9mm brass is sizing down bullets

[KeithNyst]

I have a Walter P1 9mm that keyholed at 10 yards. Bullet is 356-120-TC that was sized to .357. I have since slugged the bore - .358, so I now know the bullets sized to .357s were too small given the slugged size. To further complicate things, the brass is sizing the bullet down to .354 (I pulled three after seating without crimping and measured the base). Load was 4.2 grains Unique, seated to 1.065 OAL.

Looking for recommendation on next things to try. I was considering beagleing the mold to try to get bullets to drop at .359 and swapping in a .38 S&W expander plug in the expander die to get bigger diameter and deeper expansion before seating larger diameter bullets. Other options?

BTW, I was pretty surprised at the reduced diameter of the bullet base from just seating. Is this common? Hardness is 11-12ish based on 2B/3B lead pencil test.

This is the first time I've tried loading cast for a 9mm. Have loaded several thousand .45 ACP without issue. Maybe I'm wasting my time trying to run cast in this large bore P1.

[Screwbolts]

It may be your seating die is set to deep and you are sizing your boolitz to .354 in your flare removal stage. Try not running your cases in your seating die so deep, run them just enough to remove the flare.

Ken

[farmerjim]

Use a Lyman M die or a NOE expander plug to enlarge the case.
A lee factory crimp die can also swage the case and boolit down.
You can increase the size of your boolits by powder coating them.

[DougGuy]

I usually seat in one stage and taper crimp in a separate stage. I set my seating die with an empty case to just remove the flare.

If you are not using a taper crimp die, the crimp band in the seating die is more or less a roll crimp which is why I use a separate taper crimp die for all the auto pistol rounds I load.

And as mentioned above, a Lee factory crimp die with the carbide ring will size boolits down in the case BUT with this die, generally if you are sizing to .356" they aren't tight enough in the carbide ring to mess with the boolit. Only when you are sizing to .358" or larger will they size down the boolit in the case. And they are not real consistent, some are tighter than others!

[Razorbak]

I size to .358 and ran into the same problem when seating, swapped out with a .38 S&W expander plug - all good now

[Pine Baron]

.38 S&W expander plug worked for me also. Inexpensive (cheap), easy fix.

[RogerDat]

Use a Lyman M die or a NOE expander plug to enlarge the case.
A lee factory crimp die can also swage the case and boolit down.
You can increase the size of your boolits by powder coating them.

This ^

The NOE expanders http://noebulletmolds.com/NV/index.php?cPath=89 fit interchangeably in the $10 Lee Universal Expander die body to make it a precise case expander/flaring die. This is same task a Lyman M die performs. https://www.midwayusa.com/product/60...0-acp-38-super Main thing is they are a precise diam. expander with a slightly larger part for flaring.

I tried the NOE expander in one caliber and found I had a very consistent tension when seating the bullet. The bullets feed in smoother and with the same amount of pressure. I have found powder coat post sizing does add a thousandth or two. I now have these NOE expanders for most calibers.

I can add one thing. Set up a drill press with a round bar in the chuck and adjust stop to squish down the bullet just a bit. The base will expand. Or drill a hole in piece of wood or metal just a small amount thinner than bullet is tall, drop bullet in hole and tap nose with hammer. The stock thickness acts as a stop. Probably would work best to start with stock as thick as bullet is tall, then sand or grind down until when struck bullet base expands to the right size and stock stops hammer. Both a little crude but was a suggestion a member made to me so bunch of 9mm I found could be used in .38 special loads. You might be able to use a small harbor freight arbor press to do a controlled "squish" to size.

Does this count as swaging?

[wbrco]

Had same problem. Was using Lee 124RN TL with bad keyholes. Slugged my barrel and my Grand Puissant is at .3572. Switched to the Lee 125 RF, sized to .358, and seat to the crimp band after comparing that depth to the 124TL. No more keyholes, no leading.

[wbrco]

Oh, and the large olgive and fp makes a 9mm cartridge look really cool.. 😁

[KeithNyst]

I made some progress by using the 38 S&W expander plug and no crimp at all. Same bullets that had been sized to 0.357 improved with the same 4.4 gr Unique load and had 1 keyhole out of 5. 4.2 grains had no keyholes and about a 2" group. I think if I drop these bullets out of the mold and don't size, I just might get some decent results ...have to wait for some decent weather to cast some. Thanks for the help.

[David2011]

I made some progress by using the 38 S&W expander plug and no crimp at all.

Danger, Will Robinson!

Glad you're making progress but not crimping in an auto loader is very risky. The boolits can be pushed deeper into the cases during feeding which will result in skyrocketing pressures and the possible spontaneous disassembly of the firearm or worse. Please taper crimp all auto loader handloads to keep the boolit where you intended. Roll crimping can have other problems since the headspace is controlled by the case mouth so it needs to be straight and not rolled into the boolit. SAAMI's drawing specs the case mouth at .380" and .700" from the case head the diameter is .3811". I would paste a link but working from my iPad isn't always as friendly as a real computer. It's easy to look up "saami 9mm specifications ".

Good on luck with this!
David

[KrakenFan69]

So if you are sizing your bullet to .356 what size NOE die would you order? .356 or go one larger?

Thanks,

Kraken Fan #69

This ^

The NOE expanders http://noebulletmolds.com/NV/index.php?cPath=89 fit interchangeably in the $10 Lee Universal Expander die body to make it a precise case expander/flaring die. This is same task a Lyman M die performs. https://www.midwayusa.com/product/60...0-acp-38-super Main thing is they are a precise diam. expander with a slightly larger part for flaring.

I tried the NOE expander in one caliber and found I had a very consistent tension when seating the bullet. The bullets feed in smoother and with the same amount of pressure. I have found powder coat post sizing does add a thousandth or two. I now have these NOE expanders for most calibers.

I can add one thing. Set up a drill press with a round bar in the chuck and adjust stop to squish down the bullet just a bit. The base will expand. Or drill a hole in piece of wood or metal just a small amount thinner than bullet is tall, drop bullet in hole and tap nose with hammer. The stock thickness acts as a stop. Probably would work best to start with stock as thick as bullet is tall, then sand or grind down until when struck bullet base expands to the right size and stock stops hammer. Both a little crude but was a suggestion a member made to me so bunch of 9mm I found could be used in .38 special loads. You might be able to use a small harbor freight arbor press to do a controlled "squish" to size.

Does this count as swaging?

[mdi]

You're not using a Lee FCD are you?

[KrakenFan69]

Um, maybe? Yes I am.

Kraken Fan #69

[mdi]

I've had experience with a Lee FCD sizing down my carefully sized cast bullets. My FCD now resides n a landfill somewhere in So. Oregon...

Seat a bullet and don't crimp. Remove bullet and measure. That will tell you if the case or FCD is sizing down your bullets.

[Moonie]

I would remove the carbide ring rather than throw it out, but I normally just purchase taper crimp dies that do not have the sizer.

[David2011]

Yes, just get a taper crimp die. You might also debur the inside and outside of the mouths of 2 or 3 cases and measure the thickness of the brass with your caliper. If your brass is thicker than normal you'll need to allow for that when adjusting the taper crimp. The SAAMI drawing shows a bullet diameter of .3555-.0030 (.3552-.3555) and a case mouth diameter of .3800 which allows for a brass thickness of 0.01225". If your brass is thicker then the mouth needs to be proportionately larger after crimping, as long as it will still chamber easily. --Or get different brass.

I reloaded for the first time in 1978 and bought my first press in 1981 but haven't loaded more than a few hundred 9mm in all that time so I'm watching this with interest. I've easily loaded 100,000 rounds in other calibers though, mostly .40 S&W and .45 ACP, all taper crimped.

Good luck!

[mdi]

Iknocked out the carbide ring on my FCD, but the crimp was uneven and far from as good as a plain old taper crimp...

Not a Lee hater, just found no use for an FCD for handguns...

[fatelvis]

So if you are sizing your bullet to .356 what size NOE die would you order? .356 or go one larger?

http://noebulletmolds.com/NV/product...oducts_id=1129

[KrakenFan69]

Thanks Fatelvis.

http://noebulletmolds.com/NV/product...oducts_id=1129