[Bogey78O]

I would've guessed rifles not pistols.

[Indrid Cold]

380 is a "9mm short"; the same bullet with less powder behind it, for semi-auto pistols. .38 is a revolver cartridge with more powder behind it than the .380. I don't think the bullet is the same, but yeah, the diameter is real similar. .38 curiously has the same diameter as the .357 (magnum).

[SevenDaysInMay]

Buy a reloading manual or better two. Hornady and Nosler have superb basics explanations with lots of graphics and specs on most current popular choices.

This is the sort of information which citizens must carry into the next Democrat fascist administration.

[Servant of the Nine]

Actually, the "38" is a .35.
Dont let it bother you, it's an old problem rising from the way cartridges were measured when they were invented.

A .38 or a .357 magnum are both .357. The .357 case is longer, and holds more powder for more power.

The .380 is a european calibre. It is actually called 9mm kurtz. it is .355 just like the longer more powerful 9mm parabellum (9mm Luger).

Dont even think about the other members of the family like the .38 Super or .357 SIG. That is when it gets very complicated.

SO9

[Ches]

Bang!

[JRandomFreeper]

I carry a .380 autoloader and my dear spouse carries a 9mm. I use the same press to reload our ammo. The same bullet is used with a different case.

The .380 and 9mmm are rimless cases for autoloaders. The .38 is a rimmed case that (typically) fires from wheel-guns.

The ballistics are completly different from one round to the other.

/john

[c-b 1]

The main difference is in the length of the case, the .380 case is approximately 5/8 inch long, the .38 case is approximate 1 1/8 inch long. The configuration of the case is also slightly different. A .380 bullet could be loaded into .38 brass, but a .38 bullet should never be loaded into .380 brass because of the slightly larger diameter of the .38.

[templar]

A .38 usually refers to the 38 special, cartridge length of 1.155 inches, overall loaded length of 1.55, usually a 158 grain .357 diameter bullet at around 750 fps.
A .380 is a smaller round, cartridge length of .680, overall loaded length of .984, bullet diameter of .355, usually a 100 grain bullet about 950 fps.

Similar bullet diameters are found in the 9mm luger, 9mm largo, .357 magnum, 38 automatic, 38 super automatic, 38 Smith & Wesson (which is the largest bullet diameter at .360), and a few rare old cowboy and BP guns.

None of these have an actual .380 bore, most are .355, .357, or .360.

[absalom01]

This should bring the handloaders out on a slow news night..

The souce of your confusion is in thinking of the numerical designation as a strict caliber, or bullet diameter (actually, the dimension between the grooves of a rifled barrel, but that's more detail that you asked after.)

These are cartridge designations -- properly, the .38 Smith & Wesson similar to the .38 special, aka the .38 Smith & Wesson Special, designed by that company, and for years a standard cartridge for police in the US. The case diameter is .379", with a bullet diameter of .357". (As a poster above noted, this is the same case diameter as the .357 Magnum, more properly known as the .357 S&W magnum.) IOW, you can use a .38 S&W Special cartridge in a .357 Magnum revolver, but not the other way around. Also, since this was designed for a revolver, it has a "rimmed" case, ie, a pronounce lip that sticks out at the bottom of the cartridge, to keep the rounds from falling out of the cylinder when you load them.

The .380, on the other hand, was designed for semi-auto handguns, and thus uses a 'rimless' case. (OK, I know that there are semi-autos out there chambered for rimmed ammunition, but that's too esoteric for this post.). Interestingly enough, this cartridge is most commonly referred to in this country as the .380 ACP (Automatic Colt Product/Pistol), but is also referred to in reloading manuals as the 9mm Corto, 9mm Kurtz, and, in English speaking countries, the 9mm Short. It has a case diameter of .374, and a .355 diameter bullet.

This is a long way round of saying that your friend at the range gave essentially correct information, but left out all of the extraneous detail that would let you understand the answer, rather than accepting it blindly.

BTW, you don't have to take my word for it. The information above comes from the Lyman Reloading handbook (happened to be closest), 47th edition.

Regards,
Absalom

[sd-joe]

The term caliber is actually used in two different ways.

In the original, it was refering to the diameter of the bullet (and the bore of the gun).

However, as companies brought out different ammunition based on approximately the same diameter bullets, it became necessary to tell them apart. Thus an approximate diameter designation was added to other descriptive words or numbers to identify a cartridge (the combination of bullet and case and powder charge and primer).

Thus the common 380 is designated the 380 ACP (ACP standing for Automatic Colt Pistol, I believe). The 380 cartridge is designed for semi-automatic pistols (not revolvers).

The most common 38 is actually the 38 Special. It is designed for revolvers.

The 380 ACP actually has a bullet diameter of .355. (That is just the way it was designed back in 1908).

The 38 Special actually has a bullet diameter of .357. (It was designed in 1902 as an improvement of the 38 Long Colt cartridge.

[Shooter 2.5]

If you're interested in cartridges and you have no intention of reloading, try to find a copy of "Cartridges of the World". It has been the Bible of gun enthusiasts since they printed the first copy around the late Sixties.

[NorseWood]

Bump for my reference file.

[boris]

Well I got a Walther PPK-S I wish I'd never bought (.380) and a Smith (pre-sellout) .38 snubbie that I love.

--Boris

[RecentConvert]

"shouldn't .38 and .380 be "close"?"

they are the same numeric value. If I remember correctly the "0" in .380 is called a significant value. This means that the third digit to the right of the decimal point in .380 is significant in the calculations and should not be omitted. So, if the number turns out to be .381 or .386 or .380, the "1," "6" or "0" should not be omitted.

I could be wrong on all this of course. I only have a GED diploma.

[Ursus arctos horribilis]

Calibers are misleading as to bore diameter. 38 calibers are a varied lot, a 38 Smith and Wesson is a .360 bullet diameter and was for weaker top break revolvers. A 38 Special is a .357 bullet diameter, the same as a 357 magnum.

The 380 ACP, (automatic cartridge pistol) is .355 bullet diameter and known in various European countries as the 9mm Short, 9mm Kurz, 9mm Breve, or 9mm Corto to differentiate it from the longer and more powerful 9mm Parabellum, also called the 9mm Luger.

As an aside, the 9mm Parbellum came out in 1902 and today is 101 years old. The venerable .45 ACP invented by John Browning was chambered for the Colt 1911 in that same year and is now 92 years old, it remains the preference of millions today and is still going strong. I think my old (Remington Rand )19111A1 made in 1943, and my constant companion for many years is the greatest combat hand gun ever made. It's form and function is timeless, once mastered, the .45 ACP 1911 is a true friend indeed

[E. Pluribus Unum]

The best way to compare two cartridges is to compare their energies at the muzzle.

The .380 has a muzzle energy of 180 foot-pounds, while the .38 Special has a muzzle energy of 251 foot-pounds.

The .38 has almost 50% more energy.

Handgun Ballistics
PROPERTIES				ENERGY	VELOCITY (feet/second)					BULLET PATH
Caliber	Item No.	Bullet Type	Weight	FT. LBS.	MUZZLE	25 Yds.	50 Yds.	75 Yds.	100 Yds.	25 Yds.	50 Yds.	75 Yds.	100 Yds.
25 Auto	25A	FMJ	50	62	750	722	695	670	645	1.83	0	-6.33	-17.50
32 Auto	32A	FMJ	71	126	900	869	838	809	781	1.19	0	-4.28	-11.89
32 Auto	32B	JHP	60	117	980	849	820	791	763	1.26	0	-4.49	-12.46
32 S&W Long	32SWLA	LRN	98	132	780	758	737	717	697	1.64	0	-5.64	-15.50
32 S&W Long	32SWLB	LWC	100	103	680	655	630	607	584	2.28	0	-7.75	-21.40
380 Auto	380SFA	SFHP	95	180	925	884	847	813	783	1.14	0	-4.12	-11.49
380 Auto	380A	FMJ	90	169	920	886	853	822	791	1.13	0	-4.12	-11.46
380 Auto	380B	JHP	90	169	920	886	853	822	791	1.13	0	-4.12	-11.46
38 Special+P	38SFA	SFHP	125	251	950	918	889	863	838	1.06	0	-3.77	-10.45
38 Special	38A	LRN	158	235	820	801	783	765	749	1.43	0	-5	-13.74
38 Special	38C	LWC	148	175	730	703	677	652	628	1.95	0	-6.69	-18.50
38 Special +P	38D	JHP	125	250	950	920	892	864	837	1.03	0	-3.77	-10.44
38 Special	38G	FMJ	132	207	840	817	795	773	752	1.38	0	-4.82	-13.27
38 Special	38N	JSP	158	225	800	780	760	741	722	1.54	0	-5.29	-14.55
38 Super Auto+P	38SA	FMJ	130	343	1090	1041	1000	965	934	0.75	0	-2.92	-8.16
38 Super Auto+P	38SB	JHP	115	320	1120	1061	1013	972	937	0.71	0	-2.83	-7.95
9mm Luger	9SFL	SFHP	95	330	1250	1239	1228	1217	1207	.46	0	-1.90	-5.26
9mm Luger	9SFB	SFHP	124	327	1090	1043	1003	969	939	0.75	0	-2.89	-8.03
9mm Luger	9A	FMJ	115	338	1150	1099	1057	1020	988	0.65	0	-2.59	-7.26
9mm Luger	9B	JHP	115	344	1160	1099	1049	1007	971	0.65	0	-2.62	-7.37
9mm Luger	9G	FMJ	124	339	1110	1059	1017	980	949	0.71	0	-2.83	-7.86
357 Magnum	357SFA	SFHP	150	480	1200	1131	1076	1031	992	0.60	0	-2.47	-6.97
357 Magnum	357A	JSP	158	505	1200	1132	1078	1033	994	0.60	0	-2.46	-6.95
357 Magnum	357B	JHP	125	584	1450	1337	1235	1155	1093	0.36	0	-1.78	-5.19
357 Magnum	357C	JHP	150	504	1230	1158	1100	1053	1012	0.56	0	-2.35	-6.65
357 Sig	357Sig-SFB	SFHP	124	502	1350	1263	1190	1132	1083	0.43	0	-1.96	-5.62
357 Sig	357Sig-A	FMJ/FP	124	512	1350	1242	1158	1093	1040	0.45	0	-2.07	-5.95
40 S&W	40SFA	SFHP	180	388	985	958	933	910	889	0.93	0	-3.45	-9.58
40 S&W	40SFB	SFHP	155	463	1160	1092	1039	994	957	0.65	0	-2.66	-7.47
40 S&W	40B	JHP	156	396	1040	1002	970	941	915	0.83	0	-3.14	-8.75
40 S&W	40D	FMJ	165	355	985	955	928	903	879	0.94	0	-3.46	-9.59
40 S&W	40E	FMJ/FP	180	388	985	957	931	908	885	0.94	0	-3.44	-9.52
10mm Auto	10SFA	SFHP	180	361	950	926	903	882	862	1.04	0	-3.7	-10.16
10mm Auto	10A	TC-FMJ	200	490	1050	1008	972	941	912	0.82	0	-3.08	-8.63
10 mm Auto	10B	JHP	170	543	1200	1117	1052	1000	958	0.62	0	-2.55	-7.21
41 Rem Mag	41C	TCSP	210	788	1300	1210	1141	1065	1038	0.49	0	-2.16	-6.15
44 S&W Special	44SA	SWC-CP	240	308	760	737	714	692	671	1.75	0	-6.01	-16.56
44 S&W Special	44SB	JHP	180	383	980	938	902	869	839	1	0	-3.67	-10.14
44 Rem. Mag	44SFA	SFHP	240	900	1300	1212	1138	1079	1030	0.49	0	-2.13	-6.08
44 Rem. Mag	44A	LSWC-GCK	240	833	1250	1168	1103	1051	1008	0.55	0	-2.32	-6.60
44 Rem. Mag	44B	JHP	180	783	1400	1270	1167	1091	1032	0.42	0	-2.01	-5.84
44 Rem. Mag	44C	JHP	240	901	1300	1217	1151	1098	1053	0.48	0	-2.12	-6.03
44 Rem. Mag	44D	TC-SP	240	900	1300	1216	1144	1086	1038	0.49	0	-2.11	-6
45 Auto	45SFA	SFHP	230	369	850	830	811	792	775	1.32	0	-4.63	-12.67
45 Auto	45A	FMJ	230	352	830	809	789	769	749	1.41	0	-4.90	-13.48
45 Auto	45B	JHP	185	333	900	867	836	805	776	1.19	0	-4.30	-11.96
45 Auto	45C	FMJ-SWC	200	321	850	818	788	761	734	1.36	0	-4.84	-13.48
45 Colt	45LB	FMJ-FP	250	355	800	783	766	750	733	1.52	0	-5.22	-14.31
*45 Colt+P+	45HA	JSP	300	1041	1250	1192	1144	1102	1066	.51	0	-2.17	-6.13
*WARNING: This ammunition is loaded to higher pressures and is, therefor, not intended for use in firearms of weaker receiver/frame strength such as the Colt Single Action Army revolver. Please consult the firearms manufacturer for compatibility and use. Abbreviations: CC - Copper Coated LRN - Lead Round Nose JSP - Jacketed Soft Point LFP - Lead Flat Point JHP - Jacketed Hollow Point LSWC - Lead Semi-Wadcutter SFHP - Starfire Hollow Point GCK - Gas Check FMJ - Full Metal Jacket LWC - Lead Wadcutter TC - Truncated Cone This Ballistics Table was calculated by using current data for each load. Velocity figures are from test barrels; user velocities may vary from those listed. The data in the table represents the approximate behavior of each loading under the following conditions: 59ºF, barometric pressure of 29.52 inches, sea level altitude.

[BenR2]

ping

[Vast Buffalo Wing Conspiracy]

The difference....besides the extra zero at the end?

If memory serves, at one time American pistol calibers were referred, for some reason, to the outside cartridge caliber, rather than the inside bore of the barrel.

Hence, the actual bore of the .38 is .357; the .357 magnum is just a lengthened .38 catridge case, with more powder and chambers capable of withstanding the higher pressures of the more modern powders used in the .357; you can fire .38 cartridge inside a .357 cylinder, but not the reverse, for safety reasons. And since these are revolver cartridges, they are rimmed.

The .380 is just the American name for the 9mm Kurtz, or short, cartidge, which is shorter (9x17mm, I think?) than the standard 9x19mm NATO (or Parabellum, or Luger, etc.). Being a semi-auto cartridge, the .380 is rimless. I think (if memory serves) the actual bore for a 9mm is .351, so it is close to, but slightly less than, the bore of the .357/.38.