Using 38 Special components in 357 Magnum brass

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arcee

Bearcat
Joined
Nov 9, 2014
Messages
32
Whenever you choose to step out of "published loads" ie using 38 special load data in a 357 casing you are going to have to consider what you are doing.

For openers, you will be loading considerably lower than the minimum "published" charge weight. Can this lead to squibs? Yes it can. Can this lead to double charges if you are not careful? Yes. Can this be practically and safely done by an experienced reloader? Yes, it is done all the time for various reasons.

I reload and shoot a Super Redhawk in 454 casull. I use cast lead boolits and "cowboy" loads designed for the 45 Long Colt in the full length Casull casings. This is to avoid a powder ring build up with the shorter Colt .45 cases.

The pistol becomes a soft shooter with these loads and is very accurate within cast boolit ranges. Am I conscious when of watching for squibbs? Yep, but after a few thousand rounds, I am pretty sure of my load. Do I pay attention when reloading that I am not "double charging"? Yes, I promise that double charging with fast pistol powder if VERY BAD.

BOTTOM LINE: In my opinion, you can safely reload .357 brass using 38 Special data. It is also best to use the 357 brass to avoid developing powder rings in your cylinders and minimizing the bullet jump to the pistol throating. Downside is your velocity will be lower than the published 38 special data because of the casing volume.

I am not advocating anyone reloading shells outside of published load data. I am saying that experienced reloaders will sometimes reload to their objectives rather than use the published data. It does violate one of the first and most important reloading rules (especially for new reloaders) which is to ONLY LOAD published data.

v/r arcee
 

kmoore

Buckeye
Joined
Mar 29, 2017
Messages
1,323
Location
Idaho
On the internet we just don't get much of a perspective of what all is being asked, why and is it by someone who knows really what they're doing. Anyone can respond with what works in their gun. And I agree if it does it will likely be fine in theirs also. But will it.
I worked up loads in a 30-30 win Ackley improved with almost no data for a post 64 94 I still own today. I will not share that data. I was using my chronograph, but it was still a little scary. My dad had a Savage 30-30 win in a pump action. He had his chamber made into a Improved also. My loads did function fine in that rifle also and I started low working up a little.
I was working up loads for my 7mm wby mag last year. Following all data down to case and primer. One book was under max. another over max powder charge. I had fired about 20 rounds using that data. Loaded another 20 to get a 300 yd zero. first 2 were fine, 3rd shot the stock broke forward and rear of the action mounting screws, and the bolt would not open. I spend hours attempting to find out what happened. The case had split just above the belt. For sure it was over pressure but why. All remaining cases had bullets pulled and were the same charge I had been using. The brass was on it's 6th reload, maybe it was just worn out. I tossed all other brass had been loaded more than 3 times. And reduced the load. No problems since.
Last fall, I switched from standard primer to mag primer with a mid range powder load in a .308 win bolt rifle. The idea was to see if impact would shift, if not I might use the mag primers when deer hunting in freezing temps. First shot was over pressure, the bolt was stuck closed. At home I got the bolt opened and the primer was pushed out of the pocket. Firing pins may break when this happens but it was fine.
Point being accidents can happen. Be safe as possible when making your own.
 

Hvymax

Blackhawk
Joined
Nov 30, 2022
Messages
904
Location
Maryland
Whenever you choose to step out of "published loads" ie using 38 special load data in a 357 casing you are going to have to consider what you are doing.

For openers, you will be loading considerably lower than the minimum "published" charge weight. Can this lead to squibs? Yes it can. Can this lead to double charges if you are not careful? Yes. Can this be practically and safely done by an experienced reloader? Yes, it is done all the time for various reasons.

I reload and shoot a Super Redhawk in 454 casull. I use cast lead boolits and "cowboy" loads designed for the 45 Long Colt in the full length Casull casings. This is to avoid a powder ring build up with the shorter Colt .45 cases.

The pistol becomes a soft shooter with these loads and is very accurate within cast boolit ranges. Am I conscious when of watching for squibbs? Yep, but after a few thousand rounds, I am pretty sure of my load. Do I pay attention when reloading that I am not "double charging"? Yes, I promise that double charging with fast pistol powder if VERY BAD.

BOTTOM LINE: In my opinion, you can safely reload .357 brass using 38 Special data. It is also best to use the 357 brass to avoid developing powder rings in your cylinders and minimizing the bullet jump to the pistol throating. Downside is your velocity will be lower than the published 38 special data because of the casing volume.

I am not advocating anyone reloading shells outside of published load data. I am saying that experienced reloaders will sometimes reload to their objectives rather than use the published data. It does violate one of the first and most important reloading rules (especially for new reloaders) which is to ONLY LOAD published data.

v/r arcee
It doesn't take much power to get a bullet clear of the barrel. Even a double wiff charge shouldn't hurt anything.
 

crstrode

Bearcat
Joined
Jun 23, 2012
Messages
92
Location
Badger Lake, WA
This was a eye opener. This may help. Seating depth and PSI. If you load 38sp in the mag case I think the extra volume may come into play for good or bad? On the left, seating just a tiny bit more .062 doubled the PSI.
View attachment 14887
Very interesting info. What is the source of this diagram? I also notice that the crimp grooves are all unused - even in the "normal seating". Additionally; 1/8" is 0.125", not 0.062". This leads me to suspect the data may be bogus as well.
 
Joined
Dec 11, 2002
Messages
8,122
Location
Ohio , U.S.A.
having actually seeing 'detonation' of 2 grains of Bullseye in a 148 gr wadcutter load in a few different guns back in the day all I know is that "Murphy" was an "optimist", me, I am a "realist"...............now I know what Wil meant........:rolleyes:

"....and so it goes....Wil Terry " may he rest in Peace;)
 

arcee

Bearcat
Joined
Nov 9, 2014
Messages
32
This post is NOT meant as a Highjack. but rather a reference for further consideration of Detonation and Catastrophic failures in our reloaded cartridges. The following is NOT about pistol powder in pistol rounds, but using pistol powders in rifle cartridges.

While this has nothing directly to do with the OPs original question, it is the best source of information I have ever seen on Detonations, Double charging, etc. It must be read and considered.

Before final conclusions are reached about the dangers of double charging and overcharging, we might want to review this site. http://www.gmdr.com/lever/lowveldata.htm. Click on the embedded link titled "The Use of Pistol Powders in Rifle Cartridges" and read the article titled: A Solution - A Solution Rediscovered.

It is roughly the same concept as using 38 special loads in 357 cases. Undercharging can cause unexpected results.

I have been working with the data on the site for more than 12 years in various calibers.
GMDR and specifically the Oregon Trail Cowboy data side of the site.

Before using any of the WEB published load data on the GMDR site, determine whether or not you have the experience to interpret what you are seeing and behave accordingly.

I would recommend reading both parts the article that I have referenced, and if you do not understand what is being said, delete the site. I do not mean this unkindly but double charging is a big risk with these loads and VERY BAD things happen.

I have personally used this site extensively for years but for specific purpose loads in the larger caliber rifles and for sub velocities in .223 and .308. I even used it for mouse farts in my .375 H&H.

It is an interesting site and at least a good read.


v/r arcee
 
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DGW1949

Hunter
Joined
Apr 10, 2005
Messages
3,652
Location
Texas
The difference in case length between a .38Spl and a .357-Mag is a "whoping"(LOL) 1/10".....You'll see more difference than that in where the crimp grooves are situated in different brands of otherwise identical bullets...not saying not to be careful because you should be....just sayin'.
 
Last edited:
Joined
Oct 24, 2007
Messages
11,396
Location
Kentucky
"After-the-boom" analysis of gun explosions cannot usually be certain of the particular reload in question because the evidence just went up in smoke.

"But I swear it was only two grains . . . " Yeah? For sure and certain? Absolutely?

That said, I don't find it too surprising that Hercules' investigation cleared the powder itself of any erratic behavior.
 

Rich/WIS

Bearcat
Joined
Sep 23, 2022
Messages
27
Location
Corbin, KY
Checked my old Lyman manual for several different cast bullets in 38 and 357 and the max 38 load was either slightly above or below the starting loads for the 357. Less than 357 starting loads might be an issue in terms of complete powder burn, squibs, or erratic ignition, but will not be dangerous per se.
 

protoolman

Hunter
Joined
Oct 15, 2001
Messages
2,213
Location
ND
For the guys who say use only published loads I call bs. I have never and I suspect the same of all here....
Seen someone load a cartridge to the exact recipe in the book. You're telling me that you loaded a Winchester small pistol primer ( because you usually only use cci) into a Hornady .38 +p case (oh no the thicker wall will increase pressure!) Instead of the R-P case listed. And you used 40 year old powder ( oh no everyone knows they increased the burn rate of that one!) Then seated a 148 gr sierra swaged wad cutter ( not a Missouri cast butter co. CAST! Wadcutter instead) everyone knows that their crimp grooves are in slightly different places! The point is we ALL make calculated changes. The calculated changes I would make would be to use the top end of the .38 data for .357 cases and everything should be fine. Obviously we all take our chances but there are virtually no known problems reported doing this.
 

Rclark

Hunter
Joined
Jan 1, 2009
Messages
3,369
Location
Butte, MT
The point is we ALL make calculated changes.
+1 . It is called using your head as more than just a hat rack :) .

As the .32 Mag, I don't laugh at the reloading data (good starting place ) but certainly understand it can be pushed a bit and I have :) .
 
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