Light loads for .357 Magnum

mgulino

New member
Has anyone tried loading .357 magnum cases down to 38 Special levels? I want to load light .357 loads, but do not want to use 38 Special cases to prevent the carbon ring build up inside the chamber. I use the Hodgdon Reloading site for most of my reload data. Using TiteGroup (I have used other powders, and am open to suggestions), the .357 load data shows 6.8 – 7.5 grains for the 125 grain Hornady XTP and 6.3 – 7.0 grains for the 140 grain XTP. For the 38 Special, Hodgdon shows 4.3 - 4.6 grains for the 125 grain XTP and 3.9 – 4.2 for the 140 grain XTP. The 38+P data shows a max load of 5.0 grains for the 125 grain XTP and 4.6 grains for the 140 grain XTP. There is no overlap between loads. Is it safe to load the 38+P or 38 special load in the .357 case?
 
I want to load light .357 loads, but do not want to use 38 Special cases to prevent the carbon ring build up inside the chamber.

Have you had that dreaded carbon ring built up (to the point you can't fully insert a .357 case?) before???

IF so, how many rounds of .38 (without proper cleaning) did it take??


I've never had that problem happen to me, in any of my .357s, though I will admit that A) I don't shoot crap ammo, and B) I don't think I've run more than 300 rounds or so of .38 at any one time.

I understand it can happen, but I think its frequency is overstated.

People have been loading .357 cases with less than full .357 level loads since it first came out in 1935. Not all that often, because there's no real point to doing it, and there is a cost.

Every loading/firing cycle uses up some of the brass life. If you want to use up .357 brass life with .38 Spl level loads, its your choice. You're paying for the brass. So, if that cost doesn't matter, then its all good.

And, get a BOOK, better yet get several. Not just for the data. Books also work when your internet is down! :D
 
I haven't used any 38spl cases in thirty years or longer. I shot competition with my 357mag revolves and just loaded 38spl loads in them. As far as case life goes.....I have cases I bought at least twenty-five years ago and I'm still using them. Case life on 357mag brass loading to 38spl levels is unbelievably long. Once in a great while one splits and that's mostly from over expanding the necks. There is no penalty using 357 cases to load 38spl loads if you're shooting in a 357 revolver. As far as the carbon ring in the gun...that takes about five minutes to clean out. It's no big deal at all. Even using 357mag cases you're still getting a carbon ring from firing after a while. Don't over think it.
 
Any .38 Special +P load will work just fine in .357 brass. Any max .38 Special load will also work just fine. For any powder with .38 Special and .357 Magnum data you can use loads in between the listed loads in .357 brass

If you try to use light .38 loads in .357 brass they will be dirtier than normal and might start getting erratic velocities on the low side. Go too low and you'll eventually stick a bullet in the barrel.
 
Aim for about 1050 to 1100fps with 158grain lead. The loads will be mild, shoot flatter than a 38 and be more consistent that a 770fps load in a magnum case.
 
We're also curious what gun(s) you'll be shooting these through; specifically, the barrel length?. And. . . do you have a chronograph?

This subject comes up a lot. And I understand the logic. But I'm rather opposed to the notion, but have also softened my stance on it. I know there are plenty loaders out there successfully (as defined by them) doing it. And I too have "detuned" 357 ammo; but it isn't downloaded all the way down to 38 Special pressures. I too prefer to avoid shooting Specials in my magnum revolvers (but do some). That ring buildup is a bit annoying; and I find it more of a nuisance than 44 AMP characterizes. It doesn't take a lot of 38 rounds before 357's start to want to hang up dropping in the chambers. In short, I agree, it's an issue. When I want to shoot soft target level ammo and other 38 level stuff, I solve the problem by using my S&W M67 - it's a 38. It's a really fun gun to shoot, but I digress . . .

You quoted an array of load data using Hornady XTP bullets. Do you plan on using XTP bullets? If not, what bullet do you intend on using?

It can most certainly be done. Keep in mind that if you use 38 case data in a 357 case, the extra case space will result in lower pressure and likely a more inconsistent burn than if it was loaded in the intended 38 case. TiteGroup is probably a good choice here; as it's spunky, high energy, and ignites easily. It seems to be well behaved where there's lots of empty case space (which is ironic, since it's so dense and has such a low fill rate).

Trailboss will likely be mentioned by others for this task. It's super fluffy and is designed to fill the case for consistent burns. I recently purchased a bottle (9oz. - which completely filled a "1Lb" container) and loaded one batch of 38's. It went well I guess. But that's neither here nor there. Point is, I don't have enough experience with it; but I bet others will mention it.

If you're going to go down this road, I suggest starting with 357 load data and work down from there; rather than using 38 data. I'm of the school of thought that you are still loading for 357 Magnum. You're just downloading them. You are not loading 38 Special. I believe that is the way to approach it. It's okay to view 38 load data to gain some reference knowledge; I but wouldn't load to it.
 
I have 38 Special brass and don't bother to reload them. I've always reloaded my 357 brass down to 38 spec target velocities. Expect no crud ring when using faster burning powders for the purpose. My preference Win 231. Although I seldom use Alliant's Bullseye. It's another appropriate powder for the same purpose. (Both powders are reasonably clean burning.) Can't say that about Unique and other equivalent powders.
 
I've always reloaded my 357 brass down to 38 spec target velocities
Me too.... Although my goal is around 1000fps out of my .357s -- that's were the chronograph comes in! All I shoot is 158g SWCs now. Not a fan of 'light' bullets like th 125s. My goto load is currently 5.5g of Green Dot. 5.0g Red Dot works too. I've found many loads that will work. Trail Boss loads are not one of them as far as I was concerned. This is the 'beauty' of reloading... You can load your .357 case from very mild to very wild and somewhere in there is a load that 'works for you'.

Sorry no experience with jacketed .357 bullets. But as stated above you can start on the high side of .38 special loads and work up or down according to your tastes and of course the 'accuracy' and consistency of the loads.
 
Last edited:
I adhere to a rule that I use the brass that matches what is stamped on the barrel. I only load "target" level loads for smaller 357s, typically 5-shot. I do that using the range between 38 Spl +p and 357 minimum where I find them using a common powder. I don't have good luck with magnum powders loading them to anything below max. One like 2400 is more forgiving. Mostly I use HS-6 for larger guns and my remaining supply of SR4756 for the rest. BE-86 is what I would recommend for mild to wild loading with one powder in 357 cases. The midpoint between 38 Spl +p and [.357 less 10%] is 6.2 gr with a 158 lead bullet. I would work in that range to find good accuracy.
 
Last edited:
Both of my Bill Davis revolvers are 357mag. I shot 231 powder and 160g semi wad cutters out of them for years. Both guns will shoot a ragged hole at 25 yards and the 231 burns clean enough that it's never a problem with crud rings, etc. I've taken the same guns and loaded them with full power 357mag loads and shot a pile of deer with them over the years. That 1/10th of an inch of extra case isn't going to do anything harmful unless you load the lightest of "book" loads for 38spl in 357 cases...and then I'm not sure it would be a problem. I've known a lot of shooters who shot thousands of rounds a year this way and never had a problem. I lost track of how many thousands I've shot over the years. Just don't keep going down to see how low you can go, sooner or later you'll find bottom.
 
I have shot thousands of mild 38 specials out of my 686 with no build up. Just keep the gun clean and you should have no issues. 38 special brass is far easier to get than 357(range pickups). I also have a mdl 10 so having ammo to cover both guns is very convenient.
 
Thanks for all the replies.

44AMP – I do have books for load data…2 of them, which I normally use to check and verify the load data I get from the Hodgdon site. I have not experienced the carbon ring in my gun (Ruger GP-100, 6” barrel) because I have never fired a 38 spec cartridge in it. I have experienced the carbon ring problem in other .357s I have fired. I’m thinking it would be easier to avoid the problem.

NoSecondBest - I’m guessing the .357 cases loaded light would hold up to more reloadings because there would be less stress on the case itself. I have lots of .357 cases on hand from frequent trips to the range. Surprising how many shooters don’t police their own brass. What do you use to clean the carbon ring?

Nick_C_S – I do not have a chronograph…probably my next shooting accessory purchase. Also, I’m wanting lighter loads for plinking and practice, while saving heavier loads to carry while hiking in the woods. I’m thinking practice with the same platform used for home defense. NO, I do not use reloads for HD or SD. I have used the 125gr XTPs, but switched to the 140s because the gun performs better with them at near full loads. I will probably try both with the lighter loads. Haven’t gotten into lead yet because the XTPs are readily available.
 
NoSecondBest - I’m guessing the .357 cases loaded light would hold up to more reloadings because there would be less stress on the case itself. I have lots of .357 cases on hand from frequent trips to the range. Surprising how many shooters don’t police their own brass. What do you use to clean the carbon ring?
I don't use anything special. I use a wire brush and Shooters Choice bore cleaner. It loosens everything up quickly and it's no chore at all to get it out completely. It was recommended to me years ago by one of the best shooters in the country and after trying it, it's been all I've used since then.
 
Any .38 Special load works just fine out of .357 cases. Loaded 148 grain HBWC's with 2.7 of Bullseye in .357 cases for eons.
The carbon ring is more lube mixed with carbon than just carbon. Usually only seen with cast bullets in .38 Special cases. Goes away with .357 cases, but it comes right out with no fuss with one pass with a .45 calibre brush anyway. Only matters if you want to shoot .357's right after shooting .38's. Really isn't a big deal.
"...I have .38 Special brass..." In a big pile just like mine? I think mine are in a shoe box. Several hundred at least.
 
38 special brass is far easier to get than 357(range pickups).


First thing I did when starting to reload .357 Magnum was order 500 pieces of brass. I just got another order from Starline with no wait. I will use Winchester range pickups, but the rest get sorted by head stamp and set aside. I learned to scrap any PMC as too soft, too many at least not holding their shape during reloading and then failing the gauge.
 
mgulino,

The answer to your question can be unbelievably complicated.

First, Mr. O'Heir is correct. You've misread or miscopied the .38 Special data. 4.3 to 4.6 grains is the load range at Hodgdon for that cartridge.

The main worry about the ring is not carbon, it's lead. If you shoot lead bullets, especially with quick powders, there is a tendency to gas cut the edges of the lead bullet base and have it splatter and build up in the end of the chamber. Indeed, you can get this even in .38 Special chambers. Back when revolvers were still common for conventional pistol matches, the armorers at Camp Perry all had special cleaning reamers just for getting the lead out of K-38's and other .38 Special wadcutter revolvers. You can still buy those reamers. In a .357 chamber, the lead from .38 WC's can prevent not only quick chambering from a speed loader, but can prevent the mouth of a firmly inserted .357 from letting go of a bullet easily, raising pressure.

For jacketed bullets, the metal fouling build-up should not be an issue. Just carbon, and the big secret with carbon, if there is one, is to get solvent on it when it is still warm and not yet had time to harden. When you finish a range session, and before you put the gun away, use a small pump sprayer of Gunzilla or Bore Tech C4, then the carbon will mostly just patch out after you get it home. Keep it in a plastic bag in your gun case for the ride home, because you can get carbon-saturated liquid dripping out.

But if you are running into ejection problems due to carbon right there at the range, then sticking with .357 cases is best. I admit that is what I do.

So, then, using .38 formulas in .357 Magnum. In theory, because the .357 case is longer, it should lower pressure. The Hodgdon site used to have 231/HP38 loads for 148-grain wadcutters in these two cartridges. The bigger case was getting more pressure from a lower charge. I suspect that because these bullets are seated deeply and leave very little powder space, the primer was unseating the bullet before the powder burn got fully underway in the shorter Special case. It's so unusual, though, I asked Hodgdon to confirm it was what they had on file from their ballistic tech, and it was. Now they've changed the listing to include only Tightgroup for 148's, and the load is identical because both are seated to the length of a .357 case (not the way they are made commercially, nor would it feed in a model 52, so I don't know what inspired that move). But the old data showed some odd things can happen.

In the main, though, if you use the same crimp cannelure for the same bullet in both cartridges¹, you will get lower pressure from the larger case. QuickLOAD suggests that when you seat your 125-grain XTP in the longer .357 Mag case, you will need to go from 4.3 to 4.6 grains to match velocity (8" barrel) and to 4.9 grains of powder to make the peak pressure match (but velocity will be higher because the greater total gas quantity will raise pressure seen further down the barrel and at the muzzle, so there is more late-barrel acceleration).


¹ Some bullets have two cannelures to hit the nominal SAAMI maximum COL's for both cartridges, the lower one being used in .38 Special and the upper one with .357 Mag. This is because a .38 Special cartridge reaches SAAMI maximum COL with a bullet sticking out 0.395" beyond the case mouth, while .357 Magnum reaches SAAMI maximum COL with a bullet sticking out just 0.300" beyond the case mouth. When you use a 38 Special cannelure or crimp groove in the 357, it comes out 0.095" longer than SAAMI maximum COL, though many .357 revolvers, like Ruger, have a cylinder long enough (1.685" or longer) to accommodate that greater COL, letting you use a bit more powder and get a bit more velocity out of your loads for the same peak pressure. There is a similar relationship involving two-cannelure and two-crimp groove bullets for .44 Rem Mag and Ruger Redhawks and a number of other revolvers have enough cylinder length to accommodate extra long cartridges made with the Special crimp groove and the magnum case.
 
I've had good luck downloading 357 brass to 38 levels and less.

Most of my loads now are 357 starting loads +/- a few tenths. Feels like 38 and they're very consistent. My IHMSA field pistol loads were 140 LFP in 357 brass and a light charge of Titegroup. Talk about a near empty case, but they were consistent enough to knock over the 1/2 scale rams at 100 yards. (I don't use Titegroup anymore, but it does work as advertised)

As long as you're not putting a magnum crimp on your light loads, brass life is excellent. Some of my Winchester 357 brass is over 15 years old and have seen countless loads.

Either way works, but I'm lazy so I like magnum brass. Less fussing with the dies. I even spend the extra money to buy micrometer head seating dies and powder dispensers just to save time and frustration.
 
Unique

My K frame Smith's do just find with WC loads in 38 Special cases. Regular cleaning keeps this carbon ring in remission. Ditto, my Model 29 with 44 Special loads. Being old time, my suggestion is to check out Unique. My most recent 38 Special +P loads were using a 358429 bullet and Unique. Shot them yesterday. Works great. No doubt about lead fouling. Too small hard bullets in a revolver+fast powder will do it. You need a slagging hammer to get the barrel clean. In the old days the bullets with two crimping groves, #358156, were used, by legend, allow 357 loads in a 38 Special case. Don't try it! Bubba may have come up with that one.
 
Last edited:
I've shot about two-thousand .38 specials out of .357 chambers and have not had fouling issues. The .38 Special case has an advantage over .357, which is better ejection of the shorter case with short ejector rods on short-barreled guns. The .38 Special case also has plenty of capacity to load rounds that are ballistically superior to 9mm. I've argued elsewhere that the extra length of .357 cases is useless except in long-barreled guns that can get any additional benefit from the very slowest burning handgun powders. But since I've started loading 140 gr all-copper bullets, I've found the extra .357 case length is useful for these bullets that are about 0.1" longer than 158 gr lead bullets and almost as long as 180 gr.

I also shot about 600 rounds of factory LRN. I will say that stuff was filthy. Because it was 158 gr, the velocity was low and I didn't see much leading. Most of the filth was probably burned lube.

I reload and shoot Berry's plated bullets and they're much cleaner. The only real problems I started to see was when loading them to velocities around 1200fps.

While I have never had fouling prevent the chambering of a round, fouling rings are not exclusive to cartridges that misfit chambers. If you watch the Hickock45 video of the BFR, he has a failure he attributes to fouling in the chamber as a result of not cleaning the gun. I can't imagine he fired many hundreds of rounds of .45-70 before that happened.
 
Last edited:
"In the old days the bullets with two crimping groves, #358156, were used, by legend, allow 357 loads in a 38 Special case. Don't try it! Bubba may have come up with that one."

I guess that must me that the late Skeeter Skelton was bubba. :eek: One of his favorite loads was a very hot loaded .38 Spl. case with that #358156 that by his own admission was what he used as a duty load. I run that bullet in .38 Spl. and .357 Magnums all the time as it's a favorite bullet. IIRC, Skeeter loaded those .38 Spl. loads to closely duplicate the old 38/44 load used in the S&W Heavy Duty and Outdoorsman revolvers. They were the predecessors to the .357 magnum and worked very well. Using those loads, IIRC 11.5 gr. of 2400 and the #359156 bullet in my Outdoorsman way back in 1959 I took a Black bear with one of those hot .38 Spl. loads. They work just fine today in my current Outdoorsman 6.5"and in a S&W M28 6".

Do I recommend then in a standard .38 Spl. revolver today. Not only no but hell no! My point is they can be extremely useful when fired in a proper .357 Mag. with slightly less recoil and usually very good accuracy.

The S&W 38/44 Heavy Duty and Outdoorsman were just plain old .38 Spl. revolvers on 44 frames, the "N" frame we all know and love. ;)
Paul B.
 
Back
Top