Cowboy Action Light Loads for .357 Mag cartridges - PRIMERS Standard vs Magnum?

[LUBEDUDE]

I'll be using the Starline 357 brass I bought at an auction. Ya gotta save $ where ya can, right?

Understood, and you’re going to love CAS! A lot of good, helpful folks. Watch, listen, and learn from the veteran cowboy shooters.

But unless you are talking about thousands of 357 cases, you’ll switch to 38s. When? That depends upon your learning curve and frequency and duration of participation.

[charlie b]

FWIW, I have always used std primers in my light .357 loads. Most of those are .38spl or .38 +P level loads. I only use mag primers if I am shooting heavy loads.

Why not use .38 cases for light loads? I just never had good luck with the longer bullet 'jump'. If I were to want a weapon for light loads only I would try to find a .38spl chamber.

[gpidaho]

I think Steve's goal here is to use what he has on hand and what he has come by at a steal of a deal. Sure, there are a million good 38spl loads and an equal amount of good 357 ones. With what you have on hand Steve, I would use the 700X and there's no need that I see for a magnum primer unless a friend gave you a few thousand of them. In that case use them, it won't hurt anything. Gp

[sniper]

Steve: 5.5gr Unique/150 gr RCBS cast boolit/4" barrel /357 brass/standard primer=~860 fps chrono'ed. 4.5-5.0 gr. Unique should get you right about where you want to be.
I've never thought it is an advantage to use .38 Spl. brass, unless, like Skeeter Skelton, a person could get it free. With mild loads, average brass cost should not be a factor. Good luck!

[35remington]

Try chronographing light to moderate loads of Unique in 357 cases with powder near bullet then powder near primer.

Expect the disappointing results you will get.

[SteveK]

I think Steve's goal here is to use what he has on hand and what he has come by at a steal of a deal. Sure, there are a million good 38spl loads and an equal amount of good 357 ones. With what you have on hand Steve, I would use the 700X and there's no need that I see for a magnum primer unless a friend gave you a few thousand of them. In that case use them, it won't hurt anything. Gp

GPIDAHO, You pretty much understand my situation perfectly. To me, its all a matter of trying to live with what I have ...safely, without damaging my stuff. Shooting store-bought 357MAG rounds through my Cimmaron Evil Roy pistols really beats the hell out of the pistols [not to mention my hand], but not so much the knock-off 1873 rifle. Also keeping in mind the safety issues presented by ricochet rounds or lead splatter made light loads a must for me. This was my first venture into CAS. If I was to start all over again I'd have probably looked harder into acquiring/reloading 38 SP ammo or maybe 45 LC (which also seems to be super popular among the folks where my shooting events are being held.) Oh well, live and learn.

Just the same, I'm very grateful to you folks for all your help. Thanks a bunch!

[SteveK]

Try chronographing light to moderate loads of Unique in 357 cases with powder near bullet then powder near primer.

Expect the disappointing results you will get.

I'm afraid you lost me making the distinction between "powder near bullet" vs "powder near primer." I can't see how to force either situation in a cartridge case.

[35remington]

Tip barrel steeply down. Level. Fire.

Tip barrel steeply up. Level. Fire.

Expect horrid results over chronograph. 38 Specials are bad enough. 357s are worse. This models handling variation of the gun. Putting farty loads in 357 cases with Unique is synonymous with extreme velocity variation.

[SteveK]

Ya know, after I though on this for a bit I guessed that this is what you meant. Clever test! Oh well... as long as they come out of the barrel straight velocity variation might not matter very much... From what I've seen, all the targets seem to be less than 20 feet away. I guess cowboys weren't very good shots unless it was an ol' Winchester '73. Thanks for splainin'.

[SteveK]

Steve: 5.5gr Unique/150 gr RCBS cast boolit/4" barrel /357 brass/standard primer=~860 fps chrono'ed. 4.5-5.0 gr. Unique should get you right about where you want to be.
I've never thought it is an advantage to use .38 Spl. brass, unless, like Skeeter Skelton, a person could get it free. With mild loads, average brass cost should not be a factor. Good luck!

Thanks sniper! I'll give a little heavier load a try. When it warms up a bit, I'll take the chrono out to the range and see what they do.

[35remington]

I’ve seen some cowboy shoots were 50 yard shots were required. They don’t all have to be big and close. If they are not, give some real thought to using more consistent loads than lowest possible pressures with partial casefuls of poorly suited powders.

[Finster101]

.38 Special brass just makes a .357 harder to clean. I prefer not to deal with the carbon ring.

[SteveK]

I’ve seen some cowboy shoots were 50 yard shots were required. They don’t all have to be big and close. If they are not, give some real thought to using more consistent loads than lowest possible pressures with partial casefuls of poorly suited powders.

Holy smokes! I've never seen such a long shot in Janesville CAS events. Well, I won't give up looking for a better match loads. Thanks!

[35remington]

Here at the Columbus NE range such a thing was at the state shoot a few years ago.

[sniper]

Trailboss also comes to mind. Good case fill. I got caught up in the "The Minimum load that will make your gun go Bang" madness a decade or two ago. There was this article in one of the gunzines which recommended reducing your standard load (in my case, Unique) by 50%, then doing it again. I did, which lead to a little boy at the range asking his Mom; "Why is that man hammering on his gun?" as I was knocking the stuck boolit out! It seems that I have seen the same guy, or one of his disciples on YouTube..."SHOOT your gun with 2.7gr Unique!"...or some such. I haven't bothered to watch!

[smkummer]

.38 Special brass just makes a .357 harder to clean. I prefer not to deal with the carbon ring.

I have experienced this with revolvers but that is over time and if they were not cleaned each time after shooting. I am going to keep an eye on my new to me 1996 Marlin 1894C. My test for my 357 revolvers after shooting 38 ammo and cleaning is if a 357 drops into each chamber easily.

Anyway Lee’s 358-125 RF runs perfect in my gun and at 10 yards is a tight group standing. I only fired 15 rounds and a 357 chambers easily so I’ll have to see after a 6 stage cowboy match and 60 rounds if my cleaning is adequate. Also, in my situation, I have to use 38 special brass in order to fit 10 rounds in a 18 1/2” barrel rifle for cowboy action.