FCD without cannelure in J-Word bullets

[Animal]

Hey folks,

I'm in the process of loading my first rifle rounds. I'm using the Lee Pacesetter die set for 7.62x39. This set does F/L size and provide the FCD. Right now, I'm just in the 'dummy-round' stage of the process.

Now, Lee claims that the provided FCD will provide the bullet with its own cannelure, and crimp the brass sufficiently within the 'cannelure' that is provided by the FCD.

I'm trying to load these rounds so that the final COL is as long as my magazine will allow, and so far all the rounds chamber properly.

Right now, "bullet set-back" upon chambering is my biggest concern before proceeding. I don't want the COL to change during the cambering process. I've adjusted the die an additional half-turn (after following Lees instruction on initial adjustment). I am now at a point where bullet set-back is almost eliminated. I still see a change of 1-2/1,000 after remeasuring the chambered round. I feel much better about this, but I'd like to eliminate that as well.

When I pull the bullet with my kinetic hammer, I see a pretty obvious deformation from the FCD. Now, Lee tells me that this is what the die is meant to do, but I can't help but wonder if this is too much? Is it a problem? Can it cause excessive chamber pressures and result in damage to the rifle? or injury to myself?

I reread the section about the FCD in Lees manual and reread the instructions that came with the die set. I did not see any warnings about applying too much crimp.

What are your thoughts? is half a turn on top of the instructions too much? or is this normal? Thanks guys.

[timspawn]

I use the instructions that come with the die and have been happy. I would say as long as you don't see signs of over pressure and it does not affect accuracy you should be ok.

[Animal]

Thanks Timspawn. I went ahead and finished the first batch of test rounds. I'll post my results soon.

[Stoats]

It's fine. It's the only die that permits a nice crimp on e.g. Sierra MatchKings for use in a semi.

[DR Owl Creek]

Redding makes taper crimp dies for use on many bottle-neck rifle cartridges. I prefer them to the Lee FCD dies. They provide a more uniform crimp than Lee's collet type dies, and don't work the brass so much so you shouldn't have split or cracked case necks so soon. I use the Redding taper crimp dies for all of my gas operated semi-autos now, and have gotten rid of the Lee FCD dies. Here's a link for the Redding 7.62x39mm taper crimp die: http://midwayusa.com/product/737623/redding-taper-crimp-die-762x39mm .

Dave

[Maximumbob54]

The neck tension should be enough to hold the bullets. The Lee FCD doesn't need to be used so hard that you see four raised ridges in the case mouth. That will quickly destroy the case.

[dkf]

I don't deform bullets with a crimp, never saw how that would be good in any case. The FCD can be used to just remove flare and that is how I use them the vast majority of the time. I do often ad flare to help seat the bullets better especially on cast. In a magazine fed semi I am more concerned about the bullet moving front than back. Have not had any issues thus far.


Redding makes taper crimp dies for use on many bottle-neck rifle cartridges. I prefer them to the Lee FCD dies. They provide a more uniform crimp than Lee's collet type dies, and don't work the brass so much so you shouldn't have split or cracked case necks so soon. I use the Redding taper crimp dies for all of my gas operated semi-autos now, and have gotten rid of the Lee FCD dies. Here's a link for the Redding 7.62x39mm taper crimp die: http://midwayusa.com/product/737623/...p-die-762x39mm .

Dave

Thanks Dave. Next time I need a crimp die I will look at them first.;)

[Animal]

Dave, I'll look into that as well. I played with neck tension a little, but I was never satisfied. My OAL would change once the round is cycled into the chamber, not by much, but enough to irritate me. Also, I have some concerns about a bullet accidentally setting back further into the case if the action wasn't cycled flawlessly, so what I saw with only using neck tension bothered me.

So far, things are going well with the rounds. I'm getting significantly better grouping than with factory ammo. I've only tested half way up on the charge data so far. Hopefully I'll have even better results as I test the last batch of rounds.

And yes, the crimp I spoke of did give me some concerns about brass life. I don't plan to load these too often, so it is a price I'm willing to pay... at this point anyway.