Seeking suggestions for .38 Super cast.

[Kosh75287]

My "dream gun" is finally in my possession. It is a Tanfoglio Witness in .38 Super. Both the pistol and caliber handle j-word projectiles just fine, but I want to develop a "general purpose" cast bullet load for it, with the following constraints:
1.) As-cast weight 135 gr. > 160 gr.
2.) Configuration should be SWC or RNFP. In the case of the former, a meplat that is as wide as possible is preferred.
3.) The projectile should be capable of being driven fast enough that its weight x velocity > 168,000.

I'm open to suggestions about as-cast diameter, and I am entertaining the notion of polymer-coating. I'd PREFER not to have to invest in any elaborate/expensive equipment for sizing and (conventional) lubing. I know that greater diameter TENDS to help accuracy, but can often impair performance due to elevated chamber pressures. I welcome and am grateful for everyone's most thoughtful recommendations.

[lar45]

You might consider slugging the barrel or doing a chamber cast to see what dimensions you are dealing with.
A chamber cast of a semi auto pistol barrel is very easy to do.
The Lee 358-125 and 158 RF look like good options as long as they don't drop oversized.
I have read that many guys use a .358" cast bullet in their 9mms.
I have also read that many 9mm barrels have groove diameters of .357"
Hodgdon's load data shows that both the 125 and 158 should meet your velocityxbullet weight requirements.

[BC17A]

3.) The projectile should be capable of being driven fast enough that its weight x velocity > 168,000.

I'm open to suggestions about as-cast diameter, and I am entertaining the notion of polymer-coating. I'd PREFER not to have to invest in any elaborate/expensive equipment for sizing and (conventional) lubing. I know that greater diameter TENDS to help accuracy, but can often impair performance due to elevated chamber pressures. I welcome and am grateful for everyone's most thoughtful recommendations.

My 38S Witness barrel slugs at .3558" and I size at .357". I cast the same boolits for it as I do for 9mm, 120TC, 125RF, 125RN and the 105SWC. Looking through my reload DB I have a few warm-ish 125 grain loads that nearly hit 163,000. The 147XTP's that I've loaded for SD top 167K so I'm sure that PC'd heavies would easily meet your 168K criteria. The Witness is a tank and should be able to take a lot of punishment. As for a mold, I've been eye-balling the Accurate 35-148K which should be a good choice for 38S.

[Kosh75287]

As usual, I received only excellent advice from those who answered, and I am in debt to both of you. Thank you very VERY much!

BC17A, between the time I posted, and received my first reply, I read with considerable surprise, that USPSA rules for "Limited" class (where it seems an unmodified .38 Super Witness would be classified) preclude the use of .38 Super for "Major" scores, as it is not .40 caliber or larger. The .357 SiG gets a pass, and CAN be scored as "Major" if the PF is enough. NOT SO, the .38 Super, for some (as yet unrevealed) reason. With heavier projectiles, the Super can develop PFs > 165k with some room to spare. The SiG round works better with lighter projectiles and suffers with the heavier ones.
A request from USPSA for clarification and the rationale for such a quirky rule elicited a response amounting to "We don't really know why, but we're looking at changing it."
I like the suggestion for the Accurate 35-148K, and I'll look into it more seriously. If the rules don't change, it should be easy to work up a 900 f/s load to use for competition, and one that does 1150 - 1200 f/s, for social work.
Thanks, both of you, for the input.

[nueces5]

a friend of mine uses a 38 super for ipsc in open division
He told me that it is difficult for him to get a good accuracy since he always has a shot that goes out of the group
I made some linotype boolits with the rcbs 124 cn mold and I made two pc
had better results

[Bigslug]

You want meplat?

My preferred 9mm medicine proved to be the NOE/Ranch Dog tumble lube 135 grainer:



It casts at .357" and works well for me swirled in 45/45/10.

The Accurate 35-135D is effectively the same bullet and the mold can be custom ordered to your spec diameter and alloy.

[Thin Man]

I am trying to recall that the Lyman 358480 mold pattern was created to satisfy the need for boolits in the Super 38. I use this 2X mold for my Supers and am very fond of the results they give me. While claimed to generate a 133 grain boolit, my alloy must have more lead and less additives and throws 138 grain pills. My sizing diameter is .357 and experimented with .358 with no significant difference found in either group size or reliability.