RCBS 223 Rem Trim #8.
This is file type trim die for the 223.  I full length resized with Redding die.  When I try to change over to the RCBS trim die, the cases stick inside the die.  The neck will insert easily from the top end, but when the case goes into the full die it sticks hard as the shoulder as the case engages toward the top.  The neck is not close to the top as it binds.   I even tried lubing the case, but it still sticks.
Any ideas.  Is this not really a trim die?  This is the first time I'm trying this die.

I use a rcbs rotary trimmer.

Might get more responses if you post this in the reloading subforum.

I, too, use an RCBS rotary case trimmer.  Lyman's EZ hand trimmer kit with rifle pilot set is cheap and works well.  You can chuck it up in a hand drill for higher volume.  Never used trim dies, sorry.

When doing some dabbling in trim dies, I had read that some companies trim dies are made to size-die dimensions, with a little looser neck diameters.

The die i used was made by Redding, and they claimed they used CHAMBER dimensions for their trim dies.

Not sure what RCBS uses. If they use size-die specs, then you are probably "sizing" your brass twice.

Would be interesting to measure your brass after running through the Redding size die vs the RCBS trim die, and see how they compare.

Wouldn't hurt to reach out to RCBS and tell them whats going on and see what they say.