Lyman O-Mag Ram Movement

[Lord Kimbote]

I recently purchased a nice Lyman O-Mag press, which I believe is dated to around 1980. It has what seems to me to be an unusual linkage compared with my Lee Classic Turret, and it is somewhat perplexing.

With my Lee press, when I move the ram handle all the way down, the ram moves as far up as it can go (a full stroke). With the Lyman O-Mag, when I move the ram handle down, the ram moves up until about 95% through the stroke when it moves back down about a half of an inch vertically as the handle is completely down (a full stroke).

I took the ram linkage apart, and I don't see another way this ram can work, so I assume this is how it was designed. Am I correct in thinking that the only way I can use the press for precision tasks (e.g. bullet seating) is to screw a die down so far that the ram will contact the die before the full stroke is completed?

 

[rcmodel]

screw a die down so far that the ram will contact the die before the full stroke is completed?

No. Don't do that.
It would be less precise then letting it do what it is doing.

The press is doing what is known as "toggling over", and it is perfectly acceptable.

It is just as precise at full stroke as any other press with a handle stop.

All the way Up is All the way Up.
And if the linkage went past top-dead-center and started back down?
It was as far Up as it can possibly ever get.

And it will be exactly repeated every press stroke.

rc

 

[Lord Kimbote]

RCmodel,

Thanks for the info, but I am still somewhat confused as to the best way to set a die. You are saying that I should allow the ram to make a full stroke, which means it will rise and then slightly fall. To set a die, should I then find the highest level that the ram will go and set the die to touch the ram at this point? I have found that to be somewhat tricky.

Thanks again.

 

[243winxb]

Upstroke vs downstroke Lyman Spartin press.

http://i43.photobucket.com/albums/e366/bohoki/spart2.jpg And http://i43.photobucket.com/albums/e366/bohoki/spart1.jpg Not your press, but 2 ways to use the linkage. Might help?

 

[Lord Kimbote]

243 Win,

While not specifically addressing the movement of the ram, I still appreciate any information about these older presses. I had never considered reversing the movement, but I may look into that as I have a really cruddy table that wants to tip over when I put my shoulders into moving the press arm.

Cool pics.