Lee Factory Crimp Die

What is your opinion of the Lee Factory Crimp Die?

  • Works as advertised.

    Votes: 210 91.3%

  • No noticeable difference either way.

    Votes: 7 3.0%

  • Gimmick.

    Votes: 13 5.7%
  • Total voters
    230
rookie wildcat said:
Now, why would that be horse manure? Internal ballistics should be as uniform as you can make them. No matter what may happen with your dies, sometimes the neck tension will vary due to brass thickness and the wear of the die mandrel die body. This can create lower neck tension esp if the neck is only .001" smaller than the bullet used. If you take 10 pieces of brass, and the neck thickness is not standard, then you could wind up with several different neck tensions, each of which allows the bullet to be let off in a different way.
When the primer is struck, the powder is ignited. As it burns, it builds up pressure in the case. If the bullet moves at too low a pressure, then that will affect velocity, which affects accuracy and if the all move at different times, all will have different velocities. Simply by ensuring that all the bullets have the same tension, you can ensure better accuracy.
He!!, that's one of the reasons commercial rounds are crimped in that manner.
Physics can't lie in this case.
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I hate to disagree with that statement but I have to. There is no way that little band of crimp is going to compensate for lack of neck tension ( I have tried it BTW& it was an epic fail). If you take it that you have a difference of neck tension & apply additional resistance via a crimp, I can't see how that would equalize anything. Factors that would contribute to the variance in neck tension ( ductility, variation in wall thickness, etc ) would also lead to a variance in crimp strength.
 
Only to play the devil's advocate, but if a FCD crimp doesnt compensate for lack of neck tension when releasing a fired bullet, then how can it help during violent loading events say in an M14?
 
I have another question about the FCD as well, Lee states that the FCD can be used to crimp bullets that do not have a cannelure, yet it seems that most people recommend not crimping bullets without cannelures...anyone able to shed some light here??

I ask because I'm just getting ready to reload for the first time and it will be for an M14(well M305 actually), and I bought two boxes of bullets without cannelures(I should've looked better before buying) and I keep hearing that rounds for the M14 should be crimped due to the rough action of this auto loading system, soooo do I need to buy different bullets with a cannelure or can I use the FCD on the ones I have now(Sierra Matchkings and Gamekings 150grains)??

Thanks for any help offered and please excuse my ignorance, just trying to make sure that I don't do something stupid.
 
hk33ka1 said:
Only to play the devil's advocate, but if a FCD crimp doesnt compensate for lack of neck tension when releasing a fired bullet, then how can it help during violent loading events say in an M14?
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The crimp die makes a sharp edge on the bullet at the top of the crimp forming a sort of one way valve, the bullet can go forward but not back without completely distorting the brass. If you want to do an experiment, don't resize a case & crimp a bullet in place then try pulling it out. If the bullet has enough surface area you will probably be able to pull it out with your fingers. You can crimp a case without a cannelure but it will distort the bullet.
 
I use the Lee FCD when reloading for autoloading rifles in .223, .243 & 7.62X39. Testing with a chronograph has shown a noticable increase in velocity (and pressure) when crimping bullets in the cannelure (vs no crimp) although I haven't seen a marked difference in accuracy.
 
desporterizer said:
The crimp die makes a sharp edge on the bullet at the top of the crimp forming a sort of one way valve, the bullet can go forward but not back without completely distorting the brass. If you want to do an experiment, don't resize a case & crimp a bullet in place then try pulling it out. If the bullet has enough surface area you will probably be able to pull it out with your fingers. You can crimp a case without a cannelure but it will distort the bullet.
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See, that's the beauty of freedom of religion. You can believe one way and I can believe another, and we all make ammo that we shoot and no one gets hurt...;)
 
Personally, I have seen 3moa ammo become 1moa ammo after being crimped. I load .223 for two different rifles, and in both rifles crimped ammo is more accurate. Exact same primer, powder charge, and bullet used.

I've been meaning to post a thread asking what other people were experiencing, but never got around to it.
 
The Lee pistol FCD CAN size the boolit and case mouth, sometimes in a bad way for those using oversized cast.

The rifle FCD does not have the carbide sizer ring at its base, and does NOT do this.


Iron Sighted I have shot lots of smooth Sierra bullets through my M14 with and without FCD, no problem.
 
hk33ka1 said:
The Lee pistol FCD CAN size the boolit and case mouth, sometimes in a bad way for those using oversized cast.

The rifle FCD does not have the carbide sizer ring at its base, and does NOT do this.


Iron Sighted I have shot lots of smooth Sierra bullets through my M14 with and without FCD, no problem.
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Thanks for that, adds some peace of mind.
 
With some calibers for which I do not use match grade brass, I use the FCD. I have done quite a lot of load development using it as a variable. My velocities were more uniform and groups were tighter when applying a LIGHT crimp.
These gains were marginal but they were there every time. These results coupled with the fact that my bullets will be less prone to moving in the case under recoil etc. is a good enough reason for me to continue using them.
 
What constitutes a light crimp? I adjusted mine until the collet just closed completely, is this a heavy crimp? I can just see a mark on the brass for the crimp.
 
Yes, that would be considered heavy and can crush the jacket of the bullet. With mine, I set the ram at full height, let the die contact the shellholder and then go about half a turn more.
I think with my 223 1/2 was too much and I went 1/3.
You can pull the bullet after you crimp and see if the jacket has been distorted.
 
The pistol FCD says half turn for a light crimp and a full turn for a heavy crimp. It's the same as said above, after it touches the shell holder you can adjust it to the crimp you want.

I use a heavier crimp for semi rifles, .38 and .357 and a taper crimp for 9mm cast or jacketed. IMO it is a great tool and is much easier then fussing with your seating die to get the depth and crimp you want. Even my .303 Enfield rounds get a heavy crimp and shoot great.

Cactus
 
f55 said:
The lee bullet seating die applies a crimp, how is the FCD any different?
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I'm not sure if the bullet seating die supplied with the 4 die pistol set actually applies a crimp. I think not, as I've managed to diagnose a brain fart by measuring when I didn't remember if I crimped or not and it was no where close to .473 for .45 acp. I don't even think it removes the bell. I could be wrong, but it seems to just push the bullet into the casing to the depth according to your adjustment.

The FCD has an adjustment for crimp. I set mine at around .471 and it doesn't seem to swag my cast boolit that was Lee sized at .452 (I've had to pull a few rounds). If you think it's squishing your lead, just turn the knob on top of the die counter clock-wise a bit.
 
Skyhawk said:
I'm not sure if the bullet seating die supplied with the 4 die pistol set actually applies a crimp. I think not, as I've managed to diagnose a brain fart by measuring when I didn't remember if I crimped or not and it was no where close to .473 for .45 acp. I don't even think it removes the bell. I could be wrong, but it seems to just push the bullet into the casing to the depth according to your adjustment.

The FCD has an adjustment for crimp. I set mine at around .471 and it doesn't seem to swag my cast boolit that was Lee sized at .452 (I've had to pull a few rounds). If you think it's squishing your lead, just turn the knob on top of the die counter clock-wise a bit.
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I have the 308 3 set die, the bullet seating die also crimps, but also have a FCD, is it needed if the seating die crimps or is the FCD better?
 
f55 said:
I have the 308 3 set die, the bullet seating die also crimps, but also have a FCD, is it needed if the seating die crimps or is the FCD better?
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That's an entirely different beast, and the FCD in your case might indeed be redundant. Lee however maintains that using their rifle FCD will hug your bullet more firmly :confused:

Hopefully someone here can answer your question, because I frankly have no experience with 308 and the FCD.

In the case of the 4 pistol die set, I can say that this isn't "snake oil" they're selling. The advantages of separating bullet seating and crimping have been discussed and tested to death on these forums.
 
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