I haven't done a lot with the 401452 Boser SWC in the 10mm, but as I recall, I tried 3 different powders (HS-6, HS-7 and Red Dot? not absolutely sure, the computer holding those records crashed). I was sizing those bullets .401" (because that was the only suitable sizing die I had at the time)

A couple of comments on the poor accuracy I obtained from these loads.

First, this mould drops bullets that are about .405" diameter. Sizing them down .004" might have contributed to the poor accuracy (especially with this particular sizer die, which is an old one and shaves bullets as much as it swages them).

Secondly, the S&W 610 that I shot those loads in has .400" throats. Some revolvers tolerate oversized bullets, some do not. Those bad groups (4-5") could have been an indication that this particular revolver does not like oversized bullets.

Thirdly, those tests were run very early on in my experimenting with the 10mm in the 610. While HS-6 and HS-7 are good powders for the 10mm, I have since found that Accurate Arms #9 is the powder to beat in the 10mm. I didn't try the Boser SWC with AA#9.

Bottom-line is, that bullet might shoot well in the 10mm, I'm not sure that I've really given it a fair shake.