Reload data for 357 mag+P

[Mikeinkaty]

What manuals include data for the heavy frame 357 mag? Mine is the 686 L frame.

Also, how fast can you push a Hi Tek coated or powder coated cast lead bullet before you start seeing leading? Hodgdon must be assuming lub'd bullets.

Thanks,
Mike

 

[ArchAngelCD]

There is no such thing as a .357 Magnum +P. Pressure limits for the .357 Magnum are what they are and even though the S&W M686 is an L frame revolver you should not exceed SAAMI pressure limits. Usually magnum loads are the higher pressure rounds if lighter cartridges, they should not be pushed any higher.

 

[Fishinfool]

I don't know of any manuals that list "heavy" frame loads for the .357 mag. There is no recognized standard for Plus-P loadings in this cartridge.

Like any cartridge, it can be loaded powder puff up to SAAMI maximum. Any gun in good condition will safely shoot any factory .357 mag load, or its reloaded equevallent.

Where you see "heavy frame" loads is in cartridges like the .45c, that started out as a low pressure round, but can be improved upon quite a bit in modern, strong guns like the Ruger Blackhawk, or TC single shot. Most manuals show different levels of power for their loads, depending on what gun you are using.

Not so with modern mags like the .357.

Larry

 

[BB57]

If you want a .357 Magnum "+P", you'll need to find yourself a pistol or revolver chambered in .357 Maximum. It's essentially a .357 Magnum extended by .300" and operating at 40,000 psi, compared to 35,000 for the .357 Magnum.

For awhile you could get a single action Ruger Blackhawk in .357 Max as well as a double action revolver from Dan Wesson, and you can still get a single shots from T/C.

The problem with the .357 Max in a revolver is that it demonstrates serious flame cutting of the top strap - not the normal slight and self limiting cutting you see on a lot of .357 Magnum revolvers, but rather serious cutting that poses a failure risk. The result of that is no one makes a .357 Max revolver any more.

It's just another example that there is no free lunch. The .357 Magnum is probably going to continue to be king of the (practical) .38 caliber hill for the foreseeable future.

 

[BB57]

Where you see "heavy frame" loads is in cartridges like the .45c, that started out as a low pressure round, but can be improved upon quite a bit in modern, strong guns like the Ruger Blackhawk, or TC single shot. Most manuals show different levels of power for their loads, depending on what gun you are using.

Not so with modern mags like the .357.

Larry is spot on with this.

The .45 Colt is probably the best known example of this phenomenon. The SAAMI spec for .45 Colt is 14,000 psi, sometimes referred to as "Tier 1 data. Buffalo bore advertises ".45 Colt +P" ammunition for sale, but it's important to understand that there is no SAAMI standard for ".45 Colt +P".

Several powder and bullet companies list "Ruger Only" or "Ruger and T/C Only" loads but not very many actually specify the pressure being generated in these loads. Speer indicates the pressures of some of it's loads are as high as 25,000 CUP and this is probably as close to a "standard" as you'll find for the "Ruger Only" loads. Speer also suggest shooting these loads in new or once fired brass only. This data is sometimes referred to as "Tier 2" data.

The use of PSI for the SAAMI spec and CUP for Speer's quoted maximum, makes it hard to compare the numbers. There is fairly reasonable correlation between psi and CUP in rifle loads using the formula PSI = (1.516 x CUP) - 17,902; but only if you consider "reasonable" to mean within =/- 3000 psi and only for about 2/3rds of the rifle rounds out there.

It's very important to note that there is no correlation at all for handgun and shotgun rounds, so don't even think about comparing CUP and PSI for a handgun round.

You'll also find some "Tier 3"load data indicating pressures as high as 32,000 psi for the .45 Colt and this generally delivers the same performance as a 36,000 psi load in a .44 Magnum (the SAAMI max), but does so with less pressure.

Unfortunately, the logic that gets applied here is that if I have a large frame S&W in .45 Colt, it must be safe to shoot at close to the same pressure and performance levels as a .44 Magnum, since the same frame is used for the .44 Magnum.

There are two flaws in that logic:

First, just because the external dimensions of an N frame revolver are the same doesn't mean they are equally strong. S&W uses a different heat treatment on their .44 Mag revolvers to address the higher pressures and a .45 Colt revolver won't get the same treatment.

Also, the .45 Colt chamber dimensions are larger. The .45 Colt chamber dimension is .4870 at the base and .4862 at the mouth, while the .44 Mag chamber dimensions are .4600 and .4580 respectively. Both the increased diameter and the reduced wall thickness decrease the strength of the .45 Colt chamber in any given firearm, even before you take the metallurgy into account.

Second, the .44 Magnum cartridge has a .457" base dimension and tapers to .4561" at the mouth, creating a fairly small clearance at the base of only .003".

In comparison, the .45 Colt cartridge is a cylindrical cartridge with a constant diameter of .480", creating .007" of clearance at the base - over twice the gap to fill compared to the .44 Magnum, so .45 Colt brass gets stressed a lot harder to contain the same pressure.

---

From a practical perspective those "Tier 3" loads in excess of Speer's stated limit if used at all are probably best left to very strong actions, such as the Model 92 rifle or carbine (a pint sized 1886) or other arms that are also chambered for .454 Casull, and even then you want to exercise caution given the limitations of the .45 Colt chamber and brass as the .454 Casull chamber isn't just longer, it's tighter.

The .454 Casull chamber has a base dimension of .4775" while the cartridge has the same .480 cylindrical diameter of the .45 Colt, creating a clearance at the base of only .0275", tighter than the .44 Mag chamber, making it much more suitable for higher pressure loads than the .45 Colt.

 

[Mikeinkaty]

Why does Hodgdon show reload data for 38 Spl + P ?

 

[BB57]

Because there is a .38 +P standard.

The SAAMI maximum average pressure is 17,000 psi for standard pressure .38 Special and 20,000 psi for .38 +P.

9mm Para and .45 ACP also have plus +P standards:
35,000 psi and 38,500 psi for the 9mm Para and 9mm Para +P; and
21,000 psi and 23,000 psi for the .45 ACP and .45 ACP +P).

.38 Super is the oddity in that it only has a +P standard: 36,500 psi. It was already a higher pressure version the .38 ACP round, which has a maximum average pressure standard of 26,500 psi, and since they share the same case, most ammo makers started using the +P designation for all .38 Super ammo, after SAAMI adopted the .38 Super +P standard in 1974.

 

[BB57]

You may also see references to ".38 +P+" loads and you'll come across that head stamp now and then.

There is once again no "+P+" standard. Anytime you see that, it is a reference to ammunition that is loaded in excess of the SAAMI "+P" standard.

The .38/44 cartridge was a round developed for use in large frame revolvers as a "heavy duty" police round, using the .38 Special case, in part as a response to a prohibition era need for better penetration of car bodies and body armor coming into use.

.38/44 was the motivation of the development of the .357 Remington Magnum. However the .357 Magnums were expensive to buy in the 1930's, 40s and 50's so the .38/44 remained popular and remained in production well into the 1960s.

Many police departments also used .357 Magnum revolvers special ordered to be chambered to take only the shorter .38 Special, but then used with either .38/44 or more commonly a ".38 +P+" load to avoid the negative press of shooting suspect with a .357 Magnum. They could claim that their officers shot ".38 Special" revolvers and not be untruthful, yet also would not disclose that the bullet coming out of that .38 Special case was being launched at .357 Magnum velocity.

These "+p+ loads were generally not available to the general public, mostly due to the concern they'd be shot in .38 Special revolvers that were not strong enough for them.

Similarly, it was the tendency for people to shoot the .38/44, intended for large frame revolvers only, in smaller frame .38 Special revolvers that largely led to its discontinuance. SAAMI never adopted a standard for it, but instead developed the ".38 +P" standard, so that's basically where the +P standard started.

 

[ArchAngelCD]

Why does Hodgdon show reload data for 38 Spl + P ?

Like I tried to explain in my first post, magnum rounds are the top end if a lesser cartridge. The .38 Special pressures were lowered in the early 70s and a "plus pressure" standard was adopted. When the .357 Magnum was developed it was intended to be the .38 on steroids and it is.

As for the 9mm, I see no reason for a +P other than marketing and to make more money. Shooters are always wanting to turn things into something they are not.

The same pretty much holds true with the 45 Auto. That round and the 1911 has been stopping the bad guys for over 100 years but the American shooter is obsessed with velocity and labels so the ammo companies lightened the bullet, increased the pressure and the 20 round $1+ a round box of SD ammo was created.

IMO accuracy and reliability is everything and you only need enough velocity to reliably expand the bullet.

 

[fredj338]

As noted, not such data for 357mag +p. IMO, the L-frame is NOT a heavy frame 357mag. That would go to a Redhawk or sim size gun. Going off book is always up to the reloader, I wont tell you not to, but it is at your own risk. As far as how fast can you push a HT coated bullet? With my own cast & HT coated, seems about 1500fps is where accuracy starts to fall off, that will depend a bit on the alloy though.

 

[BB57]

Like I tried to explain in my first post, magnum rounds are the top end if a lesser cartridge. The .38 Special pressures were lowered in the early 70s and a "plus pressure" standard was adopted. When the .357 Magnum was developed it was intended to be the .38 on steroids and it is.

As for the 9mm, I see no reason for a +P other than marketing and to make more money. Shooters are always wanting to turn things into something they are not.

The same pretty much holds true with the 45 Auto. That round and the 1911 has been stopping the bad guys for over 100 years but the American shooter is obsessed with velocity and labels so the ammo companies lightened the bullet, increased the pressure and the 20 round $1+ a round box of SD ammo was created.

IMO accuracy and reliability is everything and you only need enough velocity to reliably expand the bullet.

The only pressures that were affected in 1974 when the .38 +P standard was adopted, were some LEO loads that were previously referred to as "+P" loads that operated at pressures over the +P standard that was adopted. Those ended up being called "+P+" loads.

When you look at the effectiveness of +P loads in law enforcement use in data on actual shoots, the .38 Special +P seems to be about 20% more effective than the standard pressure .38. For 9mm, the increase drops to 9% with +P loads and in .45 ACP it's only a 6% increase with +P loads.

 

[rwsmith]

The nice thing.....

With your 686 you can load up to the highest level in any standard reloading manual. I've shot the hottest loads out of my 686 and I don't want to do that a whole lot. With an 'N' frame they might be more comfortable to shoot.

There really is no defined term for 9mm +P or .357+P. They have simply started called them +P to say they are a little more powerful than standard loads, but as said before 9mm was designed from it's inception to be used with smokeless powder.

.38 special started life as a Black Powder cartridge and when the smokeless propellants that became available were capable of much higher performance, along with improvements in metallurgy and design. Break open revolvers were common that even when well made, tended to wear and couldn't take extra pressure. When strong, modern guns became more standard they added the +P loadings to take full advantage of the potential of the round in the mid 1970s.

.357, though based on the .38 was developed in the mid 1930s with modern powders in mind so unless you buy a non-standard gun, above standard loads are not recommended.

 

[WR Moore]

There really is no defined term for 9mm +P or .357+P. They have simply started called them +P to say they are a little more powerful than standard loads, but as said before 9mm was designed from it's inception to be used with smokeless powder.

No so, for the 9mm. Per SAAMI documentation, 9mm MAP is 35,000 psi (piezo). 9mm +P has a stated MAP of 38,500 psi (piezo).

 

[nicky4968]

There is no way to load to .35 Remington, .358 Winchester, or .35 Whelen velocities in a pistol. There is no way to get to .30-30 or .30-40 power in a pistol either.
We have all "twisted the tiger's tail" a bit when we first started reloading. Then we grew up.
Believe me, if the .38 Special or .357 Magnum won't get the job done, use the Krag.

 

[ParadiseRoad]

 

[tops]

Unless a person a person was real tall that gun would get a lot of muzzle wear if carried in a belt holster. Larrt

 

[rwsmith]

Thank you......

No so, for the 9mm. Per SAAMI documentation, 9mm MAP is 35,000 psi (piezo). 9mm +P has a stated MAP of 38,500 psi (piezo).

This is new to me. I must be behind.

 

[Mad_Charlie]

Larry is spot on with this.

The .45 Colt is probably the best known example of this phenomenon. The SAAMI spec for .45 Colt is 14,000 psi, sometimes referred to as "Tier 1 data. Buffalo bore advertises ".45 Colt +P" ammunition for sale, but it's important to understand that there is no SAAMI standard for ".45 Colt +P".

Several powder and bullet companies list "Ruger Only" or "Ruger and T/C Only" loads but not very many actually specify the pressure being generated in these loads. Speer indicates the pressures of some of it's loads are as high as 25,000 CUP and this is probably as close to a "standard" as you'll find for the "Ruger Only" loads. Speer also suggest shooting these loads in new or once fired brass only. This data is sometimes referred to as "Tier 2" data.

The use of PSI for the SAAMI spec and CUP for Speer's quoted maximum, makes it hard to compare the numbers. There is fairly reasonable correlation between psi and CUP in rifle loads using the formula PSI = (1.516 x CUP) - 17,902; but only if you consider "reasonable" to mean within =/- 3000 psi and only for about 2/3rds of the rifle rounds out there.

It's very important to note that there is no correlation at all for handgun and shotgun rounds, so don't even think about comparing CUP and PSI for a handgun round.

You'll also find some "Tier 3"load data indicating pressures as high as 32,000 psi for the .45 Colt and this generally delivers the same performance as a 36,000 psi load in a .44 Magnum (the SAAMI max), but does so with less pressure.

Unfortunately, the logic that gets applied here is that if I have a large frame S&W in .45 Colt, it must be safe to shoot at close to the same pressure and performance levels as a .44 Magnum, since the same frame is used for the .44 Magnum.

There are two flaws in that logic:

First, just because the external dimensions of an N frame revolver are the same doesn't mean they are equally strong. S&W uses a different heat treatment on their .44 Mag revolvers to address the higher pressures and a .45 Colt revolver won't get the same treatment.

Also, the .45 Colt chamber dimensions are larger. The .45 Colt chamber dimension is .4870 at the base and .4862 at the mouth, while the .44 Mag chamber dimensions are .4600 and .4580 respectively. Both the increased diameter and the reduced wall thickness decrease the strength of the .45 Colt chamber in any given firearm, even before you take the metallurgy into account.

Second, the .44 Magnum cartridge has a .457" base dimension and tapers to .4561" at the mouth, creating a fairly small clearance at the base of only .003".

In comparison, the .45 Colt cartridge is a cylindrical cartridge with a constant diameter of .480", creating .007" of clearance at the base - over twice the gap to fill compared to the .44 Magnum, so .45 Colt brass gets stressed a lot harder to contain the same pressure.

---

From a practical perspective those "Tier 3" loads in excess of Speer's stated limit if used at all are probably best left to very strong actions, such as the Model 92 rifle or carbine (a pint sized 1886) or other arms that are also chambered for .454 Casull, and even then you want to exercise caution given the limitations of the .45 Colt chamber and brass as the .454 Casull chamber isn't just longer, it's tighter.

The .454 Casull chamber has a base dimension of .4775" while the cartridge has the same .480 cylindrical diameter of the .45 Colt, creating a clearance at the base of only .0275", tighter than the .44 Mag chamber, making it much more suitable for higher pressure loads than the .45 Colt.

Very well written and CORRECT information, Thank you.

 

[silentflyer]

I you need more velocity or muzzle energy go with a .357 maximum or a .41 magnum, a nice Model 57 or 58 is a nice addition to any gun safe.

 

[fredj338]

The only pressures that were affected in 1974 when the .38 +P standard was adopted, were some LEO loads that were previously referred to as "+P" loads that operated at pressures over the +P standard that was adopted. Those ended up being called "+P+" loads.

When you look at the effectiveness of +P loads in law enforcement use in data on actual shoots, the .38 Special +P seems to be about 20% more effective than the standard pressure .38. For 9mm, the increase drops to 9% with +P loads and in .45 ACP it's only a 6% increase with +P loads.

Was that really the +p loading or the bullet type used? Back in the day, the common 38sp round was the 158gr LRN. Then they went to a LSWC, then the +P loadings were 158grLSWCHP. Just curious what those numbers would show.