Light 357 magnum loads

[Jlr2267]

The low end published loading for W231 in 357 will give you a very mild load. You won't get full magnum velocities unless you get into the slower powders like 2400, W296, etc. The slower powders don't like to be downloaded. Stick to the published recipes and you'll be fine.

 

[joneb]

As for Accurate #7 with 158gr jacketed in 357 Mag. I've had good results at 10.2gr of #7 with standard primers using Rem 158gr JHP.
For a more in the middle between 38spl and 357mag with a plated bullets Accurate #5 works very well, again with standard primers.

 

[RealGun]

I found a void between 38 Special +p data and 357 starting loads. I wanted my small 357s to still be powerful but just not so punishing in smaller guns, so I load for them using data between the two calibers. If I wanted less than that, I would change guns and shoot 38 Special, always using case calibers that match what is stamped on the barrel. I picked a powder with good case fill that I could see easily enough, when placing bullets for seating. I went with 6.0 gr SR4756 and a 125 gr LRNFP. I still use magnum primers but would guess that small pistol would work fine.

 

[RealGun]

Stick to the published recipes and you'll be fine.

Except that manuals list loads for 357 that are too powerful for small guns and special target and "cowboy" applications. "357 Magnum Lite" is a less formal, less documented loading requirement. In any case, reloading is not for those who require everything to be "idiot proof". There is some education necessary to know what you are doing. For some, "just use 38 Special ammo" is the best answer.

 

[Toprudder]

As for Accurate #7 with 158gr jacketed in 357 Mag. I've had good results at 10.2gr of #7 with standard primers using Rem 158gr JHP.
For a more in the middle between 38spl and 357mag with a plated bullets Accurate #5 works very well, again with standard primers.

I tried AA#7 in 357mag with Xtreme 158gn SWC, up to 9.9gn charge, and had very bad powder-forward effect. Almost 300fps spread.

 

[ATLDave]

WARNING: THIS IS ABOUT RELOADING, AN INHERENTLY RISKY ACTIVITY; PROCEED AT YOUR OWN RISK. THE COMMENTS BELOW RELATE ONLY TO LOADING HANDGUN CARTRIDGES.

This gets at an issue that causes much confusion in reloading: what is the meaning of a "starting load"?

The answer: it varies. The method by which a great many manuals calculate a starting load is simple. First, they test to find the max load. Then they subtract 10% and call that the starting load. For starting loads calculated this way, there is nothing magic about the published starting load. It is not a minimum load, just a starting load.

However, there are some powders that do not respond well to being downloaded. Ignition becomes erratic, speeds get unpredictable, residue gets really dirty, brass doesn't seal, the load may even fail to completely burn, etc. Powders that are especially intolerant of downloading include many of the slower handgun powders.

So how do you know whether a published starting load is also a minimum load? Well, many manuals will often have a note about particular powders (such as H110) that should not be downloaded beyond a fairly high point. For the rest, consider checking a manual, such as Hornady, that lists loads other than just max and max-minus-10%.

You can also look at other applications of the powder in question. Particularly for something like .357, look at the .38 special loads. If a powder is well-suited to running at ~15,000 PSI in a .38 special load, it will probably run fine more than 10% below the 35,000 PSI .357 magnum peak! Similarly, someone loading lite for 10mm can look at .40 loads. 9mm light loaders can get some sense from .380 loads. And so on.

Remember, there is risk in going below the published loads, but the risk is very different than going above them. Barring an undetected squib/stuck bullet situation, the risk of a catastrophic problem in a low-loaded handgun cartridge is virtually zero. The action may not cycle. You may get erratic velocities and lousy accuracy. The gun may get filthy after just a couple of shots. You might get a failure to seal the chamber, which could perhaps, over extended and repeated firing, potentially cause some erosion or roughening of part of the chamber. But the gun is not going to blow up just because you dropped .5 grains less of a fast-burning powder in the case than what a manual listed as a start load, particularly if their start load is just 90% of max.

As Richard Feynman once said, "There's plenty of room at the bottom."

 

[RealGun]

I have taken note of that load for lead bullets and would routinely have used a magnum primer in a magnum case, just cuz. I wonder if that difference in detonation would have eliminated the significant ignition variances.

 

[TimSr]

I didn't notice anyone suggesting lead loads with jacketed bullets. Maybe I missed it?

I guess. not. About half the responses are people posting their LSWC and WC loads which seemed to imply it.

 

[Jlr2267]

Except that manuals list loads for 357 that are too powerful for small guns and special target and "cowboy" applications. "357 Magnum Lite" is a less formal, less documented loading requirement. In any case, reloading is not for those who require everything to be "idiot proof". There is some education necessary to know what you are doing. For some, "just use 38 Special ammo" is the best answer.

which manual has a load "too powerful" for "small guns"?

Please be specific because I'd like to research that myself.

 

[RealGun]

which manual has a load "too powerful" for "small guns"?

Please be specific because I'd like to research that myself.

My premise is that "small guns" should not be 357 in the first place. Special lower power loads make them useful and make them distinctly different than a 38 Special. It's just a personal opinion, which I often do not qualify, when quite confident of what I am writing, based upon experience. My bad.

There are so many testamonials regarding use of 38 Special in small, 357 Magnum rated guns, that it is hardly worth arguing about. Some claim no issue with the punishment from an overpowered gun, but many just download it and go about their business, valuing the concealability more than the firepower.

 

[IWAC]

My solution to the "mild Magnum" loads is to look up .38 Special +P loads in a reliable manual, (I use Speer, Lyman and Hodgdon) then working up carefully, add 5-10% to compensate for the extra case volume, IF there is no DO NOT REDUCE caution, to add a little more velocity. I use standard primers, and have a load that is reasonably mild, enjoyable to shoot, and below the starting loads for 357.

Example: 5.5 gr Unique/158gr SWC 4" 357, chronoed 860 fps. Not a mouse fart in the bunch!

If you don't care about velocity that much, .38 Special loads work just fine in .357 brass!

 

[ljnowell]

I guess. not. About half the responses are people posting their LSWC and WC loads which seemed to imply it.

People load LSWC and WC in 357 magnum too.

 

[anothernewb]

with the exception of the really warm loads on top of 110/296. all my 357s eat a steady diet of plain old lead.

Although I will say that once the supply is used up, I'll be switching to the hitek bullets.

 

[TimSr]

People load LSWC and WC in 357 magnum too.

Really? Still not sure what that has to do with the OP asking about reduced loads with jacketed bullets.

 

[ljnowell]

Really? Still not sure what that has to do with the OP asking about reduced loads with jacketed bullets.

Still not sure what your point was in the beginning. No one suggested lead data with jacketed loads. You keep adding to that.

If you saw where that was suggested, again, quote it because it's obvious I missed it.

 

[cfullgraf]

The original post...

Can a 357 magnum be down loaded . I have sierra 125 grn and 158 grn fmj bullets that I would like to make light loads . I have been using W 231 and AA #7 for my 38 special . I thought about using 38 + P powder charges . Thanks for any info .

Looks like the OP is asking about using jacketed bullets in light loads.

 

[ljnowell]

The original post...



Looks like the OP is asking about using jacketed bullets in light loads.

He is asking about using them with jacketed data, ie loading at the bottom of jacketed data. Not using lead data for jacketed bullets as implied above.