RCBS Lube dies, Why 1,2,3,4 holes in them

I'm getting set up to start lubeing with a LAM2 and getting my dies in, I've noticed that dies come with varying number holes in them.
I would asume that rifle dies that are going to lube multiable groves would need more holes but my lyman 358 die has 4 sets of holes and the 357 boolits are small by comparesson and only have a single grove so why so many holes.
I also remember reading here about pluging the extra holes with lead shot, Is this correct and how do you determine what holes to seal off ?

Thanks in advance for your help, Steve

You are correct, lead shot. 7 1/2. For a single lube groove, leave the bottom open and plug the top ones. If it were a 2 lube groove, leave the the bottom 2 open, and so on, and so on.

They recommend shot for a Star sizer, but that’s a different species from a LAM. A pistol bullet usually doesn’t need to go past the first hole. Line up that lube groove with the first hole and it will be completely sized, at least that’s my experience.

There are rifle bullets in 358 that will require the deeper holes.

No need to plugs the holes of RCBS/Lyman dies, the machine linkage is adjustable allowing you to fill the grooves you want fill.

The 4 holes evenly spaced around the die are for ease of filling the grooves, it requires less pressure on the lube plunger
to distribute the lube and will do it faster than one or two holes.

I have yet to see an RCBS H&I die with more than 4 holes but Lyman H&I dies have 4 vertical
rows of 2 to 4 holes each. As stated above you don't need to plug holes to lube single lube groove boolits.

Good to hear all this, I learn so much from this site.
My replacement parts arrived from RCBS today [smilie=w: and now i can replace the O-ring seal, fiber washer and retaining clip and fill it up with Ben's red and learn how to use it.

I'm sure to have more questions soon.

Thanks, Steve