply the thickest brass, should improve the situtation.

If you are using Lee dies (their sizing dies tend to run a little loose), you can probably get better neck tension by buying a Hornaday or Redding sizer, they will probably be a thousandth or more smaller than the Lee.

Good luck.

[CSACANNONEER]

What kind of dies are you using? Are you using a separate crimp die? If so, what kind? Is your seating die adjusted properly? I really think this is probably the problem. Your seating die should seat the bullet and at the very end of the stroke, it should also slightly squeeze the case mouth to hold the bullet in better. My other guess would be that your brass is too thin for the sizing die you are using. If you are using a sizing die that is just a 1/4 a thousandth too big and brass that is a 1/4 thousandth thinner than "normal brass", you'll end up with the ID of your sized brass being 3/4 of a thousanth larger than it should be. That's almost a full thousandth of an inch and could be causing a problem similar to what you are describing. But, I would try adjusting the seating die first.

[beetle]

thanks for the help. I'm using Hornady dies. As the posters above state, I suspect it's a sizing problem. My brass measures about .378 after resizing. I don't think it's a seating problem because the bell is definately gone and I see a slight taper, but I don't think there is enough tension to hold the bullet in place.

Can someone measure what their case width is after resizing?

thanks!

[huckberry668]

yeah, .378" is way to big. mine sized cases measured .371" OD. the case wall measured between .012" to .014". which means your sized brass has a internal diameter of .354". 0.001" of tension isn't enough.

Edit: i think my RCBS sizing die sizes them a little on the small side. my loaded round have a bulge ring where the base of bullet is. i don't think it's a problem tho. however my friend's Dillon dies produces ammo w/o the bulge ring. we crimp to remove the bell only. so basically no crimp and I sort my brass by length .750" is what i pick to load my match ammo with.

Edited: .371" OD instead of .341"

[huckberry668]

are you using an expander die to bell the mouth? if so, measure the stem

[Bill Steele]

My 9mm sizing die, sizes my cases down to .375" OD, the average wall thickness on my mixed headstamp 9mm brass is between .012-.014", with an occasional 11 mil case.

I always felt I probably had TOO MUCH neck tension with this die (coke bottle finished round, ugh), even when loading .355" jacketed.

[beetle]

are you using an expander die to bell the mouth? if so, measure the stem

Yes I am using an expander die. not sure what you mean by "stem"? the center post inside of expander die?

thanks for your help!

[huckberry668]

Yes I am using an expander die. not sure what you mean by "stem"? the center post inside of expander die?

thanks for your help!

yes. remove it from the die and measure the stem before the taper.