380 Auto - .356 diameter?


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RDA 226sig
May 15, 2008, 08:04 PM
I ordered some Winchester 85 grain FMJ's that were identified as 380 caliber but they measure .356+ diameter at the base. All the 380 auto reloading data I have indicates only .355 diameter. I have manuals published by Hornaday and Speer both show only .355 for the little 380 Auto. Has anyone ever loaded or seen data for the 380 auto loaded with .356 diameter bullets?

I am thinking I may try to send them back because the wife isn't buying the I need a gun that shoots 38 super use up of these bullets routine.

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RecoilRob
May 15, 2008, 08:20 PM
I personally wouldn't sweat a thousandth. Try loading a few and see if they chamber easily. If they do (and they probably will) shoot them with happiness!

Sorry, this won't be your excuse for the Super....


Oh, and Welcome to THR!

Jimmie
May 15, 2008, 08:23 PM
I just googled and found this... 380 bullets measuring .356.

http://www.midsouthshooterssupply.com/item.asp?sku=00051J130

http://lonetreebullet.com/380Cal.html

Looks like .356 isn't that unusual.

TechAlG
May 15, 2008, 08:42 PM
This is actually very common...for CAST bullets. 9mm/.380 (9mm Kurtz) will fire a jacketed bullet of .355 diameter and a cast bullet of .356 diameter; similar to a .38 special/.357 shooting jacketed of .357 and cast of .358.

Have you been able to find any reliable data for these bullets? I have a few hundred cast 95 gr Round Nose (@.356 diameter), but I can't locate the data I used for it before (lost it when I moved).

RDA 226sig
May 15, 2008, 08:47 PM
Thanks. I will try a test run loaded with a minimum powder charge and let 'em fly.

RDA 226sig
May 15, 2008, 08:51 PM
Unfortunately I am still trying to find data TechAIG. These tiny cases scare the heck out of me and I prefer to follow the book with them.

TechAlG
May 15, 2008, 09:35 PM
All the books I have only list data for jacketed; but my bullets are cast. I know what you mean about being scared of these little cases.

socaldan
May 16, 2008, 02:18 AM
Try loading .32s&w short revolver cartridges sometime.
WHAT A PAIN!!
Don't worry...you'll do fine!

The Tourist
May 16, 2008, 02:21 AM
You also have to factor in manufacturing tolerances. I know of a Python that slugged out .354 of an inch.

rcmodel
May 16, 2008, 12:36 PM
Most .380 barrels will slug closer to .356" then .355".
Some may even go .357"!

The only thing you have to be concerned about with .356" bullets is whether or not they will chamber in your gun. If the case swells enough from the larger bullet it may not chamber.

But I would be very surprised if you have any brand of .380 pistol with that tight a chamber!

rcmodel

Lovesbeer99
May 16, 2008, 02:34 PM
Send them back. All the manuals state to use .355. I know that when people load 9mm in cast the bullets usually jump to .356, just like a .357 jumps to .358, but... even my lyman cast book states that in .380, you must size the bullets to .355.

I would definately sweat 1000th of an inch unless you slug your barrel and know for sure. Send them back for your own safety.

ants
May 16, 2008, 03:00 PM
Go take apart some factory fmj 380Auto from Win, Rem, and S&B and measure the bullet. They generally measure between .355 and 356. If factory ammo won't hurt your pistol, neither will these Win bulk bullets.

As advised above, the big issue is the bulge in the brass after the bullet is seated. The 380Auto case has a tapered wall thickness. The case wall is thinnest at the mouth and gets thicker as it goes down. So a bullet seated deep will bulge the brass more as it hits the thicker wall. With these bullets at .356, load them a little longer and they will bulge the brass less (load longer as long as they still fit in the magazine). Check them in your chamber. If they fit the magazine and chamber fully, go have fun shooting!

CZ57
May 17, 2008, 04:14 PM
No problem and if memory serves, Remington's Golden Saber for .380 are also sized .356".;)

RDA 226sig
May 17, 2008, 08:41 PM
Land to land the barrel of my Bersa Thunder 380 is 0.356+ and is pretty close to 0.357. Also, I have found a pamphlet that came with my Lee reloading dies containing data for 380 ACP specifying the bullet diameter as .356.

I will start low and work my way up carefully but I feel confident with the data I have found and measurements I have made. I will post results.

rcmodel
May 18, 2008, 01:02 PM
I have got .355", .356", and .357" 9mm bullets in the same box from Berry!

Not a problem if they will chamber.

.001" increase in bullet diameter in the larger calibers is not going to change pressure enough to even notice.

Besides, it sounds like .356" is what you need to fit your Bersa barrel.

rcmodel

RDA 226sig
May 23, 2008, 07:21 PM
Finally got to the range and tried the .356 rounds that I loaded last week and they worked fine. Have a bit more snap than the factory loads but the cases and primers looked fine.

Sniper308
July 18, 2008, 04:35 PM
"I know of a Python that slugged out .354 of an inch."

Yup, mine does too. Verified time and again... .354".

I've been thinking about the Barnes 125-grain .357 SIG XPB.

Russ

Mike Kerr
July 19, 2008, 09:58 PM
I think rcmodel is correct. The variance between individual bullets frequently/usually/sometimes varies even from bullets in the same box.

regards,

:):):)

Mike Kerr
July 19, 2008, 10:16 PM
RDA 226sig
these tiny cases scare the heck out of me

socaldan
Try loading .32s&w short revolver cartridges sometime.
WHAT A PAIN!!


These statements are not exclusive of each other are they?

I have experimented with reloading 32ACP with mixed results. Despite what some Product Mfgr's claim, some powder measures/with some powders can give you fits on little bitty cases. Very tedious. Makes me wonder how those who reload .25 acp don't have neck, back and eye aches from squinting at those little bitty cases and dropping those little bitty bullets.

regards,

:):):)

CHEVELLE427
July 20, 2008, 01:11 PM
If You Look At Any Hornady Bullet,
All The Ones I Have Are 1 Thousand Larger Then The Book Calls For.

rcmodel
July 20, 2008, 01:23 PM
I think you might have a faulty measuring device.

I have never measured a Hornady bullet in any caliber that wasn't exactly the diameter it said it was in the Hornady manual and on the box it came in.

rcmodel

CHEVELLE427
July 20, 2008, 01:31 PM
I think you might have a faulty measuring device.

I have never measured a Hornady bullet in any caliber that wasn't exactly the diameter it said it was in the Hornady manual and on the box it came in.



WASN'T saying they were different in the box, there different from what a reloading book calls for i.e.: 44mag is .429 , hornady bullet is .430

rcmodel
July 20, 2008, 01:38 PM
Yes, but the Hornady book calls for .430" bullets.

That's why we should not use generic loading data for some other brand bullets.

And it's got even more critical recently with things like solid copper bullets, VLD bullets, and other exotics that don't behave the same as conventional bullets.

rcmodel

CHEVELLE427
July 20, 2008, 01:47 PM
true.
i have 4 reloading books and a hand full of paper back books
i dont have a hornady book

i dont feel 1-2 thousand is too much to worry about , like loading for an 30cal sk or ak barrels, some i think are from .308-.312

it has also got critical do to buying what is on sale

presspuller
July 20, 2008, 05:01 PM
I don't have it in front of me but I am almost positive the Lee book shows the bullet diameter as being .356 for all their data.

EMC45
July 20, 2008, 09:10 PM
My Keltec slugs at .357 so I shoot a 9MM 120 gr Lee bullet sized to .358 through it. It works great!

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