loading .38spl loads in .357mag cases

[lykoris]

nothing turned up on searching here that answered my question so here goes


I want to use .357mag cases as

1. I have lots of them
2. the .135" shorter case of the .38 makes for more cleaning of the cylinders

Why I want to do this ?

It is for a 2.5" colt python....I dont want to run .357 mag rounds through it given the apparent risk of the timing failing(pawl takes the recoil) and it's my first python....so I'm being careful. I can get a 686 to use/abuse.

I also don't want the recoil of .357mag with only a 2.5" barrel.

only interested in using VV, specifically N-320 with a 158grain SWC/WC - copper plated bullet.

I think in giving all the information above you guys have a good idea whether this will be possible

my VV manual lists n-320

6.2 - 6.6 grains for .357mag with 158grain HP bullet

and 3.3 - 3.8 grains for .38spl. with 158grain SWC.


putting 3.8 grains in a larger case of the .357 has me concerned due to the higher capacity and although n-320 is a fast burning powder it might not be consistent given such a small amount will simply line the bottom of the case. I have also read it is not recommended to use a filler to pack powder down near the primer. I think this is a no go to begin with....just discussing it to get opinions.

similarly in goes against wisdom in manuals to start below the min. recommended load so for example with .357mag....taking 5 grains rather than 6.2

I would really appreciate some feedback .

Thanks ...sorry for the long question

 

[SASS#23149]

1st off, you are comparing lead loads with jacketed bullet loads,not a good idea as they are far different even when using just .357 or .38 data...jacketed takes more power to get the bullet out of the barrel.
for plated bullets,most mfgrs. reccomend lead-load velocities as you may know.do you know if your bullets are rated for jacketed velocities?
what velocities do they show for the lower end load? I"m sure the fps will be much lower in a snub nose as most loads in most books are not tested in snubs.

 

[rcmodel]

Look at the Cowboy Action load data:

http://www.lapua.com/index.php?id=1196

4.5 grains should give you a nice 850 FPS .38 Special power level load with 158 grain plated bullets in .357 cases.

rc

 

[Walkalong]

N320 & 357 cases

4.3 Grs N320....X-Treme 158 Gr SWC....666 FPS ...4" barrel (686)

5.0 Grs N320....Zero 125 Gr JSP....738 FPS ...6" barrel

5.3 Grs N320....Zero 125 Gr JSP....898 FPS ...6" barrel...822...2 1/2" barrel

5.4 Grs N320....Berrys 125 Gr TrFP....969 FPS ...6" barrel...886...2 1/2" barrel

5.4 Grs N320....Berrys 125 Gr TrFP....1033 FPS ...6" barrel...904...2 1/2" barrel
(More crimp)

3.8 Grs N320....Berrys 148 Gr DEWC....675 FPS ...6" barrel

This may help. Check charges in load books. Start low and work up. You know the drill. be careful.

N320 works well in .38 Spl.

 

[lykoris]

Many thanks for the replies guys

SASS, I realized that but as it is a 2.5" barrel it was less of a concern - lead/jacketed bullet.

rcmodel,

I was hoping you would add something as it is always interesting to read your posts - extremely impressive amount of knowledge reading your various posts on the reloading section.

walkalong,

that is data I will definitely hold onto, one thing about VV manual is the 6.5"(.38spl)/7"(.357mag) barrels they tested their loads in & the no doubt optimum conditions. I think the other 6 manuals I have are more 'realistic' in terms of what people shoot across calibres.

Many thanks for taking the time to write it out Walkalong, I will be putting it to good use as I would like to go with lighter bullets also down the road in 125grain.

I think I will start at 4grains of n-320 and do a lot of 20 for each .1grain up to 4.5 while observing for pressure signs in between shooting lots while seeing how they do on the chronograph.

Thanks again to you all, you have been of great assistance in giving me an idea of where to start from.

 

[Oyeboten]

Ironically...the .357 Cases would be ideal for Black Powder...and in a long Barrel Revolver, would allow a heavier than usual Lead Bullet (180 or 200 grn, say,) to gladly pass the 1000 fps mark...


Really, far as I can tell, the .357 Magnum WAS the 'last' Black Powder Cartridge Case to have been offered...Lol...

 

[ArchAngelCD]

The data above from Walkalong looks like it's all you will need.