.38 Special - Wikipedia, the free encyclopedia

Overpressure ammunition - Wikipedia, the free encyclopedia

I've heard it said on this and other gun forums by those who regularly handload and shoot a jillion +P rounds through their 1930whatever K frames that ".38+P is no big deal, it's not a hot load it's the same thing as .38 Special was years ago" before companies reduced the pressure for their cartridges while more conservative people in these gun forums say "That's not correct, .38 Special is the same now as it was 50 years ago and if the factory says it's a hot load or to not do it, then they might just know something you don't."
I've never seen this anywhere officially or in writing other than "I saw it on a gun forum" that .38+P is the same as standard was years ago. Well, now somebody on wikipedia is saying the same thing as seen in these two articles. Furthermore it is claimed that companies reduced their loads in 1972 and stamped +P on what was standard prior to 1972

I note the people on the wikipedia articles are not giving a source for their claim

Thanks Doug for bringing this up. I too have wondered the same thing for a long time. What is really the truth, and who is blowing smoke?

When I was young, the standard 38 Special load was a 158 grain bullet at about 850-900 FPS. I have chronographed numerous boxes of vintage ammo and confirmed this fact. The current standard 38 Special load with a 158 grain bullet clocks a pathetic 730 FPS. The standard load has been greatly reduced over the years.

The maximum allowable pressure for the 38 Special is 21,500 FPS. Factory +P is loaded to 18,500 PSI so it is in fact a mild load. It is not "over pressure" (as +P might suggest). It is not even loaded to full pressure. It is loaded BELOW pressure. The 730 FPS load is at 16,000 PSI, BTW.

The notion that +P is in any way a hot load is nothing but marketing hype. All that is needed is to look at the actual chamber pressure to see how mild it actually is.

I don't think anybody in here (or elsewhere) is "blowing smoke" on this question. I think both sides have valid reasons for what they say. The .38 Special has been around for like 100 years. it has a lot of history behind it.

I suspect that 38 special and 38+P are being loaded to reduced pressures. After all, the ammo countries have to load ammo to be safe in the weakest/oldest/most wornout firearm that may be chambered for it. To do otherwise is to risk multi-million dollar lawsuits when some old clapped out rusted pistol blows from a factory load, and the shooter, or a bystander, are injured. Many calibers, both rifle and pistol are being loaded by the factories to reduced pressures. This is done reduce lawsuits. Blame the lawyers, the courts and our litigious society.

typo: I meant ammo companies, not ammo countries.

Saxon,
you have the equipment to measure preassure per square inch? If not,how did you calculate the PSI for each of these rounds?

I believe what Saxon is saying is correct. I'm old enough to remember the standard 38 special round from decades past. By this I mean the 1960's and '70s. This round used the ubiquitous 158 gr. lead round nose bullet and was carried in many a LEOS Colt or Smith & Wesson .38 duty revolver (including my dad's). Now when Super Vel came along it was a whole new ball game. I still have a partial box of 38 special Super Vel from the 1970's that my dad gave me. He told me that it was department policy that only police issue standard 38 specials could be loaded in the service revolver. What you put in your off-duty revolver was your own business. I remember dad putting the SV rounds in his Smith Chief Special Airweight. As far as I know he never fired any of these SV rounds out of his off-duty gun. Probably a good thing. I keep these old "+P" rounds in my collection and would never use them since they can't be replaced. I would invite comment on Super Vel versus todays +P 38 specials (not to hijack this thread though).

Over on the Colt forum (I won't post a link as I remember the mods and admin. around here don't like people posting links to other forums) I posted this same thread in the revolver section. There is a gentleman in there who claims to have worked for two ammo companies and insists ammo loads were not reduced. That +P simply means higher pressure which doesn't necessarily mean increased velocity. I believe he is under the impression that a lot of people confuse these "old" standard .38s that give you 900 ft per second with old Hi-Speed, etc. rounds. (which, from what Saxon Pig is saying, is incorrect as he has fired many such old rounds and is positive they are standard and not Hi-Speed)

I shot a lot of the old Super-Vel ammo in both 38 spl & 357 Mag.

Now that thar is the real deal on the +P scale...Sur nuf make the ponies jump.

And let's not forget some of the 60s & 70s Norma loadings. Boy Howdy!


Su Amigo,
Dave

__________________
"IN GOD WE TRUST"

More pressure for the same velocity? Is that even possible? If so, what would be the point?

__________________
You're shy a few manners.

My old Lyman cast bullet loading manual (from the early 80's, not too old) list's the most accurate load with the lead RNFP as 4.9 gr. 231 for 906 fps. I load it and it is my most accurate load. It is not listed as a plus P, but at the top of the standard velocity loads.

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H Richard
SWCA1967 SWHF244

I fired some of the original Super-Vel loads in my standard weight Chiefs Special in the early 70s. First cylinder full, after either the second or third shot, the next round up slipped the crimp and tied up the revolver. I think the box got thrown out, but I still have 10-15 rounds of the loads somewhere.

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Georgia On My Mind

The only 38 +P round I would consider "hot today" is the Buffalo Bore 158gr +P LSWCHP round rated at 1100 fps. I don't know if this is out of a 4 inch revolver or what but I have used them in my S&W model 10 heavy barrel and believe this is not the standard +P round made by other ammo makers.
Howard

My thoughts exactly !!

Nothing to gain by adding pressure without a corresponding increase in velocity !! Just makes no sense.

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Laus Deo! <><

Doug, the individual pressure figures are published by the manufacturers. The maximum figure is from SAAMI and is readily available. No need to do your own testing.

Higher pressure equals more velocity.

In the early '70s, my Pappy bought an "S" serial numbered M&P. The salesman also sold him a box of Super Vel ammo, saying it was the best around.

Pappy shot 6 rounds, I shot 6 rounds, and my mom shot one round (# 13). The revolver jammed. An inspection showed that the forcing cone had split.

The shop sent the M&P back to Smith, who installed a new barrel. The Super Vel was swapped for a box of standard RNL ammo.

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John 3:16
WAR EAGLE!

DOUG38, interesting thread. I have often wondered about the 38 special. The one thing I have not been able to see in actual writing is the original SAMMI pressures of the pre 1972 ammo. I have heard it before but never actually seen it on a SAMMI information sheet. Do you know where I might be able to acsess this imformation?

Yup,

That SV would jump the crimp in them lighter frame revolvers.

I had a old HD and of course a 27 to shoot that hot rod ammo in.

Su Amigo,
Dave

__________________
"IN GOD WE TRUST"

I have shot 158 gr. bul. with 12 grs. of 2400 out of several post war S&W "K" frames and Colt Police Postive and Official Police without any problems but I probably never shot over a box or two out of each gun. I believe there is a good reason that S&W made the 38/44. I have shot unknown how many thousands of them out of .357 guns and I don't think a regular "K" frame will stand up to a steady diet of them. Just my opinion and it is probably worth what you paid for it. Larry

Muley Gil- There must have been a defect in the barrel. Or there was a carbon "hot spot" in the cone. It does happen. One police armorer reported Model 19s splitting cones with target 38 Special ammo. It happens. Thousands of post war M&Ps were fed Super Vel without any problems.

Wondered the same thing myself as did somebody else in that forum

There is what is called a pressure curve. As pressure goes up so does velocity. However, it is a case of diminishing returns with the gain in velocity dropping off as the pressure increases rather than maintaining a constant ratio. Going from 16,000 PSI to 20,000 results in a greater velocity increase than does going from 20,000 PSI to 24,000 PSI. At some point you reach the practical level.

I was shooting a Ruger #1 in 243 Winchester and fired a round that had a 150% powder charge. The next one in the box (unloading in reverse order) was a 50% load so I figure the powder dispenser stuck and only delivered half the powder charge, then on the next case the half charge and a full one were dumped into the case.

I happened to be shooting over a chronograph at the time and recorded over 3,400 FPS. The load should produce about 2,600 FPS so in this case a 50% increase in powder resulted in only a 35% increase in velocity. It likely caused the chamber pressure to double. Fortunately the #1 is insanely strong and other than a stuck case requiring a steel rod down the barrel to remove there was no damage.

That was me.

Pressure and velocity are related, but it is not a linear relationship. As SP noted, it is called a "pressure curve" since pressure increases exponentially compared to velocity.

At lower, ie safe, pressures, the pressure vs velocity graph can be approximated by a straight line. You do reach a point on the graph where pressure skyrockets with very minimal velocity gains. This is where things get dangerous.

__________________
You're shy a few manners.

The gentleman on the Coltforum stated he worked for two ammo companies and part of what he said was " The +P designation is for higher pressure, NOT nessessarily higher velocities."

I then asked what's the reason, or sense to jack up the pressure if it does not increase the velocity? If a company is making +P loads that only increase the pressure but don't increase the velocity and therefore, don't increase the ft.lbs. of energy delivered to the target, or assailant, why even bother with it?

I am still waiting for an answer. I am not a skilled ballistician. I have no strong opinion pro or con, I just want to hear more about this from him.
If he doesn't revisit the thread I am going to send him a polite P.M. and ask him.

A friend here at home is pretty smart and has been reloading for over 20 years. His opinion, and mine, if there is really no appreciable increase in velocity, maybe it's just a marketing ploy or marketing stragtegy?
Maybe this isn't so but in a capitalistic society, if you have 10 companies selling laundry detergent, cars, over the counter pain relievers, etc., if they all advertise they work the same, there is no reason to buy one specific product over another product or motivation for the public to buy one brand over another. That is not to say that some companies like Buffalo Bore and Corbon don't use proprietary powders or tweak the powders so that they cannot be exactly duplicated in the reloading powders. For example, the low flash cartridges that Corbon marketed flash cartridges about 15 years ago. Corbons were the darlings of self defense ammo for years. At one time, Nyclads, which I like myself.
It's all somewhat confusing to me.

BTW: I mentioned that Saxon Pig over here has done some good research on vintage standard 38 Special loads vs. today's +P loads, and I'd hoped he would chime in, but I think he spends more time here than at the Coltforum

As listed by the manufacturers +P generates 18,500 PSI of chamber pressure. This "+Pressure" is only so when compared to the current standard load at 16,000 PSI. The +P isn't really + at all, being 3,000 PSI below maximum allowable pressure for the caliber.

I believe the older "standard" loads with a 158 at 850 FPS were likely generating around 20,000 PSI. Starting in the late 1970s the fear of lawsuits caused them to reduce the loads and +P was created to fool consumers into thinking that high performance loads were still being sold by the mainstream ammo makers.

C'mon, just read the chart. Since when is a 125 grain bullet at 925 FPS any sort of hot load? I am totally perplexed at how shooters keep thinking +P is some sort of powerful load.

I'd better mention that my statements about marketing consumables for a capitalistic society is not directed to Buffalo Bore ammo specifically. I am not implying that it doesn't do what it claims to do.
I am merely pointing out that everything sold is advertised here as "new and improved".

A member of the Colt forum has chrono'ed standard Buffalo Bore 38 Special loads for a 2" barrel snubby that shows about a 15% increase in velocity and ft. lbs. delivered over average standard 38 Special loads.
To me, an increase in efficiency of 15%-20% over other loads is the threshold for making it a better load worth buying. A load that only yields say, a 10% or less gain in efficiency is hardly worth buying to my thinking.

HA! Didn't know you were over here too.

I don't recall the barrel length you use for your shooting? I do recall a historian on the History Channel* saying on Modern Marvels episode of The Magnum, that until the .357 Magnum the police all used a .38 Special firing a 158 gr Lead Round Nose bullet going at about 890 ft pre second and this was not enough to penetrate the body armor and auto bodies of the time (hence this was a call for a stronger load that eventually lead to the .357 Magnum which was intended for a stronger police gun in the 1930s)

*I know, everything on History Channel should be taken with a grain of salt.

Older ammo charts showed the standard .38 lead RN load at 860-870 FPS, probably from a six-inch pressure barrel. Modern charts use a vented four-inch pressure barrel, the better to approximate real revolvers in shorter barrel lengths. That accounts for some velocity difference.

Also, a JHP at 925 may well generate more pressure than a LEAD 158 at an "official" 860 FPS, due to the greater drag in the bore (friction) of the jacketed bullet. At best, you're comparing oranges to tangerines.

In the 1960's, I wrote to Fred Miller, then S&W sales chief, and asked him bluntly if I could fire .38-44 ammo in a Model 10. He said that it was safe, but would greatly accelerate wear to the gun, cause unpleasant recoil, and advised that I buy a .38-44 or a .357 if I planned to fire much of that ammo. I think it was sage advice.

That was the true old High Velocity .38-44 round, not modern Plus-P, note.

However, chronographed tests of some modern Plus P do show marked velocity increases over standard speed lead ammo. As a gun writer, I had access to the Federal PR man, and a few years ago, I asked if he'd be kind enough to have an engineer there fire some of their 129 grain Plus P Hydra-Shok ammo in two and three-inch revolvers and let me know the result.

He very kindly undertook that, and reported that there was about an 80-100 fps difference in favor of the longer barrel.
If anyone is interested, I can dig out his letter and confirm the actual velocities.

But even in the snub, the velocity was well over 800FPS; I think about 840 FPS. The three-inch was at 936, if memory serves. I have seen chrono results printed in the 1960's in which standard lead "service" ammo barely made much over 600 FPS, the gun being a Colt Detective Special. A Chief's Special tried about that time also gave very low velocities, 600-650 FPS. That is over a 200 FPS difference!

That does not suggest that standard loads were then any hotter than now. It could be that longer barrels generated proportionently higher velocity with the powders needing more than a two-inch barrel to get moving. But I'm pretty sure that this wasnt so, as I also saw tests in longer revolvers. The 730 FPS stated by Saxon Pig in this topic is in line with what some of those guns delivered with four-inch barrels. Sometimes,a six-incher would exceed 800FPS, occasionally making 850 FPS. Plus P loads sometimes fire lead bullets beyond 900 FPS in modern four-inch tests.
Tests in six-inch barrels of the former FBI load sometimes reach 1,000FPS.

This is a lead-to-lead comparison. I have scant doubt that modern Plus P is loaded hotter than the old standard velocity, and I think Dr. Pig is comparing JHP to lead bullets and getting a false impression.

Speer Gold Dot 125's often get very close to 900 FPS from even a two-inch barrel. Longer barrels may reach 950 or higher. These are JHP bullets and pressures are almost surely higher than for lead bullets. Bullet weight also differs. Compare that to the 650 FPS speeds of standard lead ammo in snubs in the 1960's!

I do not think that it is unsafe to fire some Plus P ammo in guns made after S&W began marking model numbers in 1957. A statement in Gaylord's, "Handgunner's Guide", published about1960, says that they were by then using a new, improved, stronger steel. But that steel was in use for years before I asked Fred Miller about that .38-44 ammo. I was then in my teens, but recall very vividly what he said about gun wear.

My own policy is that I will fire Plus P if needed, or if that's all that's available if I'm target shooting or plinking. But I won't use it in large quantities for routine practice, as it'll add to wear, and shake loose the small J-frame guns sooner. (However, recent J-frames incorporate better metallurgy, and withstand Plus P better. Model 60's with -4 or higher suffixes are made of improved steels and heat treatment, and are Rated for Plus P use. Still, I don't use it in them routinely. Certainly, when carrying for defense or animal protection, and for occasional familiarity firing.)

All Ruger .38's are more than ample for Plus P use, including the SP-101. Colt used to advise returning their alloy- framed guns to the factory for examination after firing 1,000 rounds of Plus P. Steel -framed Detective Specials and Police Positive Specials were to be examined after 3,000 rounds. Colt was concerned with the guns shooting loose (cylinder endshake) and with frame stretching.

If the gun's manufacturer makes a statement like that, it tells me that THEY think the ammo is hotter than standard speed used to be.

So, with due respect to Dr. Pig, I think there are too many variables to make a blanket statement that all modern Plus P is no hotter than the old lead service load. Buffalo Bore is certainly hotter than most, on par with those .38-44 velocities of the old days.

I wlll not use Buffalo Bore in any but .38 heavy frame guns (no longer made) and the .357's. In fact, I suspect that it is a fine combat and medium game (coyote, fox, bobcat) load in a K-frame .357 at average ranges. I mean their lead gas check Plus P lead HP.

If had to, I'd fire it in a recent Model 60 for defense or protection from animals. But I prefer milder Plus P ammo for these guns. Speer has some fine examples. And the old basic FBI load is a good one, in most cases, giving excellent penetration. Remington's version has the softest lead, and expands better in short barrels than will the Federal or Winchester versions. From four-inch or longer barrels, all three work well. This was well borne out in trials conducted by the late Steven Camp, and posted on his site. His excellent photos made a fine case for his opinions.

I wish I had a dollar for every post that I and Dr. Pig have made on this board about Plus P ammo. I could buy some of that expensive Buffalo Bore ammo...

I only know what I see on my chronograph. From a 4" revolver Remington and Winchester 125 JHP +P clocks 925 FPS (right on what they claim). From a 2" revolver it drops to around 870-890 FPS.

I shot some 110 grain "Starfire" +Ps that clocked 890 from a 4" revolver. How is this high performance?

All +P from the mainstream suppliers is loaded well below maximum allowable pressure so it doesn't matter what kind of fruit we are comparing, +P is not a high velocity load. This is the point I have been trying make. It seems blatantly obvious to me that a 125 at 925 generating 3,000 PSI less than maximum allowable chamber pressure is not any sort of high performance load.

Yet I keep encountering folks who want to argue...

Mr. Pig,
You've got to admit there's a lot going against you (gun companies, ammo companies, advertizements, certain gunsmiths, etc.) Many people consider that reputable. That said, your field tests are the reality of the situation and, over time, can say a lot more. And you've obviously done A LOT of research on this.

Ever thought of going on a show like Mythbusters or Sportsman TV with your tests? I'd like to see you sit down with Massad Ayoob or Larry Vickers and demonstrate your findings on the range. That would be on my DVR for a long time

SP,
I've been rollin my own and sendin em down range by the barrels full for a little over 45 years.

And like you, I find folk that don't know **** from apple-butter that jest want to argue for the sake of arguing.

Then there's those other folks...If they ain't pounding their empties out with a mallet
with spent primers fallin from their pockets,
they don't think their gettin top performance. Go figger...


Su Amigo,
Dave

__________________
"IN GOD WE TRUST"

I just put a 158 gr Midway LSWC through my Colt Official Police 4 inch with 6.0 grains of Power Pistol behind it (maximum Speer load). As hot a .38 Special load as I've shot so far. Put it in the cylinder with another round with 5.2 grains of Unique (maximum Speer load) and a round of 4.0 grains of Unique. Needless to say the 4.0 Unique was pretty tame, but 5.2 Unique was pretty vicious....but the Power Pistol 6.0 was slightly tougher and felt pretty impressive....that is until I dropped a Remington LHP +P into the gun and fired it....if both the Power Pistol 6.0 and the Remington had been in the gun at the same time....I'd swear they were they same. It was after sundown so I couldn't use my chronograph. I don't know which one was faster (if any) but I plan on taking the chronograph out with another load to see

Last year or so I posted ACTUAL chronograph tests of a bunch of commonly carried loads for the .38 Special. I did these chronograph tests from my personal S&W 2" M60-7 as that is what I carry most of the time, so that is what I am interested in testing. I don't really care what a specific cartridge will do out of a 6" "test barrel" (typically what Rem. Win. & Fed. will test them through), or 6" & 8 " barrels either. That said, after a few days gathering data, I found that there were only three loads that truly impressed me as viable carry loads. Those three loads are (from my 2" Chief) and I did NOT go by manufacturers published charts, I posted actual chronograph results I got over a few days of testing:

Buffalo Bore 158 grain +P SWCHP - 1040 fps.
Buffalo Bore 158 grain (standard pressure) SWCHP - 850 fps
Speer Gold Dot 135 grain JHP +P - 890 fps

The "Big Three" 158 grain +P offerings that I chronographed out of the same revolver were dismal! Most of them failed to crack the 800 fps mark, and most were in the mid 700's fps range.

BB's muzzle energy (+P 158 gr.) is about 360 ft pounds out of my 2" Chief's Special as opposed to the Big Three's dismal 230 - 250 ft pounds. BB's testing was actually slightly higher than he states on his website. He claims 1000 fps. (351 ft. lbs energy) and I actually achieved 1040 fps 360 - ft lbs energy). That is a 50% energy gain and according to what BB states and swears to, they are STILL WITHIN SAMMI Spec's! Guess what I carry??

We can debate for years to come, but I know my chronograph is accurate (tested against others) and I know that even though the BB loads are stiff, they are perfectly controllable, reliable, have not jumped the crimp, and I have 100% confidence in them.

If BB was to evaporate tomorrow, the Speer 135 gr. JHP +P would probably be my second choice. Not quite as good as the BB IMHO, but much better than the Big Three Companies stuff.

Chief38

^ See! I would think reloads could/should do better than anything mass produced out of the factory.

Old thread, I know, but it was a great read. Thanks, guys.

"The one thing I have not been able to see in actual writing is the original SAMMI pressures of the pre 1972 ammo. I have heard it before but never actually seen it on a SAMMI information sheet. Do you know where I might be able to acsess this imformation?"

It's SAAMI, not SAMMI. Not too likely, as back in those days the standard pressure measurement relied on crushing copper cylinders (CUP), a very crude method. It did not actually give a peak pressure reading, just sort of a means of comparison. Since the early 70s, most all of the factories use a piezoelectric pressure gauge having a very fast response time and giving very precise readings. CUP and piezo gauge measurements are not comparable. As a very rough estimate, a CUP value is about 20-25% LESS than the peak as measured by piezo gauge for the same cartridge in the same barrel.

It would be nice if someone would dig up some old .38 Special ammo from say the 1940s or 50s and check its peak chamber pressure using a piezo gauge against currently-manufactured ammunition. That would be much more definitive than guesswork. And in fact, all of the major manufacturers keep peak pressures produced somewhat lower than the SAAMI average maximum as a cushion of safety.

Several years ago I fired a number of Winchester (WRA) .38 Special 158 grain LRN rounds from the early-mid 1930s (dated from the box) through my 6" K-38 over my Chrony. The average MV was in the 850-860 ft/sec range. If someone has some modern factory ammunition of the same type (NOT +P), a 6" barreled revolver, and a chronograph, you might run a comparison against my findings.

Some interesting reading. Why the FBI chose .38 special.
http://historicalgmen.squarespace.co...comparison.pdf


http://historicalgmen.squarespace.co...comparison.pdf

Iggy. The link does not seem to work. I'd like to read this.
JP

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Jack
SWCA #2475, SWHF #318

Try going to this great thread about the FBI posted by lw (Larry Wack)

Click on the link about Application of Frank Baughman and the Dusty roads.

FBI's "Frank" Baughman - New Documents

Scroll down .. way down in the links on the right to Handguns prior to 1933.
there will be a link to a letter about the choosing of the .38 special.

Found it Iggy. Very interesting memorandum from Mr. Keith.
Thanks for helping me find it.
Jack

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Jack
SWCA #2475, SWHF #318

The pressures you quote are SAAMI pressure limits for .38 and .38 +P , but who's to say just what pressure the ammo makers are actually loading to today?

We might assUme they're loading near max , but unless one has actual pressure testing equipment , it's all a mute point.

And as made clear in loading manuals that list pressure , we see that higher chamber pressure does not always equal higher velocity.

For what it's worth -
My 1973 Hornady manual lists a 158 gn hollow point loaded with 5.1 gn of Bullseye @ 900 fps (we can assume the testing was done pre-1973).

My current Hornady lists the max as 4.2 gns of Bullseye for 750 fps. the +P load is 4.5 gns for 800 fps.

Quite a difference.

Besides liability I wonder how much the gun manufacturers have toned it down. When you give an unlimited warranty you sure don't want guns coming back with stretched frames or other issues from firing thousands of hot loads.

Having chron-ed a bunch of "vintage" ammo all the way back to the 30's, I can say that "in general" older ammo was close to the quoted velocities. Not always but more often than not.

So, I stand in the crowd that all 38/357 rounds have taking one full step down in power level since I started reloading in the 70's. Essentially a modern 38 special is about the power of a 38 S&W was, a 38+p today is about equal to a 38 special of days gone by. A modern 357 Magnum is about equal to a 38/44 of old. etc.

This is just based upon my shooting of vintage ammo over my Oehler 35p chrono.

Draw your own conclusions.


As to my standard 5.0 grns of Unique with a 158 lead SWC in 38 special. That used to be the standard default load for Unique for decades. Now it is past plus P in some books. I still shoot a bunch of them.

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SWCA 1646

Take it for what it's worth, but the Wikipedia page for .38 Special does make the statement that ammunition chamber pressures and velocities were reduced by the manufacturers in 1972. And I believe that it is true. This is what is said: "It is important to recognize that SAAMI changed the specifications for the 38 Special in 1972. Prior to that time the standard .38 Special was very close to today's "+P" cartridges."

I have understood that the principal reason for this was that different laboratory methods for pressure testing (the old copper crusher vs the new Piezoelectric pressure gauges) were incorporated about that time, and provided a far more precise means for measuring chamber pressure vs. time. The old copper crusher method could not come close to matching the precision of the piezo gauge, and in fact was incapable of measuring peak pressure at all. With this tool at hand, the whole concept of maximum chamber pressure was re-visited, resulting in lowering chamber pressure maximum limits across the board.

If anyone from any of the ammunition companies or SAAMI is reading this, perhaps they could supply a more complete explanation as to what happened 40 years ago.

S&W used to provide a number of the 7/8" pine boards (IIRC) their cartridges would penetrate. I don't have any of their ads in front of me, but someone here probably does. Why not just run a test of current ammo and see how many boards it penetrates? If they don't penetrate as deeply as the old S&W ads say, you have your answer.

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Guy
SWHF #474 SWCA LM#2629

There's Pine and there's pine. Different varieties, different moisture content, different age, etc. Hardly comparable to some factory information from 1960. Such a test might work in a comparative sense if someone had ammunition from, say, the 1960s and some of exactly the same type and manufacturer made recently. Measuring MVs of both rounds using a chronograph and the same gun would be far better, and that's what I suggested in a posting quite a way up the list. I'd do it, but I don't have any old .38 Special ammunition that would be suitable.