9mm Bullet Diameter

bkhann · September 14, 2009, 03:56 PM

I just received my first order of Black Bullets 9mm poly/moly coated bullets. I did a test load of 50 and found that all completed loads were showing over-wide in my case guage. Upon miking the bullets I found them to be .357 (Lyman is showing .355 as the spec in the 49th edition Reloading Handbook).

I removed the barrell from my 9mm XDM and found that the bullets fit, but quite snuggly.

Do I have a problem? and is .357 within the acceptable range for a 9 mm bullet diameter?

Your thoughts?

**Mal H** · September 14, 2009, 04:25 PM

The nominal caliber for a 9mm bullet is .355". I'm not familiar with "Black Bullets", but it sounds like they sold you bullets for a .357 or .36 Special if they are jacketed. What is the bullet weight and composition? If they are a lead bullet (or copper plated), then .357 wouldn't be too bad for a size. Although most lead bullets for 9mm are .356, .357 should work with no problems.

When you say, "I removed the barrell from my 9mm XDM and found that the bullets fit, but quite snuggly", I assume you mean the cartridges fit snugly. I doubt that you could get a bullet to fit in the barrel even with a lot of pushing.

What powder and load did you load up the 50 with? (In my opinion, loading 50 rounds as a test load is about 40 too many.)

**Unclenick** · September 14, 2009, 04:34 PM

It is normal for cast bullets to be 0.001" bigger than their jacketed counterparts. If I am recalling correctly, those are plastic coated cast or swaged lead bullets. Their about 0.001" bigger than is usual for a cast bullet, but that normally would still work. Most of the Lee tumble lubes are that big.

If they're jamming up in your gun, or causing a feed problem, you could use a Lee Factory Crimp Die to size the outsides of the cartridges back down where they should be.

chris in va · September 14, 2009, 04:48 PM

Sounds to me like the moly coating is causing the extra width. I suspect the actual bullet diameter is .355 if you scraped the stuff off.

Crosshair · September 14, 2009, 06:17 PM

Well for my cast bullets I size them to .357 and they work fine. I assume you are usuing jacketed though?

oneounceload · September 14, 2009, 06:54 PM

Their site says they have a diameter of .3555. If it concerns you, you might want to call them and ask

bkhann · September 14, 2009, 07:16 PM

Thank you for your replies.

These are poly/moly coated lead bullets Round Nose 130 grains. I am using 3 familiar loads that have worked well for me with lead bullets in the past (4.1 gr WSF COAL 1.169, 6.0 gr HS-6 COAL 1.130 and 4.0 gr HP-38 COAL 1.130). All loads are conservative and I will decide which one I like the best. I expect that they will all be similar in performance, thus the 50 rounds of each.

I use a Lee Factory Crimp Die to ctimp the rounds. If I have misfeed or ejection issues, then I will not use these bullets but I expecting no problems (hoping for the best). I am trying these bullets because I like lead bullets, but I do not like the smoke that comes from the lubricant on the bullets. The poly/moly bulllets are supposed to duplicate the lead bullit, but without the smoke. They are also supposed to be very clean. we will see!

**Unclenick** · September 14, 2009, 07:28 PM

Another thread reminded me I forgot to ask what you measured them with. Calipers are off by 0.001" or sometimes even 0.002" pretty commonly. The only way to measure bullet diameters accurately is with an OD thimble micrometer with a Vernier scale for ten thousandths. You can usually find one for around $13 to $16 at Enco.

September 14, 2009, 03:56 PM	#1
bkhann Member Join Date: August 5, 2009 Location: Grand Rapids MI Posts: 98	9mm Bullet Diameter I just received my first order of Black Bullets 9mm poly/moly coated bullets. I did a test load of 50 and found that all completed loads were showing over-wide in my case guage. Upon miking the bullets I found them to be .357 (Lyman is showing .355 as the spec in the 49th edition Reloading Handbook). I removed the barrell from my 9mm XDM and found that the bullets fit, but quite snuggly. Do I have a problem? and is .357 within the acceptable range for a 9 mm bullet diameter? Your thoughts?

September 14, 2009, 04:34 PM	#3
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	It is normal for cast bullets to be 0.001" bigger than their jacketed counterparts. If I am recalling correctly, those are plastic coated cast or swaged lead bullets. Their about 0.001" bigger than is usual for a cast bullet, but that normally would still work. Most of the Lee tumble lubes are that big. If they're jamming up in your gun, or causing a feed problem, you could use a Lee Factory Crimp Die to size the outsides of the cartridges back down where they should be. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

September 14, 2009, 06:17 PM	#5
Crosshair Senior Member Join Date: December 16, 2004 Location: Grand Forks, ND Posts: 5,333	Well for my cast bullets I size them to .357 and they work fine. I assume you are usuing jacketed though? __________________ I don't carry a gun to go looking for trouble, I carry a gun in case trouble finds me.

September 14, 2009, 07:28 PM	#8
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Another thread reminded me I forgot to ask what you measured them with. Calipers are off by 0.001" or sometimes even 0.002" pretty commonly. The only way to measure bullet diameters accurately is with an OD thimble micrometer with a Vernier scale for ten thousandths. You can usually find one for around $13 to $16 at Enco. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

September 14, 2009, 04:25 PM	#2
Mal H Staff Join Date: March 20, 1999 Location: Somewhere in the woods of Northern Virginia Posts: 16,955	The nominal caliber for a 9mm bullet is .355". I'm not familiar with "Black Bullets", but it sounds like they sold you bullets for a .357 or .36 Special if they are jacketed. What is the bullet weight and composition? If they are a lead bullet (or copper plated), then .357 wouldn't be too bad for a size. Although most lead bullets for 9mm are .356, .357 should work with no problems. When you say, "I removed the barrell from my 9mm XDM and found that the bullets fit, but quite snuggly", I assume you mean the cartridges fit snugly. I doubt that you could get a bullet to fit in the barrel even with a lot of pushing. What powder and load did you load up the 50 with? (In my opinion, loading 50 rounds as a test load is about 40 too many.)

September 14, 2009, 04:48 PM	#4
chris in va Senior Member Join Date: December 26, 2004 Location: Louisville KY Posts: 13,806	Sounds to me like the moly coating is causing the extra width. I suspect the actual bullet diameter is .355 if you scraped the stuff off.

September 14, 2009, 06:54 PM	#6
oneounceload Junior member Join Date: April 18, 2008 Location: N. Central Florida Posts: 8,518	Their site says they have a diameter of .3555. If it concerns you, you might want to call them and ask

September 14, 2009, 07:16 PM	#7
bkhann Member Join Date: August 5, 2009 Location: Grand Rapids MI Posts: 98	Thank you for your replies. These are poly/moly coated lead bullets Round Nose 130 grains. I am using 3 familiar loads that have worked well for me with lead bullets in the past (4.1 gr WSF COAL 1.169, 6.0 gr HS-6 COAL 1.130 and 4.0 gr HP-38 COAL 1.130). All loads are conservative and I will decide which one I like the best. I expect that they will all be similar in performance, thus the 50 rounds of each. I use a Lee Factory Crimp Die to ctimp the rounds. If I have misfeed or ejection issues, then I will not use these bullets but I expecting no problems (hoping for the best). I am trying these bullets because I like lead bullets, but I do not like the smoke that comes from the lubricant on the bullets. The poly/moly bulllets are supposed to duplicate the lead bullit, but without the smoke. They are also supposed to be very clean. we will see!