2 questions about 38spcl / 357 magnum

[Charly]

I was at the range last Saturday and a shooter next to me was asking some advice about his reloads. He was shooting a Marlin Lever Action 1894C in caliber 357 mag. / 38 spcl.


He was experiencing a strange phenomena shooting 2 differents bullets with the same loads data at 50 yrds. Shooting 158 RN was very satisfactory in grouping but the same load with 158 SWC was totaly out of groupe and even bearly on the paper. (the load was VV N340 6.0 grs.) . Would the bullet type make such a difference ?
Same guy was telling me he is using 357 mag brass to reload 38spcl . What would be the load data to refer to ? Just look at the 357 mag and use it with standard SP primers ? Or start with 38spcl data and build up ?

[cohutt]

1- don't know
2- Use the 38 special data in the 357mag brass, no problem. Same principle as loading 44magnum brass with 44 special data for my plinking "cowboy" loads.

[Glooooock]

A round nose 158 .38 is one of the cleanest pistol bullets made ( BC . 215 in one book ) .

[Charly]

- using the 38spcl data in 357mag brass I guess I can start at max.load because anyway I less pressure building up (more space), rigth ?

- round nose 158grs maybe cleanest but would that really make such a dramaic difference in accuracy with the SWC ?

[Glooooock]

Yes , more space / lower pressure but a slow burning powder needs enough pressure to burn completely . At longer ranges it would be bullet related - short range issues would be powder charge ,,, as far as bullet group sizes.

Is this cast or jacketed bullets ?

The book shows 158gr .357 VV340 at 6.6 gr out of a 6 " pistol at 1,182 fps . It should be faster out of a rifle .

[Charly]

Is this cast or jacketed bullets ?

they were both commercialised lead bullets (not jacketed)

[Glooooock]

It might be a bit fast -1500 ? , or just bullet sizing / quality issues - lube . One bullet might have more side contact ( bearing area ).

[Charly]

well, I am using the same SWC shape as he had and I have no problem with the grouping...
I don't know if it is the same make, probably not !

[dougader]

Were both of the bullets hardcast lead, or was the lrn a softer swaged bullet? That can make a difference with Marlin's micro-groove barrels.

Lots of people have complained that Marlin's MG barrels don't get good accuracy with hardcast lead.

Otherwise, it could be as noted above that diameter of the two slugs was different enough to cause such a drastic problem with accuracy.

[Charly]

I don't know about hardcast or not , we didn't get that far into the discussion.
And I must admit my knowledge doesn't go that far either .

But the guy did tell me something about a diameter difference bewteen the two bullets type, so that goes towards that issue probably.