Lee Factory Crimp Dies

[Macca]

Hi guys,

I've never used a lee FCD die until now. My dillon 650 is set with redding dies in all calibers.

I recently got given a lee FCD for 9mm....figured I might as well set it up and try it as so many people seem to have it as their final die...but I'm honestly not certain I can see what it is doing that the redding dies aren't already achieving beforehand. My case neck comes out of the redding crimp die at exactly .380 which is exactly what I want my 9mm case mouth to measure. Maybe the FCD performs a greater function when used with lee die sets?

If its serving some other purpose that I'm not enlightened about please let me know?

[Jman]

Essentially it's just a second resizing die that crimps the bullet. Many good people swear by them. When their set up right they work well. I used

then for several months myself. I came to believe that if you need the thing to produce reloads that function you're neglecting something

fundamental in the precess. Sold mine and haven't looked back.

[98sr20ve]

If you take a regular Sizing Die and size a case you will see it sizes the case to well below SAMMI spec.

If you take a FCD and size a fired case you will see it sizes the case to just at SAMMI spec.

So if the rounds are under sammi spec the FCD will not make a measurable change to the brass. ANY sizer is always sized below the size it is sizing too. But thats another discussion.

[at_liberty]

In the context of 9mm, I use the FCD to remove the burr along the edge of the case mouth. Regular crimping doesn't do that. Under magnification, I can see the before and after and set it up to leave a light, uniform taper at the edge of the case mouth. All I am doing is feeling the cartridge and wanting a finger nail to catch but not pick up any snag or roughness that could affect feeding. I also have more confidence that the bullets will stay put, but always get an argument when I mention that. It is more a matter of my confidence than any technical distinction. I want that finished edge.

Note that my bullet seating die is set to do no crimp, only remove the flare. If I crimp on both operations, the later FCD will cause the case to collapse, producing scrap, I guess due to the existing tension at the case mouth.

[Rob Tompkins]

Most resizing dies I've seen (and I suspect all) have a taper where the case enters the die so the die does not resize all the way down the case. With some brass that has been shot in a gun without a fully supported chamber (e.g., Glock 40 S&W's) there is a slight bulge towards the base of case that the sizer die can't remove because of taper at the opening. FCD sizes all the way down to the base of the case and takes out this bulge.

I found the FCD to be very useful for 40 S&W. I just started reloading 9mm and I've been using one but I've not tried not using it. So, I've not yet reached a conclusion if it’s needed or not.

[BillD]

I reload .45 on a 650 and use the LFCD. I had one pistol that was tight chambered and a 625 that you had to chamber check each

load.

It fixed both of those issues. I very rarely even case gauge anymore. I wouldn't be without it. Reloading is not my hobby, shooting is. I just want vast quantities of shooting ammo with the minimum of fuss. The LFCD helps me achieve my reloading goal.

[MoNsTeR]

I used FCDs from very early on, and never really thought twice about it, basically buying into the Lee marketing. Then someone convinced me they had the potential to hurt accuracy by sizing bullets down, and/or reduce neck tension due to the differing elasticities of lead and brass, so I gave them up and switched to regular taper crimp dies. Then I noticed my chrono results changed noticeably, and did a head-to-head test. I don't know for sure if the FCD affects accuracy or neck tension or reliability, but it cut my SDs by 40%. Now it's my taper crimp dies that are shelved.

[470nitro]

I started using FCD in .40 using alot of range brass from police shooting Glock pistols.

Before the FCD, I had a Dillon sizing die and my ammo ran OK but I would lose maybe 3%-5% of my cases on a case gauge due to the final 1/16"-1/8" of the case due to the bulge.

At that time, I looked online and couldn't find a direct reference to a Lee "U" undersize sizing die so I call ed Lee to ask them about it.

The tech I spoke to told me that, just as Rob Tompkins said above, that nearly all sizing dies have the taper and won't size down close enough to the base of the case to take the bulge out. He told me that the right fix was to use the FCD. So I bought one online.

Trying it, my fallout rate on the bulge (from the same brass source) dropped to well under 1%. Enough that I don't even think about it. I also don't crimp, I just barely straighten out the case flare as I don't want a true crimp. Like Brian Enos says, the case diameter provides all the tension you need.

I like mine but I use it more for "final sizing" the base of the case more than for real crimping.