Lee FCD and undersized bullets

[Al_Bundy]

Been speaking to Lee cs and they told me to look up "obturation" and that the undersized bullets my LFC die is forming will expand to the bores size when shot. Basically my die is sizing down the cartridge to spec and that includes my powder coated .452 down to .450. He also mentioned to pull apart a factory bullet and check the dimensions. As i did i saw the same .450" diameter on the Blazer's projectile. Have we been shooting undersized bullets this whole time with factory ammo? Was ordering a separate taper crimp and gonna trash the LFC but CS said to try them undersized as is and look for leading, if still not happy he'll look for a die that sizes closer to what im looking for.

[rsrocket1]

Have you shot your PC bullets?
You might be surprised to find that you don't have any leading even if you groove diameter is 1-2 mils wider than your bullets.
First of all, are you measuring the swaged bullet below the rim mark and if so, is there any portion where it was not swaged and still sitting above the case rim? If it is at or bigger than the groove diameter, you'll still be sealing off the gas cutting.

Even if you are getting a bit of gas cutting, you are likely cutting the powder coat before you get down to the lead. For the short time the bullet is in the barrel, the cutting may not be occurring long enough to get to the lead. I've seen this in some of my barrels:



This is probably from gas cutting of the PC. It wipes away with a dry wadded up paper towel so its obviously not lead.



Load up 50-100 and go out and shoot 'em. Check the barrel for leading after a few mags. The worst that could happen is you'll spend 30 seconds to a minutes with a Chore Boy wrapped mop to scrape out the lead.



The best that could happen is that you'll have cartridges that will shoot in any gun without hanging up and an easy clean up.

[reddog81]

For 45 ACP (I assume that's what we're talking about here...) i use the Lee dies for seating and "crimping". With the seating die adjusted most of the way down it actually removes most of the flare created from the expander. I use the body of the Lee FCD die to remove the final bit of flare from the case. I do not use the top portion of the die. I believe the top portion of the die is the part that is supposed to provide the taper crimp. I pulled a few bullets recently and they still measured .452. All my rounds work in my various 1911's

[Al_Bundy]

I pulled a few bullets recently and they still measured .452. All my rounds work in my various 1911's

Just what i needed, gonna send my fcd back since you're getting 452 still after running through the die there is no reason i should be getting deformed bullets. actually going to test the fcd for my 44 and 9mm as well so i can send any others that are swaging the bullet.

[Al_Bundy]

Have you shot your PC bullets?
You might be surprised to find that you don't have any leading even if you groove diameter is 1-2 mils wider than your bullets.
First of all, are you measuring the swaged bullet below the rim mark and if so, is there any portion where it was not swaged and still sitting above the case rim? If it is at or bigger than the groove diameter, you'll still be sealing off the gas cutting.

Even if you are getting a bit of gas cutting, you are likely cutting the powder coat before you get down to the lead. For the short time the bullet is in the barrel, the cutting may not be occurring long enough to get to the lead. I've seen this in some of my barrels:



This is probably from gas cutting of the PC. It wipes away with a dry wadded up paper towel so its obviously not lead.



Load up 50-100 and go out and shoot 'em. Check the barrel for leading after a few mags. The worst that could happen is you'll spend 30 seconds to a minutes with a Chore Boy wrapped mop to scrape out the lead.



The best that could happen is that you'll have cartridges that will shoot in any gun without hanging up and an easy clean up.

how much of that contaminate in your barrel would you say is affecting your accuracy? Would i see more of that if my bullets were at 452 compared to a smaller 450? You're right about having cartridges that will shoot in any gun if they're all compressed below the standard 452 barrel but it just rubs me the wrong way when i spend money on a 452 mold, 452 sizer and at the end of it all i have this die sizing my bullet to 450....

[fredj338]

Undersized bullets won't shoot well, regardless of the composition. Why many of us shun the LFCD. You aren't likely to get much obturation unless your pressures are up there, so I wouldn't want to count on that to "fix" the smaller bullet problem.

[runfiverun]

I would mail that fcd back to lee with a note explaining how they could put it to use.
there is an olde U-Tube saying... your doing it wrong.

[waco]

I have Lee FCD in 357 and 44. I chucked them up in a lathe and removed the carbide size ring. Problem solved.

[adam_mac84]

In 9mm, i stopped getting leading when I got rid of FCD. I use taper/seat in 1 step, and have 400 rounds without leading last weekend

[bbogue1]

In 9mm, i stopped getting leading when I got rid of FCD. I use taper/seat in 1 step, and have 400 rounds without leading last weekend

Adam_mac84 what does your 9mm barrel slug at and what is the diameter of your bullets you shot last weekend? I am having the same leading problem, however, I am looking to powder coating my remaining .356 bullets to make them bigger.

My 9mm slugs at .356 so I cast and size at .358 then powdercoat. If I don't need to powdercoat that would be nice.

[relic]

Is that all the chore boy you use??

[tazman]

I guess I'm just lucky.
I have Lee FCD dies for 5 different pistol cartridges and none of them swage my boolits down unless the brass case is extraordinarily thick. In most instances, it doesn't touch the sides of the case at all. It only crimps the case mouth appropriately.
I really like not having to worry about my cartridges chambering in any of my handguns. I also get great accuracy and no leading.
I guess I'm just lucky in this.(five 38/357 revolvers, seven 9mm handguns, one 40S&W, and two 45ACP 1911 pistols)

[NikA]

My .44 guns prefer a cast bullet in the .431-.432" range, and I had to adjust my Lee FCD accordingly. I used diamond paste on a expanding Acro Lap to remove the couple thousandths I needed off. While I was at it, I lapped the sizing die a couple thou larger to work the brass less also. Otherwise, I've had no complaints about the Lee FCDs.

[Larry Gibson]

Neither my 9mm or 45 ACP FCD cause any problems with leading......guess I'm lucky too.

[runfiverun]

how'd we ever get along without them...

[adam_mac84]

With FCD they were pulling at .352/3. I was sizing .356. Over a looong period of testing. I kept sizing my boolit up trying to maintain size after pulling (using fcd to get plunk)

Long story short. Ended at .3575 boolit size. With taper it will maintain .356-.3565 after pull.

Lots of guys say they get away with undersized PC boolits. I apparently cannot.


Slug .3555.


Sent from my iPhone using Tapatalk

[Grmps]

What works well for me is.
I seat and crimp with 1 die just to the point where the boolit won't move in the case when the cartridge is pushed against my bench
Then I run it through the lee fcd to where it just kisses the cartridge/bullet.
this allows passing the plunk test without downsizing the boolit

[Eddie17]

I’m in with using the FCD!
Works for me in most all my reloades!
Adjust to what you need an works great.
My 2 cents.
Eddie17

[DougGuy]

I have "heard" more than once that the LFCD carbide rings can be fairly inconsistent. Some will downsize a .452" and others won't. Go figure. I do have a Sunnen hone and some diamond stones for it, I would be willing to hone the carbide ring to fix the issues.. It would be nice to have one that doesn't downsize a .452" so that I can use the Starrett dial bore gauge to mic it and see what the ID needs to be.

[Jniedbalski]

My 40 S&W and 9 fcd works fine