41 or 40 Gas Checks?

[lar45]

Hi everybody. A friend of mine wants to get started in casting for his 41 mag and 10mm.
What do you guys use for gas checks? The 416?
tks

[ku4hx]

Generally speaking, nominal cast boolit 10mm/40 cal diameter is .401". 41 Magnum is .411". Is your friend planning on using the same boolit for both cartridges and planning on sizing a .410"-.411" boolit down to .401" for the 10mm? If that's true, I think he's going to have a bit of trouble making that great a reduction in size.

All my 10mm/40 cal molds are plain base. I don't load for .41 Magnum but it seems the 416 works.

[lar45]

No, not the same bullet. He's been looking at the Mountain Molds design program. So it looks like I'll try and steer him towards a plain base for the 10mm if there is not a gas check for it.

[ku4hx]

No, not the same bullet. He's been looking at the Mountain Molds design program. So it looks like I'll try and steer him towards a plain base for the 10mm if there is not a gas check for it.

Oh ok ... I was just unsure.

[leadman]

There are two sizes of gas checks for the 41 cal boolits. The original older boolits take a smaller check available only from Gator checks or Blammer here. Some of the newer molds are cut for the 416 check. He'll have to ask what check the mold is cut for.
The Saeco molds are the only production molds now made that I know they take the older gas check. The custom molds could take one or the other.

[runfiverun]

i have seen three different 41 cal checks.
two for the revolver and one for the 416.
dunno about the 40 but i'd imagine that one of the 41's would/maybe/might could work.