Homemade .357 Mag
Below, I’ve listed the load that I currently use most in my revolver. It’s a very mild load (more 38SP +P), “sub magnum”. It is however very enjoyable to shoot and accurate in my Colt.
Disclaimer: I take no responsibility for the correctness of this load data, use it as theoretical reference only.
- Cases recovered from factory ammo (mostly GECO)
- WSP – Winchester Small Pistol Primers
- 158 gn LOS FP (copper plated bullets)
- 6.5 gn Vithavuori VN340 (using the .71cc Lee auto disc)
Somewhere on this site, you can find a Lee disk volume-weight cross reference table which can be used as a starting point for building your loads. I’ve recently started testing with Vihtavuori 340 which is not listed in that cross-reference, so I’m listing 2 volume-weight reference points for it here.
VN340 is a slow burning handgun powder, which I use for reloading .357M. It’s known for burning clean, being reliable and consistent and for being on the more expensive side. Where I live I pay about 130€/kg for VN340, good old HP38 comes at 99€/kg. Add to this that you typically need more VN340 than HP38, e.g. comparable loads for .230gn 45ACP with VN340 list about 1.2 times the weight of HP38. So if you do the full the price comparison VN340 is about 1.58 times the price of HP38 (again, that’s where I live).
VN340 is extruded powder (small cilinders) which in my experience, VN340 meters very well in a Pro Auto-Disk Powder Measure. The loads I’ve built with it have been extremely accurate.
Reloading is serious business and one should not forget that.
The reloader’s biggest fear is generating overpressure in the chamber when firing a cartridge. Overpressure can cause the gun to break (blow up) with a variety of consequences. Personally, I’m on the cautious side meaning that I don’t “hunt” for +P loads and I work up loads from minimum load data and my reloading process is tuned as much as possible for safety. Still, no-one is free from mistakes, one can only attempt to avoid them. Actually currently I also simulate my loads and check the effect of variations on powder charge and seating depth. I’m keeping pressure 15% off maximum SAAMI pressure.
But risks sometimes come from the outside… At some point in time I got some 9mm reloads from an experienced reloader. The picture shows how the cases came out of my Browning Hi-Power after firing. Clearly these were too hot for the gun and a possible safety hazard, luckily I noticed early and only fired a few rounds.
I’ve written about the issues with the Lee Adjustable Charge bar (ACB) that I had and the solution to this problem. In my case, I only found out that it didn’t work for me AFTER buying it. However, if you are still looking for an adjustable power thrower for your Lee autodisk powder measure, I came across this clever solution (cf. rugerforum):
I have not tried it, but it seems a valid option. I’m just wondering if you don’t get into trouble with inconsistency with respect to powder getting stuck on-top of the screw (and falling of one time and not the other) and the cavity below the screw.
I’ve found these tables cross-referencing lee autodisk volumes with powder weight (in grain) on the internet somewhere. I’ve found these to be pretty correct. BUT use this data as starting reference only, always verify the actual load dropped (there might be errors in the table, there is variation of humidity changing weight/volume, maybe a powder composition changed, etc).
With a progressive press or turret press, one has to rely on mechanical powder dropping droppers to reload efficiently. I have the Lee Classic Turret with the Lee Pro Autodisk, and I’m very happy with it. With ball powders the Autodisk system works perfectly, it throws consistent loads reliably. However there is one problem: the fixed loads you are limited too.