I have some unique and hp38 powder with 125jhp & 158jhp
and CCI500 primers. Will be using 357 case's in a 868, 6"bal.
would like to get between 900-1100 fps.

When I look at Hodgdon data center I don't see what primer
their using so is the CCI500 ok with what I want.

dig this: Alliant Powder - Reloader's Guide

PRINT the data and it adds the primer type.



Hodgdon Powder Company
Cartridge Load Recipe Report - 10/16/2010
data.hodgdon.com 357 Magnum
Load Type: Pistol Powder: HP-38
BW: 158

Cartridge Information
Case: Winchester Barrel Length: 10"
Twist: 1:18.75" Trim Length: 1.285"
Primer: WINCHESTER SPM
357 Magnum
Cartridge Load Data Starting Loads

--------------------------------------------------------------------------------
Maximum Loads

--------------------------------------------------------------------------------

Bullet Weight (Gr.) Powder Bullet Diam. C.O.L. Grs. Vel. (ft/s) Pressure Grs. Vel. (ft/s) Pressure

158 GR. HDY XTP HP-38 .357" 1.580" 6.2 1108 33,700 CUP 6.9 1220 40,000 CUP


NEVER EXCEED MAXIMUM LOADS

__________________
Science plus Art

The do list their data with a Magnum primer, I never use them with HP 38. I only use a Mag primer with H110/W 296.

Have not chronographed the difference so can not say if it much different.

__________________
Still Running Against the Wind

Most reloading data and especially that published by Hodgdon lists a Magnum primer with magnum ammo and a standard primer with none magnum ammo. They do this to make things easy on themselves. I disagree with the practice but it is what it is.

Unless you are using a hard to ignite ball powder like H110/W296 or HS-6 use a standard primer.

You will probably achieve higher velocities using Unique over HP-38 because it's a slower powder but since you are only looking for 900 to 1000 fps there's no reason not to use HP-38. It meters better and it's cleaner than Unique.

__________________
Freedom is never free!!
SWCA #3437

One of the most accurate loads out of my 586 is a 125 JHP, 9.0 gr. Unique, and Winchester Small Pistol (NOT magnum) primer. I have put six of these into less than an inch at 25 yards from a sitting (not benchrested) position. Virtually no recoil, either, from my 6" gun.

It's not a mild load, though. If you switch to magnum primers, you'll get signs of excess pressure so you might want to work up to 9.0 grains, starting at 8.0 or so.

Thanks to all of you for your input, I made up 50 rounds with
7.0gr of Unique and a 158gr. jhp. SPP. At 15yds. I could keep them in a 6" target. That's not bad for an old guy with bad eyes.

Tell me if I'm wrong, but when primers was hard to find the magnum primer was used in target loads or all loads. Some even used small rifle in thier 357's. The magnum primer gives a little more pep . Right or Wrong ?

I'm guessing some reloaders did but I didn't. I used the primers I thought were correct for the application.

__________________
Freedom is never free!!
SWCA #3437

At the Hodgdon data center click on the "PRINT" button and a printable version will come up. On that page on top it will show what primer to use. It took me a while to find it also.

Targetslayer

FWIW, my load is 5g W231/HP38 under damn near any bullet in a .357 case, but I typically use the Lyman 358160, 358429 or the 140g WC - can't remember the mould number.

Also, after reading a Skeeter Skelton article in the mid 80's, I took his advice and used only standard primers, magnum load, hard to light powders, everything.

I use exclusively Winchester, but I do not buy magnum in their small pistol, I use their standard. Admittedly the WLP WAS standard or magnum, but these days it is not marked so.

Using W296/H110, I have no issues whatsoever igniting my magnum loads in both .357 and .44mag.

No unburned powder, no squibs, perfectly accurate.

YMMV

Yes, no, sometimes and maybe.

Intuitively a "magnum" primer is somewhat more powerful than a "standard" one, but not necessarily. They may simply have a slightly stronger (thicker or harder) cup to resist pressure better. Velocity and standard deviation can be affected by firing pin energy, and using a harder primer can actually result in reduced velocity and wider SD spreads due to it having the same effect as reducing firing pin striking force.

The only way you will be able to know what any primer change will do to an otherwise identical load combination is to load a significant sample, at least 20 rounds, with the different primers you are curious about and then chronograph them in one session and from the same gun to see how the various loads perform relative to each other. You may be surprised to find that often velocity with the "Magnum" primer will be lower that the "Standard" one. A rifle primer may show higher or lower velocity/SD than either "pistol" primer in this test.

The one thing to remember is relative velocity relates to relative pressure approximately 2 to 1. A 5% change in velocity, + or -, indicates approximately a 10% change in pressure. Higher velocity with all other load parameters equal indicates higher pressure, always. This isn't alchemy, but rather simple fluid dynamics. Likewise lower velocity always indicates lower pressure.

Just for the record I am in no way suggesting trying this test with already maximum loadings in "Magnum" revolver cartridges loaded with H-110/296! It is an interesting exercise in moderate loadings in either standard or magnum revolvers where a fluctuation in pressure of as much as 20% (this would be an extreme situation which you are not likely to see) with mid to slow burning rate propellants, Unique or similar to 2400 or similar.

This is not conjecture on my part. It is a result of many years and many thousands of rounds of chronograph testing of several dozen different calibers in handguns and rifles. Remember that the warnings found in loading manuals cautioning against dire results if a load change so simple as a primer change can result in changing a moderate load into a dangerous one are self-serving. They are intended to frighten new reloaders out of experimentation and place them if the position in the event of a lawsuit of being able to use the defense of "We told you not to do that!". It is like the motorcycle ads that show a rider on a winding country or forest road operating the bike in a normal fashion and then displaying the "Professional rider on closed course, do not attempt". Do not attempt what, using their product in the manner it was intended to be used?

My most accurate load in my 8 3/8" 27-2 is 125gr JHP over 8.4gr Unique. The Sierra manual gives 1300 fps for this load, but that is for a shorter barrel. I have shot 2" groups at 50yds from a rest.

__________________
Corripe Cervisiam

FWIW- 6.5 gr. of W231 (same powder as HP-38) with a Fed SP Mag primer under a 158 gr. Winchester JHP produced an avg of 943 fps out of a M.19 S&W with a 2 1/2" barrel.

__________________
Andy

The minimun load for Unigue in my Speer Reloading Manual is 8.6 gr. and it shows a velocity of 1259 fps out of a six inch barrel. If you use a 38 spec. case it shows a load of 5.7 gr. generating 980 fps. It looks like you need to get some 38 spec. cases if you are wanting that kind of velocity.

Not really.... All you need to do is load .38 Special pressures/velocities in a .357 Magnum case. The reason there is such a big difference in the load data is they are assuming you want the higher velocities associated with a .357 Magnum so that's what they are providing. You can easily load 5.8gr-6.0gr Unique in that .357 Magnum case and it will be completely safe.

__________________
Freedom is never free!!
SWCA #3437

Good morning
Hard to beat 7 Grains of Unique with any bullet in a 357.
I have loaded both those bullets with as light as 5 grains with no problems for many years. My model 19-3 (3.5 ") is loaded with 8 grains and my Model 13-3 is loaded with 7 grains.