FCD Questions

[BR]

What is the difference between a Lee FCD and either the Dillon or Lee taper die in 9mm? Why is one better than the other for 9mm, particularly when loading 147 grain bullet?

Yes, I've read every post in response to a search for "FCD." I know people some people believe it is great, others believe it is not necessary or even detrimental when loading 9mm, yet no post really explains what is different between a FCD and taper crimp die and/or why one is better than the other for 9mm or other calibers.

On another note, I recently have had bullets tumbling with 2 different glocks, stock barrels, and 3 different loads. What are the potential causes of a bullet tumbling? Thanks.

-br

[rhyrlik]

The Lee FCD differs from other crimp dies in that it has a built-in carbide sizing ring just like a sizing die. This ring sizes the case as you crimp. With straightwalled rounds like the 40 S&W or 45 ACP and lead bullets the use of the FCD is detrimental because it swages down the bullet being held inside the case. This reduces the bullet's diameter and lessens case tension. It also induces leading.

The 9mm Parabellum, however, is not a straightwalled case. Its base is some .010" greater in diameter than its neck. The carbide ring of the FCD, therefore, does not touch the case neck or the bullet sitting in the case. There are no issues with the FCD and the 9mm.

[rhyrlik]

Bullet tumbling, especially with plated bullets, is sometimes caused by overcrimping. Too much crimp causes the case mouth to cut through the plating and for some unknown reason to destabilize the bullet in flight. I don't understand the mechanics of this process. Common sense indicates that it should not matter. The jacket is plated to the core, but it does.

[revchuck]

While the FCD does have a carbide ring, it's not the same dimension as the one in a sizing die. AAMOF, I've read that it was created originally because Lee had some oversize carbide rings for their sizing dies and didn't want to throw them out, so they came up with the FCD as a means of using them.

The carbide ring on the FCD is there to ensure that all loaded ammo is to minimum SAAMI specs to ensure it loads in any chamber. This being the case (no pun intended), if you use slightly large cast bullets and load them in relatively thick brass, you can have a situation where the bullet is squeezed down a tad. I've had this happen to me with .38 Special/.357 Magnum and .45 ACP, using, respectively, .358" and .452" cast bullets in both Winchester and CBC (Magtech) brass. I've never had a problem in .40 S&W with any brass, though I haven't used .401" bullets...yet. I've switched to a Dillon crimp die for .38/.357 and gone back to a standard taper crimp die for .45. If I weren't so danged lazy, I'd sort my brass and use the appropriate die.

Also, while 9x19 is a tapered case when factory loaded, current carbide dies are straight. This is why reloaded 9x19 that was formerly loaded relatively hot will show a step or ridge at the bottom of the case after sizing.

[el pres]

To Revchuck, pirate post Ahhrrrr, nevermind I changed it !!

Anyhow, in dealing with my little bullet problem today (see earlier post) I tried

to get my FCD to size my bullets but no luck. I guess if you had overly "thick?" brass it could happen

but the carbide sizer ring on my .40 FCD is .415ish, it did'nt change the sizing of the bullets at all.

An FCD does narrow down the brass as a last step and greatly increases the case guage "pass" numbers

of your finished rounds.

As for tumbling rounds ?? I'm not sure but most the time this happens it is from overcrimping or because the

bullets are coming out of a Glock !! No, really, if your using lead bullets, Glock barrels tumble certain

lead bullets. I dont know if it's a sizing problem or what, someone else will be able answer that but changing

bullet brands may help ??? Acually I even remember someone saying something about changing a Glock barrel out

for a convetional rifiling to shoot lead bullets ???

Edited August 18, 2008 by DIRTY CHAMBER

[rhyrlik]

but the carbide sizer ring on my .40 FCD is .415ish, it did'nt change the sizing of the bullets at all.

So you claim that you can squeeze a round measuring .423" in diameter through a carbide ring measuring .415" without sizing the bullet? Can you please explain the magic involved?

[el pres]

but the carbide sizer ring on my .40 FCD is .415ish, it did'nt change the sizing of the bullets at all.

So you claim that you can squeeze a round measuring .423" in diameter through a carbide ring measuring .415" without sizing the bullet? Can you please explain the magic involved?

It's a magic die ???

Brass is resilient ??

How to do you think you get that hourglass shape in the middle section, like my avatar ??

Alright, .419ish , it's tampered... Well it does'nt size the part sticking out of the brass and thats what I need right

now ,ok Just joking got my own bullets problems right now. All I know is people always want to blame the FCD

but I've shot thousands of Plated Berry's, Black Precisions, and Lead with no tumbling through any gun ??? Go figure ?

all loaded with an FCD..

Search Polyagnol Rifiling and tumbling bullets !!

Edited August 18, 2008 by DIRTY CHAMBER