.38 special vs .38 special +P

[BernieD]

What is the technical difference? I understand that +P is a more potent round, but that's as far as my understanding goes. How does it work? I figured some people who reload a lot could explain it best. Bear in mind that if your answer is TOO technical, I probably won't understand.

 

[dstark]

+P's are loaded to a higher pressure, my ballistics book show standard .38's at 17,000 psi, and the +P's at 18,500 psi.

 

[ArchAngelCD]

As said, +P loads are higher pressures than standard .38 Special rounds. It all has to do with SAAMI specifications. SAAMI is the governing body who sets the pressure and size standards for ammo so that it will fit and be safe in all guns chambered in that caliber. Here is the link to the SAAMI site so you can read about what they do. Here is a link for the SAAMI pressure limits.

 

[243winxb]

38 special, standard, +P and +P+

As said, +P is more pressure, velocity. +P+ is for Police sales ONLY. It is higher pressure, velocity than +P An example is Federal Hydra-shok, 38 special +P+ 147gr, 900 fps 4" vented barrel. The SAAMI pressure for the 38 +P has been raised to 20,000 PSI, if my imformation is correct http://www.handloads.com/misc/saami.htm Some firearms are only rated to safely fire standard velocity ammo. Putting +P ammo in this type of gun would stress the frame and other components of the firearm. IN 9mm, there are +P and +P+ ammos also available. Some reloading sites online will give you data. The Alliant powder guide(available from them) list standard and +P loading.

 

[Galil5.56]

Speer +P data for .38 Special uses the 20,000 psi std.

 

[ants]

To the best of my simple knowledge:
The industry organization SAAMI sets standards for commercial sporting arms cartridges and their +P variants.

However, SAAMI does not set standards for military contract ammo, nor +P+.
Military ammo is determined by specifications in procurement contracts.
To the best of my knowledge, no organization is setting international standards for +P+.

 

[dstark]

The SAAMI pressure for the 38 +P has been raised to 20,000 PSI, if my imformation is correct

It could very well be correct, my 'Ammo & Ballistics' book is a few years old.

 

[ArchAngelCD]

It is correct according to Speer's own literature on that .38 Special +P ammo. They are going by the older 20,000 psi standard. For some reason SAAMI dropped the pressures of the .38 Special and .38 Special +P. (and the .357 Magnum too) According to all good guessing it's because of the super light revolvers that are now on the market.

Old SAAMI Specs:
.38 Special 18,000 psi (I think) now 17,000 psi.
.38 Special +P originally 21,500 psi then 20,000 psi. Now it's 18,500 psi
.357 Magnum was 40,000 psi now it's 35,000 psi.

 

[jfh]

I think the 38+P standards issue (i.e., which is it, 18.5K or 20K) goes something like this:

1. The last published SAAMI standard is at 18,500--about 1992, IIRC.

2. The cartridge mfrs balked; the performance for SD loads was too low for what had become common performance.

3. SAAMI raised the standard to 20K--but they have not published the update yet. So, they show the 18.5K, as in ArchAngelCD's link. This was discussed in another thread--which is where this information was from, I and consider it credible.

4. Meanwhile, there is yet another standard--CIP, or 'the European' standard. It makes no differentiation between 38 Special and 38+P; max pressure is (the equivalent of) appr. 21,750 PSI.

If you think about this--it suggests that all modern 38 Special revolvers--i.e., those manufactured since about 1984, when CIP adopted this standard--should be safe, if not long-lived when using ammo built to this standard.

I'm working on sorting out CIP loads with various powders, but I have no reliable resource yet except for Ramshot. If anyone has CIP recipes for powders available in the US, PM or e-mail me.

5. And, of course, there are the "38+P+" loads--these were developed in the 70s, when wheelguns were still the standard-issue LEO firearm, and frequently 38 Special frames. However, no standard--save for (perhaps) some manufacturer's personal criteria--evolved for 'official' SAAMI standards. Except for certain states that might have written laws to cover sales of '+P+' ammo, the "LEO-only" sales requirement is / was strictly a manufacturer's policy, and not a legal burden for the non-LEO buyer.

Jim H.

 

[Galil5.56]

All these gyrations as to what makes a +P is comical... Like you go from safe @ 18.5 k psi to "warning will Robinson" @ 20 k psi. C'mon SAAMI, all the fuss for 1500 psi CYA.

Reloading over decades gives you some perspective, and I like to look at my older Hercules manuals (circa 1980) that show a full 5.5 grains of Unique/158 LRN that is not even listed as +P! I have watched this load go down, up a little, and today Alliant lists 5.2 as a +P max. I have always used 5 grains as my personal max in a +P rated J frame, and could go higher if the pressure signs I see are any guide. I always hear powders have changed, pressure gathering techniques are more accurate...

Unique is the same as it has been for decades other than normal lot-to-lot variance and recent attention to more consistent flake size, and although pressure gathering techniques have changed, decades of millions of rounds fired w/o seeing cylinder chunks stuck in foreheads using older data seems to validate to me, and in my personal experience that the original 5.5 grain charge is reasonable. Sure, it *may* be a bit harder on the gun, but it is still safe and has always been.

 

[FM12]

+P=Hot load. +P+ = Holy Cow! How's that for simple? These are loaded hotter than normal factory spec loads, and are rough oin your gun and sometimes, your hand. Be careful, if you need a hotter load that regular loads, consider a .357 mag.

 

[Peter M. Eick]

Galil,

I am like you 5.0 grns of Unique, 158 grn lead was my standard for many decades in 38 special. I was shocked when I found out that was a +P+ round years ago when before it was not even +P in my old manual. I swung around and loaded wimp 38's for a while and yet now I am back to 5.0 grns of Unique and a 158 because it is accurate in my guns. I am not worried about wearing them out because the wear is so spread around.

It is entertaining to watch the SAAMI and others manipulate the pressure standards. I understand the why but I wonder why they did not just change the piezo standard to match the pressures generated by common loads instead of the other way around.

 

[Walkalong]

You are not going to wear out any modern quality gun with that load Peter M. Eick. The same guns with a longer chamber shoot magnums for gosh sakes.

And if your shooting it in your nice 38/44's, you are surely good to go.

That said, don't go hot rodding your .38's folks. I am just saying that going from 18.5K to 20K is not a huge deal in a modern gun.

 

[Galil5.56]

It is entertaining to watch the SAAMI and others manipulate the pressure standards. I understand the why but I wonder why they did not just change the piezo standard to match the pressures generated by common loads instead of the other way around.

Whanna see some real hocus pocus at Alliant... Check out this post:

http://www.thehighroad.org/showpost.php?p=4014514&postcount=1

Funny how my Lyman "Handbook of cast bullets" from the late 50's gets the velocity pretty darn close in 9mm with a 6 grain max charge of Unique/125 grain cast for 1300 fps (I get an actual measured 1180 fps with 5 grains/125 cast in a 5" barrel). They also get 972 fps in .38 Special with 5.2 grains as a max charge with a 158 lead bullet... Exact same +P charge weight as today's Alliant manual that states 919 fps, and without knowing the barrel length used for either, I'd say that is pretty damn good! No such thing as "+P" back then, and I don't think beautiful old S&W M&P's, and Colt Police Positives were "blowing up" or suffering any harm when used with these loadings. Everything old is new again. Oh yeah, they used this hyper modern chronograph, or flash trigger, not sure:

View attachment 90243

Along the same lines, Handloader Magazine from 1969 lists 6 grains of Unique as max in 9mm with a 125 jacket bullet for 1200 fps; a figure that is almost exactly what I get today, and a load I routinely use despite having gone up and down over the years. Obviously I am all for safe reloading, and I do think some loads for .38 Special are too much (Speer #8) but I think way too many were far too wimpy, and I'm awfully glad I have my chronograph to "de-lie" some published data. I think we give these earlier ballistic pioneers far too little credit, and think time has proven a lot of what they came up with as prudent, safe, effective, and most importantly correct.

 

[ArchAngelCD]

I have to totally agree with Galil5.56 on this. I can take it if they are telling me to lower the charges because the better testing methods are showing the loads to be too high a pressure. What I can't take is them telling me a 20% drop in powder charge will generate the same velocity than before the drop. That just can't happen unless you change the powder.

 

[10 Spot Terminator]

Point to keep in mind here is that "MANY" of the hanguns chambered for .38 special are not built to handle the +P loads and you need to know if your gun is capable of using the hotter loads. Using them in the .357 Magnum is fine but many prefer ( as do I ) to use the .357 cases and load them lighter with powders that deliver equal pressures with less dense powders that fill the cases better. I do this as I hate putting carbon ridges in my .357 cylinder from the shorter .38 cases that makes for harder cleaning .