I am not totaly new to reloading, however i find the more i learn the less i know. That being said i have 500 mt new 357 brass, and 125 grain Xtreme copper plated bullets, with a choice of Titegroup or HP-38. On recommendation from Xtreme bullets, they said use Speers published data, but keep on low end of scale for jacketed rounds. I did and used 7.6 grains of HP-38 , with a small primer @ 1.580col minimal lee crimp die. This is the minimum listed and works fine but seems a bit hot for target practice. (manageable out of a 6" 686, but hurts out of a snubnose) I do not yet have a crono so could not get a speed , but book says 1129 fps, well under 1300 fps recommended for plated bullets. My question is can i use 38+P load data in a 357 case and at what end of the scale? I do know that case volume has a lot to do with pressure and am not sure if 38+p data is even viable. Ultimately i am trying to find a light target load for my 357 brass, that is not at magnum velocities. Any recomendations would be appreciated.
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38sp+P loads in 357 cases
- Thread starter SK1911
- Start date
buck460XVR
New member
I would start either @ max for .38 or somewhere in between the .38 max and the .357 min you have tried already. How do the minimal loads with W231/HP38 compare to factory .357 ammo or even factory .38 special ammo? How do you know the load you have now is "a bit hot for target practice"?
Yes, you can use 38 S. +P data in 357 M. brass. The velocity listed for the +P loads will be higher than what you'll get from the loads in 357 brass. If you are just paper punching and have no need for Magnum loads, just use wadcutter data, in the upper levels for 38 S., in 357 brass. I've been doing this for years...
Keep it simple
I think you're making this more complicated than needed.
If your 7.6 grains of W231/HP-38 is a bit sharp for your liking/application, simply reduce the powder charge. No need to get all wrapped around the axle regarding +P load data, using a 357 case, yadda yadda yadda. Over thinking. Just turn it down.
My question is can i use 38+P load data in a 357 case and at what end of the scale?
I think you're making this more complicated than needed.
If your 7.6 grains of W231/HP-38 is a bit sharp for your liking/application, simply reduce the powder charge. No need to get all wrapped around the axle regarding +P load data, using a 357 case, yadda yadda yadda. Over thinking. Just turn it down.
Thanks for the input. Common sense would seem to dictate all things being equal there would be no difference using 38+p load data in a 357 case as the firearm shoots both. However there are numerous warning out there about using to little powder in larger cases ( flash over). This was my concern, but on looking at Hogdons load data they list a 357 LRN at 5.5 grains with 1185 fps and a cup of 18800. So i would think that using about 6 grains would be a good starting point for plated flat points. side note 7.3 grains hp-38 shows a cup of 33800. at 1335 fps. The only difference is the bullets themselves and as stated in the original post im using plated flat points, which is not listed by Hogdon or any body else. Simple is always better, but safety is always first.
buck460XVR
New member
I think you're making this more complicated than needed.
If your 7.6 grains of W231/HP-38 is a bit sharp for your liking/application, simply reduce the powder charge. No need to get all wrapped around the axle regarding +P load data, using a 357 case, yadda yadda yadda. Over thinking. Just turn it down.
I agree, which is why I suggested starting at the max for a standard .38 load with a similar weight/profile bullet. While it may be max for standard .38, it won't be in a .357 mag case and thus should give less recoil than factory .38 or .38+p. Problem with downloading any ammo is that accuracy generally suffers when you start going below starting loads.
A light target load for my 357 brass is any .38 Special load. Been loading cast and swaged 148 grain WC's with 2.5 of Bullseye in .357 cases for eons. Works just dandy.
+P is a pressure thing. Not velocity. You can forget +P altogether. Hasn't anything to do with what case you use.
7.6 grains of HP-38 is going to hurt out of a snub nose. It's a jacketed .357 load running a bit over 1335 fps. Use cast data, not the jacketed data.
+P is a pressure thing. Not velocity. You can forget +P altogether. Hasn't anything to do with what case you use.
7.6 grains of HP-38 is going to hurt out of a snub nose. It's a jacketed .357 load running a bit over 1335 fps. Use cast data, not the jacketed data.
Common sense would seem to dictate all things being equal there would be no difference using 38+p load data in a 357 case as the firearm shoots both.
Well, not exactly. The 357 case is some 130-ish thousandths longer; thus, all else being equal (bullet, powder charge, primer) the round assembled in the 357 case will likely deliver less pressure when discharged. The extra internal volume slows the burn rate and reduces peak pressure.
The two rounds will be apples n oranges. Which is why I mentioned in my first post to not overthink this. Just turn down your existing load by reducing the charge weight. Disregard 38 Special data (+P or otherwise) and work on adjusting your existing load. HP-38 can turn way down before becoming problematic. The possibility of a stuck bullet won't come into play until you're velocities are quite a bit below 600 f/s for jacketed - even less for lead (all this is assuming a healthy functioning revolver).
As far as flashover goes, I believe that's a rifle thing. I've never heard of such a phenomenon in straight walled pistol cartridges. Not to completely dismiss; as anything is possible of course.
+P is a pressure thing. Not velocity. You can forget +P altogether. Hasn't anything to do with what case you use.
Well stated.