O ring & die question

[madmixerman]

When using an O ring under the die ; how do you maintain a consistent shoulder bump with a F/l die ? How is this achieved from one loading session to the next?

 

[DeadEyeDick45]

I assume you are referring to the Lee Dies which have a O-ring under the locking ring. I solved the problem on my LLM by exchanging entire turrets with the Dies remaining positioned and not removed.

 

[bigedp51]

My dies have O-rings under the lock ring and I use Redding Competition shell holders. When the die makes hard contact with the shell holder and the press cams over these shell holders control the shoulder bump. When the O-ring is used the die can float and self center in the presses threads. And because I have an older Rockchucker press from 1973 the Competition Shell Holders remove the slop from the press and variations in shoulder bump.

You asked about a "constant" shoulder bump, all you need to do is switch brands of brass or switch from new brass to older brass and the word "constant" goes out the window. Meaning there is always some form of "tweaking" to be done to get the desired bump or shoulder setback.

Many people use reference marks on the die and press to maintain a set shoulder bump. And this is to ensure the die is not rotating. And if you Google "O-rings under the dies lock ring" you will find a wealth of other information.

 

[madmixerman]

Thanks.