downloading .357

Discussion in 'The Powder Keg' started by single shot, May 21, 2008.

  1. Hey - just wondering if it was cool to down load .357 mag to somewhere between .38+p and the mag velocities. I would think it would be-just looking for conformation. I am loading 110gr hornaday XTP with titegroup powder. Any problem with increasing the airspace.

    Single shot
  2. mitch_mckee

    mitch_mckee Guest

    I'd be really careful. Follow the manuals! Sure, you can do it but empty space can be a problem. The tried and true manuals will give you a good lower vel load.

  3. I'd have to agree with Mitch. I'm no expert, in the early stages of learning, but one thing I was told, you can always do what you want, but to be on the safe side, go by the manuals. If it's safe to do, it'll be in 100% of them. To go outside the box so to speak to me not only risks injury, but could also damage the firearm. Of course the more important one is yourself. As others have said, it's yours and you can do with as you wish, but do remember, you've been warned. lol
  4. samuel

    samuel G&G Newbie

    The manuals all say not to go below min.load,I believe them. sam.
  5. I'm with Samuel

    Safety is what really matters. Your safety, the safety of those around you when you shoot, and the safety of others who might (with or without your permission/knowledge) put some of your loads into their guns.

    Use the reloading manuals. They are made by professionals who understand the dynamics of what they are recommending.
    Also, the manuals cover a wide variety of performance ranges making experimentation not a viable course of action.
  6. rfc357

    rfc357 Guest

    Best to load .38 loads in .38 cases. I have seen evidence of pressure spikes with light loads in .357 cases, especially with Unique. Do not go below min loads in the manuals, especially with powders like H110 and W296.
  7. SwedeSteve

    SwedeSteve Freedom Zealot Forum Contributor

    Sticking with the manuals is really smart advice!
  8. SL11

    SL11 G&G Newbie


    Of course you can download 357 magnum cases to 38 special velocities! There is a little more space in the 357 mag case than the 38 Special case, so you would get a little lower pressures in the 357 case than you would with the same amount of the same powder in the 38 case.

    Most manuals today list "max" loads and set "starting" loads 10% below the max loads, except where there was some reason for not going even that much lower. This format doesn't tell you anything about how low you can go with most powders. But, older manuals used to show a range of velocites and the loads for different powders that would reach each of those velocities, except for velocities where a powder was not suitable. That format is much more helpful for what you want to do, because it shows loads for all velocites that the powders are useful for. Old Sierra and Hornady manuals had the many-velocity format.

    If you are stuck with the "max" and "start" load format, then you need to be careful not to download a powder that can cause problems at lower pressures. But, in working down (as oppose to working up) the most significant problem is not having enough gas to get the bullet out of the barrel and getting one stuck without realizing it. The following shot then can damage the gun and might also injure somebody.

    To do what you want to do with ony "max" and "start" data , first find powders that are listed for both the 38 and 357 with the bullets you want to use. There should be plenty of powder choices for 110 grain bullets. Note that the "max" load in the 38 is well below the "start" load in the 357. Any charge weight between those two values should be fine in the 357 case and give you power levels less than full-house 357 mag loads. If you want to go REAL light, then start using the smaller 38 case and be careful not to go below listed data for the 38, because you may stick a bullet in the barrel.

    You will also note that there are some powders that have "DO NOT REDUCE' warnings with the 357 data (e.g., W-296 and H110). Obviously, those are not good choices for less than full-power 357 mag loads, and you should not find those powders listed for 38 special.

    I have no idea why rfc357 thinks he is getting pressure spikes in 357 cases with "light" loads of Unique. Unique has a reputation for an extremely wide range of applicability, and has been loaded from mild to hot in 357 and 38 cases for decades. At pretty low power levels it is dirty, because it does not burn very well under those conditions. It may show a wide SPREAD in velocities and pressures under those conditions. BUT, it is not spiking to pressures that will damage a 357 magnum handgun.

    Last edited: May 21, 2008
  9. mitch_mckee

    mitch_mckee Guest

    Problems come when the case is not full enough and the powder charge is forward against the slug as when the gun is pointed to the ground. This leaves a gap between the primer and powder. It may happen that the primer cannot reliably fire off the powder causing a hang fire or squib load.
  10. gandog56

    gandog56 G&G Evangelist

    Yep, my first question was why not just load them in 38 special cases? You can even use the .357 dies.
  11. SL11

    SL11 G&G Newbie

    To Mitch Mckee,

    You wrote:

    If a .38 start charge is OK for a particular powder in the .38 case, then that amount of room is OK with that powder. So, the .38 max charge is not leaving more room in the .357 case than the start charge does in the .38 case, and that is OK too. Besides, he is talking about getting somewhat below start loads in the 357, not all the way down to 38 special levels. That is not a forbidden no-man's land for power.

    Many .38 loads leave a lot of room in the case, with plenty of potential for gap between the primer and the powder. Ignition is usually not a problem with fast powders, and variation is not usually that bad, either, until you get to where there is just too little powder to get the pressure up to the 10,000 psi range. It's the people trying to see how light they can load for games like Cowboy Action Shooting that are going ridiculously light and spawning all of these warnings about too-lightloads.

    (Granted, large rifle cases are a different problem with light loads, and powder position is more of a factor for them. But remember, we are talking about .38 and .357 cases here, not .300 RUMs.)

  12. mitch_mckee

    mitch_mckee Guest

    I personally had that problem with .38 spec loads. It wasn't even a light load, just a difference of profile between a LSWC and a LHP. Left enough space so that when the powder was forward, it only ignited less than half the time. I was using Unique. The result was dumping about 100 rounds and adding a bit more powder.
  13. Thanks for all the input!
    My plan is to not blow myself or someone else up! I will see if I can get some old min - max manuals. What I have is start - max. The reason for not using 38sp+p brass is I would like a little more velocity on a HP bullet and the 357 is a little bit of a handful at speed. Seemed safer to load down than exceed max load for a 38sp+p I use the titegroup powder to reload my wifes 38 snub so I have loading info for the same powder. Was mostly wondering about the case pressures. If 1/10th of an inch was enough to frett over or not.
    Just started reloading brass cases - but have reloaded shot shells before.
    More questions to follow i am sure. Going to go to the 38-55 next.

    Thanks again
    Single shot
    P.S. this is a great form - especially when ya'll get a little testy with each other
  14. SL11

    SL11 G&G Newbie


    You wrote:

    Can you post the charge weight and the bullet weight(s) that gave you the problem? Also, what primers were you using?

    Finally, what do you mean by "it only ignited less than half the time?" I am assuming that the PRIMES fired all of the times - - correct? If the primer fired but the powder did not burn at all, I would expect even a lead bullet to stick in the forcing cone and tie-up the revolver's cylinder. Is that what happened? Or, did the powder ignite and burn a little, and the bullet left the barrel, but accuracy was bad and there was a lot of unburned powder residue in the barrel and casing. The last situation is the typical result of a load of Unique that is too light for good burning in the bullet & case combination. But, it is not particularly dangerous, just "dirty." A faster powder, such as Bullseye, will burn cleaner in the same bullet & case combination, even though it uses an even smaller powder charge and leaves even more space in the case. The difference is that the faster powder reaches a higher pressure and that promotes cleaner burning.

    I have found that Unique is dirty in 38 Special loads until I load it to +P pressures or a little higher. It works fine for me in the range between 38 Special and 357 Magnum pressures.

    Singleshot says he is intending to use Titegroup with 110 gr JHP bullets. Titegroup is faster than Unique (closer to Bullseye) and should work fine in 357 Magnum cases for mid-to-low power loads. Hodgdon's 2008 manual has data for it in 38 cases at standard pressure "start" and "max" charges and +P pressure charges and also in 357 cases at "start" and "max" charges. It is the least powerful of the powders listed for the 357 magnum, because its fast burning rate limits the amount of powder that can be put into that case. It maxes out at 8.0 grains for 41,500 CUP, which still leaves the powder space in the case only about half-full.


    Because Titegroup is a relatively new powder, it is not in any of my older manuals that have the "many velocites" format. There may be newer manuals that I don't have that still use that format and show data for Titegroup. Anybody else on this forum have knowledge of such a manual?

    Last edited: May 22, 2008
  15. samuel

    samuel G&G Newbie

    SL11:good advice. sam.
  16. Single Shot,
    Do yourself a favor and get some 'Trail Boss' powder and some lead bullets. You can easily get .38 spl velocities and be shooting for a lot less money. Lots of the Cowboy Action Shooters load lighter loads in a .357 case (many reloading books show 'Cowboy Loads'). This keeps the chamber between the end of the case and the normal headspace cleaner and lets you stick to one case for all loads. You didn't mention the primer you use but I have excellant results with Winchester Primers.
    I have found that one powder for hotter loads and a different powder, and bullet, for lighter loads gives me better accuracy.
  17. redhed

    redhed G&G Newbie

    Trail Boss is a good powder for downloading a 357 mag. It has high volume and fills the case easy. Look on Hodgdon - The Gun Powder People for reloading data for this round. Here is a line of code from their web site:

    125 GR. CAST LRNFP IMR Trail Boss .358" 1.580" 3.5 874 14,900 CUP 5.3 1035 17,900 CUP

    Of course the advantage of using a downloaded 357 rather than a 38 is the fact that the round won't leave a powder ring in the cylinder.

    Here is another link to this interesting powder. New "Trail Boss" Smokeless Powder from IMR

    I like it in my rimmed cartridges where there is usually a lot of volume to fill. I usually load rounds to about 700fps with it.
    Ouch not Redhed
  18. So far I have no problem with titegroup - burns clean and ignites everytime. I use CCI pimers right now (mostly because that is what was available at the time). I have not put grits or anything else in the case yet - I eat grits and sometimes burn them but not in a cartridge. I also load them one at a time - weigh each load - check all the cases before I start seating bullets. The weapon is alot easier to clean with jacketed bullets @1200 to 1400 fps. I want enough velocity to expand the JHP bullet but make the weapon a little more controllable with the small grips on it.

    The following is from the Hodgdon website you supplied the link to:
    "As the name implies, this new spherical propellant was designed for accuracy. Because of the unique design, this powder provides flawless ignition with all types of primers including the lead-free versions. Unlike pistol powders of the past, powder position in large cases (45 Colt, 357 Magnum and others) has virtually no effect on velocity and performance. Cowboy Action, Bullseye and Combat Shooters should love this one! TITEGROUP has it all, low charge weight, clean burning, mild muzzle report and superb, uniform ballistics. Available in 1 lb., 4 lb. & 8 lb. containers."
    About $18.95 for 1# in the small town in N.E. OKlahoma I live in.
    What do you think about givin' it a try? Of course you can double load it for sure!!

    So far I love this reloading stuff,
    Single Shot
  19. Well shoot, get yourself some better grips. Even if it's a concealment gun the grips aren't the problem, it's that cylinder.
    Take a piece of soft clay in your hand squeeze it slightly then look at it. You'll see that revolver grips are shaped the exact opposite of your hand's grip shape. This has been a problem for over a hundred years. Better shaped grips will help a lot.