Hornady decapper pin won't drop down

Berdan primed brass with no center flash hole?

Seater/crimp die being used as the sizing/decapping die??

Bottom line is.
Make sure you got the right die in use.
Take the decapper assembly out of the sizing die and see what you can see up in there.

rc

The decapping assembly should not float under reasonable pressure. If memory serves me correctly, the Hornady decapping rod is designed to allow for quick adjusting. Once the nut is lose, you can slide the rod up and down easily.

The decapping pin should extend about 1/4" or 3/16" out the bottom of the die. Far enough to knock out the primer but not too much for the pin holder to contact the base of the case.

After setting the position of the decapping assembly, the nut on top of the die must be tightened to grip the decapping assembly.

By "smashes the neck", do you mean the mouth of the case is damaged or there are dents in the shoulder.

Dents in the shoulder are caused by excessive use of lubricant getting it on the shoulder of the case. Damage to the case mouth, I do not know at this point.

Hope this helps.

Do you have the instruction sheet?

The decapping pin will move up and not work when it encounters a primer if the "Zip Spindle Lock" is not tightened after adjusting the spindle so that approximately 3/16 " of the decap pin is below the end of the die.

OK, it sounds like yo need to get the decapping rod out of the die. With the nut loose, the rod should screw out the bottom of the die if the nut does not release the threads.

Maybe something is stuck in the die. Maybe the expander ball is the incorrect one, probably too large.

Hope this helps.

It looks like the expander ball might be stuck in the die, possibly with a case neck around it.

The expander ball with a case around it will not fit in the area of the die that resizes the neck.

Depending on your level of comfort, you could take a small diameter punch and try to remove the obstruction tapping from the top of the die.

RCBS has a die repair service for their dies, I would suspect that Hornady does as well. But I do not know for certain. Check with Hornady.

I you have not done so, look for a cross section cut away of a bottle neck cartridge resizing die to see what the inside should look like ant the relative position of things inside the die.

I do not have a rifle set of Hornady dies but I have a set of pistol. It looks like your decapper came off of the threaded holder, that I do not see in the photo and pressed in the cavity. You should have a piece that is about twice as long as the die, and it screws into the die, and into the decapper that you have stuck in the die. Do you have more parts? I think the rifle and pistol are the similar. Hope this makes since as I am typing as I just got my second cup of coffee....