Author Topic: .38 vs. 9mm (Read 2036 times)

Mike in Virginia · « **on:** October 21, 2011, 04:48:27 AM »

Why is it that a .38 Special develops less velocity and energy than does a 9mm out of the same length barrel firing the same weight bullet? I mean the .38 case is a lot more spacious than the 9mm--more space, more powder. From looking at the different manufacturer's specifics, a .38+P 125 grn. jhp gets about 900 fps, some a little less, some a little more, but the 124 grn. 9mm +P gets close to 1200 fps. Is the .38 deliberately under loaded? Is there that much gas escape from a revolver?

Bigeasy · « **Reply #1 on:** October 21, 2011, 05:39:53 AM »

Compare the pressure difference between the two.

Larry

bilmac · « **Reply #2 on:** October 21, 2011, 08:31:35 AM »

I don't know where you got 900fps for a +P 38 125gr. I"m not going out to get my books, but I'm thinking more like 1100 to 1200.

timothy · « **Reply #3 on:** October 21, 2011, 09:34:15 AM »

Considering you can make 357 magnum loads in 38 brass id say yes it is underloaded. The 38 was originally loaded with black powder so when the switch to smokless happened it left a lot of empty powder space in the case at comparable pressures. The 357magnum was basically an updated 38 special only this time it was full of smokless powder instead of black. The only reason the magnum is longer is to avoid chambering in 38 cal guns. So dont let anyone tell you the 9mm is a more powerfull round. The same thing happened to 44special and 45colt which became 44magnum and 454casull when filled with smokless.

Savage · « **Reply #4 on:** October 21, 2011, 11:21:02 AM »

As others have stated: The special is a relatively low pressure round, and a LOT of the revolvers chambered for it are not made to withstand the +p pressures. In the interest of safety, the slightly higher pressure +p should not be fired in a revolver not rated for +p pressures. The 9mm was designed as a high pressure, smokeless powder round giving it a velocity advantage over the special. If a higher level of performance is needed than the .38 spl delivers, then a .357 mag is the way to go. There is little to be gained, and a lot to lose by exceeding the design pressure limits of any cartridge/firearm.
Savage

Mike in Virginia · « **Reply #5 on:** October 21, 2011, 12:45:24 PM »

Thanks. You guys know a lot more about ballistics than I do. I got interested when someone gave me an unfired but old nickle plated Model 36. That prompted me to look for the best ammo for it, 'cause it sure is easy to carry. The latest thing seems to be Speer's "short barrel" 135+P load, but when I looked a the stated ballistics I got confused. 860fps and 222 ft. lbs. of energy. Surely that wouldn't be too much for an all steel Model 36. Comparing that Speer load to the 9mm or .44 Spl. I usually tote, it's seems a bit risky to carry the Smith.

In the old days (before autos caught on with the PDs), my Dept. issued 2" Model 64's to the plain clothes guys, and I carried one for years. And that was before the modern loadings came along. I never knew I was so under-gunned. Before +P, in the 60's, my dad worked for ATF and their issued .38 fired the old yellow box Super Vel 110 grains. I still have some of that stuff, but it's 50 years old.

I know it's an old argument, but what do some you who know ballistics carry with confidence? Are there any old timers around who carry a snub .38?

bilmac · « **Reply #6 on:** October 21, 2011, 12:53:40 PM »

OK you guys forced me to go out to the garage and get my books. According to Sierra 125gr bullets in the 38sp shows 3 loads that reach at 1200fps and two that go 1250. My book is pretty old and they loaded things hotter before the lawyers started getting rich. None of these loads are shown as +P. I think the book was printed before the days of +P.I bet a lot of +P factory reach these levels or more.

mcwoodduck · « **Reply #7 on:** October 21, 2011, 01:30:36 PM »

My guess for standard load vs standard load.
The 9mm is an auto and the 38 is a revolver. The 38 has a huge air gap that allows some of the pressure pushing the bullet to spill out. The semi auto does not.
If you were to take two J frame S&W revolvers the model 60 (38Spl) and a Modle 940 (fired 9mm from a full moon clip) 130 grain ball Specials and 124 grain ball ammo 9mm will be about the same from the two inch barrels. The foot pounds for either will be the same (so close to be insignificant)
Hand loading, getting +P or +P+ ammo for either will skew the results.
All said and done out of a standard 4" gun 9mm and 38 Special are going to be equal terminally.the guns are about the same size. (my sig P226 is about as long as my M10 and about as high) The difference is the new ammo loaded thatcan take the 38Special to the +P+ loadings (if your gun can handle them) Would i shoot them in My 90's early Model 10, yep in my late 60's Detective Special, NO.

Mike in Virginia · « **Reply #8 on:** October 21, 2011, 04:15:30 PM »

bilmac, what are some of those loads you refer to? Is it legal to quote them here? Anyway, thanks for going to the garage and looking it up. I feel better about the .38.

timothy · « **Reply #9 on:** October 21, 2011, 11:26:24 PM »

Its only recently manufactures have started this whole self defense specific short barrel 38 special thing. Years ago i used to carry white box corbon 125's rated at 1150fps. The same load now is rated at 950fps, its the same load but now they list the 2'' velocity on the box instead of the 4''. Not many people carry 4'' 38 specials anymore and j frames have become the standard platform for most 38 specials at least in the defensive ammo venue. So they now list 2'' velocities instead of 4'' because thats what most are carrying. Mike dont doubt your 38 nothings changed, except todays bullets are better than ever.

bilmac · « **Reply #10 on:** October 22, 2011, 01:56:51 AM »

Before almost everybody switched to autos, my agency, Fish and Wildlife Service issued +P+ 110gr ammo. It was special contract ammo made specially for the government and especially because of the many 2" guns being carried.It was about the only load that the gvt. could find that would reliably expand the bullet when fired in the snubbies. It probably hasn't been made in ages, but if you can find some of that stuff you will have some of the last best technology for snubbies. If you know any Fed cops who were working at the time most of the gvt switched to autos, they will probably have some. It is specifically head stamped +P+ and was made by Win and Fed at different times.

Skeeterbaymac · « **Reply #11 on:** October 22, 2011, 05:43:36 AM »

The good old days. "Young feller here's a 4 inch 38 spl and 18 rounds of ammo now go out and enforce the law"

I am retired fed LE and worked for 3 different agencies during my career. At one time or another I have seen 2, 3, and 4 inch 38'spl revolvers issued and 3 inch and 4 inch 357mag revolvers issued. Most of the ammo I was issued was usually some kind of 158 grain load for the 357mag and some kind of 125 grain or 158 grain load for the 38 spl. In later years almost all the 38 loads I was handed were the Federal +P 147 grain Hydra shocks. I did work one time with some guys from another agency that were issued a Remington 110 grain SJHP load in both 38+P and 357 mag. When I asked about why they used such a lite round I was told their agency was concerned with over penetration in crowded areas. I got to shoot some of the Remington 357 mag 110 grain loads and they were zippy to say the least. They had a big old deep and thin hollow point and I often wondered if they would hold together enough to penetrate.

bilmac · « **Reply #12 on:** October 22, 2011, 06:28:42 AM »

A problem with the light hollowpoint ammo is that sometimes it doesn't expand, then it is pretty worthless. The explanation is that the hollow cavity gets filled with clothing which makes the bullet into a solid.

There are other ways to make snubbies work. One old idea is to use big old long bullets like 180 or 190s. These are thought to tumble and work pretty good. Another is to use wad cutter bullets. I think that if I was depending on a 38 snubbie that is the way I would go. If I wasn't worried about lawyers I would use solid wadcutters loaded up to 1000fps or better. Some folks load hollow base wadcutters backwards. I don't think I would trust that idea. There was a lead 125 gr. bullet load made by Federal called the nyloc that was supposed to be good.

Brett · « **Reply #13 on:** October 22, 2011, 10:59:57 AM »

I think findings of the most recent studies have shown that the good old fashioned wad cutter is as effective if not more effective than all the fancy-smancy hollow point 'personal defense' loads. They penetrate deeper and cut an uglier wound channel than the PD loads.

reliquary · « **Reply #14 on:** October 22, 2011, 04:03:41 PM »

In the olden days (1970s) when I carried a Smith Airweight Bodyguard, I loaded the hollowbase wadcutter, inverted, over a moderate charge of Unique. It expanded very nicely in cantaloupes and a couple of armadilloes.

Unscientific testing: all I can say is that my load seemed to have about the same amount of recoil as a factory 158-grain LRN, but better terminal results.

There were stories circulating that too stiff a charge would deform the slug before it engaged the rifling, but I never experienced that.

coyotejoe · « **Reply #15 on:** October 23, 2011, 07:03:28 AM »

I once had a hollow based wadcutter separate in the bore, leaving the base stuck there. The next round fired bulged the barrel. This was in an old Enfield revolver in .38 S&W caliber with a very light load of Red Dot powder. I believe this happened because the revolver had a very large forcing cone. The bullet base expanded into the oversize forcing cone and rather than swaging back down to bore diameter it just pulled apart.
My point being that if you intend to load wadcutters at all on the warm side it might be best to choose a hard cast plain base bullet over the hollow base. I obtained some hard cast 180 grain full wadcutters for my .44 bulldog which I load to about 1,000 fps and feel that is about the best defensive load possible within the limits of the Charter Arms .44 Bulldog revolver. If I were using a .38 I think I'd run something similar, a hard cast flat base wadcutter. You can't get a larger meplate than a wadcutter and load them as hot as can safely be done.

bubbinator · « **Reply #16 on:** October 23, 2011, 10:25:20 PM »

+1 bilmac on the Gov't +P+ 110 rds. I have about 250rds of WW+P+ in white boxes with a red stripe marked LE ONLY that shoot just fine from my 3" M36 and M 642 S&Ws. I got them from fellow USAF SPs working the first Sky MArshall program decades ago. Loads listed as Defense Loads in the old Speer #8 manual turn out some spectacular 110 JHP loads using SR4756! Read the book-no loads quoted by me-but trust me-they were awesome!

Mikey · « **Reply #17 on:** October 24, 2011, 02:17:23 AM »

38 Spls run from 15k psi to 19k psi (+P). 9mm runs to 31k psi, almost twice the pressure. 38s used a standard 158 gn slug, 9mms started with 125s and dropped to 115s, so of course your 9mm is going to go faster than the 38.

A all steel m36, whether nickled or not, will easily handle standard pressure 38 158 gn loads.

Personally I would not bother with +P 38 Spl loads - I would simply load heavier bullets like the 168 or 200 gn slugs. In penetration tests the standard pressure heavy slugs penetrated further than the hollow pointed +Ps and as I have said before, when dealing with predators you want a bullet that will penetrate through tissue, bone and viscera and continue on - you most likely won't get that with some +P hollow point if your target is a super sized user of MacDonald's french fries high on meth - predators and other wild animals (including druggies) do not think about hydrostatic shock but when a heavy slug courses through thier system front to back and busts out through thier spine and brings them down they may have cause to think about something else, like mommy.....

As for those sky marshall loads, which were early Super Vels - have you ever seen anyone on a airplane wearing 4-5 layers of thickly padded insulated clothing? Probably not. They also did not want those loads to penetrate the aircraft hull and cause decompression.

NickSS · « **Reply #18 on:** November 03, 2011, 09:23:11 PM »

As several people have already stated the 38 and 9mm run at much different pressures hence the velocity difference for similar weight bullets. Personally I like a 9mm with 124 gr bullets of good make fir self defense but I also carry a 2 inch snub mose 38 on occasion just because it is easy to carry and reasonably potent. After a lot of testing on various inanimate targets and live animals of various sizes I have settled on standard full wad cutter ammo in my snub nose revolver. The 148 gr flat nose slug penetrates well at close range, does not make a huge amount of noise and effectively stops most critters I have shot with it more reliably than any of the HP ammo I have tried in it.

williamlayton · « **Reply #19 on:** November 04, 2011, 12:49:35 AM »

I always vote large and thump.
Blessings

BAGTIC · « **Reply #20 on:** November 10, 2011, 06:35:11 PM »

A .38 bullet, even a cylinder full of them, will not cause decompression of an airplane fuselage. They are not airtight like a balloon. They already leak more air that would escape through those little holes.

bilmac · « **Reply #21 on:** November 11, 2011, 01:43:42 AM »

I think that the Glasser bullet which is essentially a bunch of lead shot compressed into a copper bullet jacket was designed to be extremely effective as a man stopper, and still unlikely to penetrate an aircraft's skin. Then as Bagtic says either the airplane people clued the gun people in, or everybody got smarter together.

mcwoodduck · « **Reply #22 on:** November 11, 2011, 04:24:07 AM »

Quote from: bilmac on November 11, 2011, 01:43:42 AM

I think that the Glasser bullet which is essentially a bunch of lead shot compressed into a copper bullet jacket was designed to be extremely effective as a man stopper, and still unlikely to penetrate an aircraft's skin. Then as Bagtic says either the airplane people clued the gun people in, or everybody got smarter together.

NO. It was a speculation thaty they would not but the skin of a plane is very thin, and the interior is plastic with a foam insulation back. The super structure frame of the plane is what gives it strength. The idea of safty slug was that it would not leave a body and the parts that did would not be leathal while causing massive tissue damage in the target.
So shooting a person in a crowd would not endanger the people be hind the target.
But think about it. If foam rubber, a thin skin of plastic and a thin skin of Aluminium would stop a bullet so would a heavy leather jacket and a layer of fat.

williamlayton · « **Reply #23 on:** November 12, 2011, 12:35:06 AM »

MC
Are you calling me fat?

Must be my paranoia again.

Actually the 9m and .38 are the same size in diameter.
I don't have a 9mm shell casing for comparison.
The .357 shell casing is longer than the .38. The .38 super/9x23 are smaller which accounts for the higher pressures generated.
Blessings

bubbinator · « **Reply #24 on:** November 19, 2011, 07:05:51 PM »

To Mike in Virginia-Get a copy of the Speer #8 Reloading Manual. That's what I cut my teeth on reloading in the early 1970s. It has a "Defense Load" chapter that you won't find today in any manual I've seen since. SR4756 powder makes an awesome load in a 2" 38.