I changed to seat and crimping in separate steps for that very problem. I use a Lee factory crimp die to crimp

I have one of those that came with my 300BLK dies from Lee but I wasn't able to get it adjusted right. The first few didn't crimp enough but when I adjusted it down it wrinkled the shoulder of the brass. Like it crimped and still pushed down on the bullet or the neck of the brass. Infuriated me because Blackout brass i.e. Expensive or time consuming to produce. I am not that happy with Lee dies and my last three caliber so have been Hornady New Dimension dies. Around $40 on sale and 100 free bullets which I usually get the .308. Factor $6 for shipping and you still get $14 worth of bullets. So the dies end up being $26 and are much better quality than Lee.

I am going to reload a batch of BLK soon so I will watch what I am doing with that factory crimp die.

According to Midway, the 300 Blackout FCD is a collet type rifle die.
https://media.midwayusa.com/producti...120/456506.jpg
The rifle FCD is a whole different animal than the pistol FCD. The pistol FCD is a taper crimp die with a "post sizing ring" that insures the loaded case is within specs.


I have rifle FCDs in many different calibers, and it is about the most idiot-proof die ever made. If it is dimensioned correctly and working correctly it is impossible to crush a case, or even to over-crimp, because the shellholder should be pushing on the collet, not on the case. Once the fingers on the collet close, that's as far as you can push the collet into the body.

Take a shell holder, a case, and the FCD and try this:. Put the case in the shellholder and insert the case all the way in the FCD by hand. Does the shellholder contact the collet, or is there brass visible between the shellholder and the collet?

I promise.... I won't mention the use of mercury in doing an absolutely perfect job of cleaning out lead from a barrel. I won't say a word about how mercury amalgamates (bonds) with lead and causes it to dissipate in just a few minutes.

This not said... Mercury is a dangerous element, and can cause health concerns if not handled properly. Since most people would not know how to handle it properly, I will not suggest its use to clear lead from a barrel, even if it was in common use as little as 30 years ago.

Just "not" sayin'
Michael

Based on your Santa post, I'm pretty sure why your FCD die is not working right.

If you are forming brass from 223, and not reaming or turning the necks, then your necks are way too thick, preventing them from going into the collet. You are essentially turning the FCD die into a conventional crimp die, as which it would work very poorly if at all.

Try some factory 300 BLK brass, I'll bet you get a completely different result.

To crimp the thick necks you might be able to spread the fingers of the collet a little.

Had some success and some failures on Sunday, I am still busy cleaning guns and haven't had time to write up how it went. As soon as I can I will update.

I see what you mean about the Lee Crimp die and will also check that out with factory and cut brass.