Working up factory like .357mag rounds

[Macross]

Ive worked up a fairly good load for general target and practice shooting. Its fairly civilized to shoot and is economical enough to make to not worry too much about shooting a bunch of it off. 5.0gr APS450, 158gr SWC TigerShark projectiles.

I would like to try and make up some more factory like rounds that have a fairly heavy punch to them. Letting mates try out my target rounds really doesn't give the full .357 magnum experience, and having to shoot $1.00 - $2.00 per shot factory rounds can get expensive.

My guess is I will most likely have to look at different powder, but not sure which ones to check out. Anyone have a good recipe for some factory'ish loads.

[wanneroo]

For 357 Magnum power you'll need to go with H110, IMR 4227, Winchester 296 or Lil Gun. Looking at the ADI chart, AR 2205 is the closest powder to those.

It can be fun shooting those lighter loads or 38 Special but also like you say, sometimes you want the full experience.

With the above powders, it's pretty straightforward as I recall. I don't have my chrono data at hand at the moment.

[No1Mk3]

G'day Macross,
The SAAMI standard for 158g is 1240 fps so 6.2 of AP70 will run 1250 or 14.0 of AR2205. If you should happen to find some Win 296 NEVER reduce the powder load that Winchester recommend (they issue a warning to this effect on their data) Cheers.

[rc42]

Without access to a chrono to work up the best bet would be to load rounds using the maximum in the ADI loading guide (which is still somewhat conservative)
For 158gr SWC that is listed as 5.2gr for APS450

You might get better results with slower burning AR2205 which reduces the initial pressure peak and burns longer so keeps increasing the speed of the projectile as it travels down the barrel, For that powder 16gr is the maximum recommended and I've tried that load myself with good results, it was similar to warm factory round so could probably go a little higher.

For either powder you can work up in very small increments until you get the bang and recoil you are looking for but having a chrono is strongly recommended.

[Macross]

It can be fun shooting those lighter loads or 38 Special but also like you say, sometimes you want the full experience.

Yes... the OMG followed by the chuckle kinda experience.... I dubbed my 4" 686 the giggle cannon after my mate giggled like a school girl after firing it for the first time.

[Blr243]

I loaded up some hot 125 s in my old smith once I can’t remember the charge but they were brutal And uncomfortable

[Macross]

I tested some rounds yesterday with the AR2205. Low side ADI data said 14gr with high side 16gr. I made some at 14gr and some at 15gr. I noticed unburnt powder and some sooting halfway down the outside of the case. I think i may need to go for a tighter crimp.

Some google'ing suggests 0.5gr higher may alleviate the soot??? Im fairly happy with how hot the rounds are at 15gr for that full on .357 magnum experience. Not overly keen to push it to much higher.

[Gamerancher]

2205 is notorious for leaving unburnt powder. A tighter crimp helps but it will still do it.

[Macross]

Ive just been using Federal Small Pistol primers. Wondering if i should be using magnum primers???

[Gamerancher]

I get a bit of "soot" on the cases in my 686, ( although I don't run hot loads in it ), not really a problem, that's what tumblers are for.

[rc42]

16 grains of AR2205 pretty much fills the 357 magnum case and I find the small pistol magnum primers work better as the larger ignition penetrates through the large volume of powder faster.
That should reduce the unburned powder and will also increase the initial pressure so should help the brass case to expand and seal the chamber enough to stop soot on the outside of the case.

You would be best to go back to 14 grains and work up again as the magnum primers are equivalent to having more powder from a peak pressure point of view.

[wanneroo]

Magnum primers are what you need.

[wrenchman]

I have been working up loads for my Henry and my gp100 I have just started using h110 and spear bullets i got them just before covid I am still on the low side of the loadings but it is because I am having a hard time getting to be range or property every time I try our governor shuts the state down.