38 special and 357 mag factory duplicate load ?

[rebs]

I have been trying to find a factory duplicate load for 38 special and 357 mag with a 258 gn jhp bullet and bullseye or unique powder. Can anyone help me out ?

[gwpercle]

Are you sure you are looking for 258 grain bullet data? What bullet are we talking about?

[Nick_C_S]

Assuming you meant a 158 JHP.

Still leaves me (us?) a bit confused as for what you are looking. Factory loadings rarely (if ever) use "cannister grade" propellants, like Bullseye or Unique. And even if they did, they would keep that information proprietary.

Ammo manufacturers buy their propellants in bulk, and don't necessarily match up to anything being sold at the retail level. Duplicating factory ammunition would be a difficult task. Emulating factory ammo is a more practical endeavor.

Hope that sheds a little light on the subject. More detail would be helpful to proceed further.

[rebs]

MY bad, yes I meant 158 grn jhp's. What I am looking for is a load that will be close to a factory load. I sometimes CC there two guns and want to do some practicing with loads that are comparable to factory loads.

[sawdustdad]

I seem to recall that .357 factory loads could be approximated with 2400 or W296, those two generally will give top velocities for that round.

I'm not much help on the .38spl. Seems like Bullseye would get you close.

Do the boxes of factory ammo have the velocity on them? I'd find load data that came close to that.

I wonder how close you need to really be for practice...I doubt that in a SD situation, you'd ever recognize a difference in recoil through the adrenalin.

Or just practice with the factory ammo???

[T. O'Heir]

Your manual should/might have a factory duplication load listed. Oddly my old Lyman book has it for a 158 grain cast, but not a jacketed bullet.
However, Hornady lists their MV as 1250 fps for an xtp, so any powder that gives that will be close. HS-6 gives around that with mid-range loads according to Hodgdon's site.
Of course, you cannot get the powders any manufacturers use.

[Nick_C_S]

I'm still curious specifically which factory loads you're talking about.

I have a number of factory load "emulations" for recoil practice with 158 grainers. I might have additional information if I can be pointed in the right direction.

[rebs]

I am interested in factory equivalent loads for 158 gr jhp's in 38"& 357 mag calibers for use in a j frame 2 inch barrel and a s&w model 19 with 4 inch barrel. I believe the bullets are Winchester.

[Snyper]

The first thing you have to do is determine the velocity of the "factory load"

Then any load you come up with that comes close will give similar performance.

The particular powder will make little practical difference

[Nick_C_S]

In Winchester's Super-X line, they make a 158 JHP that muzzles at 1235 fps through a 4" bbl. One thing about factory defense ammo, is that they tend to use slow, flash suppressed powders.

I've built a round that emulates this. Using a 158 JHP and 11.2g AA7 (in compliance with Speer #14), I'm getting 1272 fps through a 4" bbl. I'm sure this round behaves very similar to the Winchester Super X.

[rebs]

Thank you for the help,
Nick I don't have that powder. Maybe I can find some.

[Nick_C_S]

8.2g Power Pistol runs at 1174 fps (in compliance with Speer #14) is also pretty close.

[44 AMP]

Oddly my old Lyman book has it for a 158 grain cast, but not a jacketed bullet.

Probably because a lot of those "old Lyman books" were printed before the factories began loading jacketed bullets in those calibers.

My 45thEdition Lyman (1970) is like that for the .38 and the .357.

That book, for the .38 Special 158gr Cast, w/gas check #358156 #2 alloy
Factory Duplication load 3.5gr Bullseye powder. 826fps. THIS IS THE MAX LISTED for that powder & bullet!!!!

Same bullet, .357 Magnum, factory duplication load
Herco powder, 11.6gr 1388fps. This is a compressed load, and THIS IS THE MAX LISTED for that powder & bullet!!!!

This is old data, and I present it for information only. USE AT YOUR OWN RISK!