RCBS Jr2 press

[Beekeeper]

Does anyone know the diameter of the ram?
Have one I have had for 40 plus years and finally saw a little movement (sideways) in the ram.
Want to know the diameter so I cam mike mine to see where the wear is.

RCBS says .997-.998 and mine reads .810 top to bottom so we must be talking about diferent presses cause I surly do not have that much wear.


beekeeper

[462]

My JR3 measures .810", too.

My Rock Chucker II measures .998".

[Pressman]

""I measured the three Jr2 presses I have and all are very tight with the rams measuring .8125” These were taken from a new, unused aluminum frame, a first model, ECHO manufacture and a first model RCBS manufacture.""

Ken

[462]

I should add that the JR3 doesn't have any play.

Edit to add: This thread has piqued my interest to the point that I did some more measuring and wiggling. The ram does have a slight taper to it, measuring .812" at the top, and .810" at the bottom. The ram is a solid fit till it's at it full height, then there is some play. I don't know the criticalness of the play, but I use the press only for M-die expanding, and applying handgun crimp.

[Beekeeper]

462,
Mine is over 40 years old and has had some rough handling over the years.
It reads .810 top to bottom.

Had never given it any thought " should work forever right" until I let my attention wander and saw it give the slightest wiggle.

It is an old friend and I just do not want it to fail.
That is the reason for the question to start with.

Now that I know it is relatively common I will not worry too much.
Just keep it clean and lubed.

Pressman,
is there a specific lube I should use?
Maybe something a little thicker than the gun oil I have always used?


beekeeper

[NVcurmudgeon]

Beekeeper, I had a Jr, I think 2, that I bought new in 1963. In 1988, after about 50,000 rounds, I got a little concerned about the amounbt of ram wobble and wrote to RCBS. Of course I told them that my garage color scheme was almost entirely their shade of green, which was true. I said that I didn't mind buying a new press after so much good service and was looking forward to buying a Rockchucker. To my great amazement they sent me a new RS 3 and a note that said that the new press would fit right in with my decor. The RS 3 is as good as new and is my main press. I never did get around to buying the Rockchucker. The old Jr? My friend in Montana used it more than I did and it held up great until he passed last year. Come to think of it, if the die is in good shape the case will skate aroound in the shellholder no matter how much ram wobble there is. The die will make sure the case is straight. (I have spoken, and don't answer flames.)

[Reverend Recoil]

There is a simple reason the rams are 0.8125". 13/16" (0.8125") is the tap drill for 7/8-14 threads. In making the press it was drilled and reamed 13/16" through and then the top was tapped 7/8-14.