[F. Guffey]

Uncle Grumpy, ‘O’ type press “I have been reloading for a few years now, I have been using my fathers O frame press bought in the early 70' “,

As you can see, without knowing the brand of the ‘Old ?’ O frame press it is a guess, in the beginning before Internet reloading a distinction was made between ‘CAM OVER’ and cram, jam or lock up presses, In the beginning RCBS presses ‘cammed’ over, now they jam over, meaning they jam/cram up before the ram reaches the top (top dead center), a cam over presses reaches TDC and starts back down, the amount of cam over can be measured by a few reloaders with a feeler gage, most deny it happens. In the old days the die was adjusted to the shell holder on a cam over press, the cam over amount, in the old days, was called ‘Bump’. Bump, today, means anytime the shoulder of the sizing die contact the shoulder of the case it bumped. I suppose ad in bumped into the shoulder like some kind of accident. To find ‘Bump’ before the Internet, read RCBS die instructions from 1960 +/- a few years.

Back to RCBS and bind-up/lock-up, the linkage gets tangled up at the bottom when the ram is raised to the maximum, the linkage hits the bottom of the ram, when the linkage hits the ram the ram is kicked forward at the bottom and back at the top. Do not panic, a compulsive giggler posted the effect on YouTube, there was no die and no case, meaning? The case in the die prevents the kick out at the bottom, after the posting the ‘usuals’ posted the claim blaming cheap manufacturing on China and or other countries.

then there is the problem with being able to determine if your press is a ‘cam-over press’, there are not many Herter presses I do not have, all my Herters are cam over presses, two are guaranteed not to flex, with common sense the amount of cam over is a designed limiter to bump.

Back in the old days I listened to a lot of stuff that did not make sense, when sizing and or forming I scribed lines at the case body shoulder juncture, scribing the line convinced me the shoulder of the case did not move, the line did not move, the shoulder was being erases and formed someplace else, I also found by scribing the location of the case body shoulder cases were not stretching between the case head and case body, it was interesting to me part of the shoulder of the case became part of the case body and part of the neck became part of the shoulder, back to stretch and insipient case head separation, insipient case head separation comes from bad habits, not firing the case. Anyhow, I became a fan of knowing the length of the chamber first then sizing cases by length to off set the length of the chamber, I became a fan of cutting down on all that case travel.

Receivers, like presses have different designs, one rule does not apply to all receivers, one rule does not apply to all presses. Again, What brand of press are you using?

F. Guffey