Lee Factory Crimp/Cast Bullet Modification

[flat top]

I load oversized cast bullets in my handguns...normally .431, .432

I also like the Lee Factory Crimper, and use it with a heavy crimp for my 44 Mags.

The Lee Factory Crimper has a a carbide collet insert in the base of the die, and that insert is used to size the loaded round before the crimp takes place....according to Lee, to allow the loaded cartridge to fit standard sized chambers, and to reduce crushing of the cartridge during the crimping process. The only problem with this collet is the fact that it WILL size down an oversized cast bullet. A buddy of mine reported that his Lee Factory Crimp Die was sizing down the case/oversized cast bullets as much as .002 therefore negating the oversize condition of the bullets and affecting accuracy.

I ground the collet in my die, to allow a .432 seated bullet to "slip fit" the collet. The die collet no longer "sizes" the rounds that I crimp, and it works properly and gives a nice uniform and square crimp, and will not crush the cases during the crimping process regardless of the size of bullets that I am working with.

Grinding the carbide collet by hand is very hard, to impossible, but any good machine shop that has a cylindrical grinder could accomplish this task.

Because of the amount of folks that shoot cast bullets on this forum, I though (that if this has not been mentioned before), that it should be posted for your info.........

 

[Gun 4 Fun]

That's interesting info. I don't use them myself, but I know a lot of guys here do. I bet they'll appreciate the info too.

 

[Skip Sackett]

Good information, flat.

I just have one question though. Your modified die, what difference does it have over the crimping portion of a regular die now that you modified it?

This is how I do what you explain but without modifying anything. I use two regular Lee seating/crimping dies in my turret and progressive presses. I am blessed with a 5 hole progressive so I don't lose any of it's benefits either.

I screw the stem all the way in on the bullet seating portion or rather to the point that the case comes back to straight then in the next hole I have the same die with the stem almost removed but turned down far enough to give me the crimp I desire.

The over size bullet is not touched and I get a great crimp on the bullet.

If I was doing this in a single stage press it would be cumbersome, but I just pull the handle and the machine does the rest!

 

[flat top]

Thanks G4F!!!

SC; If I understand your question...The crimping portion of the die is not affected by the modification...only the dimensions of collet (actually, it is a carbide insert) in the base of the die. I studied this as best I could, and I think that the base of the Lee Factory Crimping die needs to center/support the head of the case as the bullet is crimped, to assure a "square" and uniform crimp. When I set the die up in my press, the shell holder is touching the bottom of the die (and thus the case is centered and supported) as the crimp is applied. The "stem" portion of the die not only sets the crimp, but also centers the bullet, so the cartridge is being centered for the crimp at both ends of the cartridge. After I ground the collet to allow a seated .432 cast bullet a slip fit thru....the collet is still snug enough to center/support the case head (if I remember correctly, the tolerance on that was .0002 over the nominal diameter of the case head). I also ran a variety of different sized bullets from .429 through .432, and the crimps were square and uniform regardless of the diameter of the bullets, so, the smaller bullets were not affected by the modification, the crimps were square and uniform, and there was no case crushing.............In the case of my (and my buddies) Lee Factory Crimp dies, the minute the cartridge entered the die there was resistance...it kind of "chunk and clunk" (the sizing effect of the collet on the oversized seated bullet) as it moved upward towards the crimp area of the die. Now, the cartridge enters the die smoothly, the crimp is applied and the cartridge is removed with no resistance from the collet. I hope I have answered your question?..................I dont have a turret or progressive press...really, just never had a need for one. Most of my reloading is purpose driven, and all my rifles, except for my 444 levergun, are loaded with custom made benchrest dies (hand dies). I load the pistol rounds with an old single stage press.

 

[Steve C]

How do you get the oversized cases to chamber in your revolvers unless you have particularily generous chambering?

I've found that while many times rounds that are slightly oversized will fit in Smiths but they will not chamber in a Colt with their tighter tollerances. The Lee FC die makes sure the OD of the case is no greater than maximum SAAMI standard and rounds shouldn't be sized by the the FC die at all unless they're bulged in the loading process.

 

[fredj338]

How do you get the oversized cases to chamber in your revolvers unless you have particularily generous chambering?

I've found that while many times rounds that are slightly oversized will fit in Smiths but they will not chamber in a Colt with their tighter tollerances. The Lee FC die makes sure the OD of the case is no greater than maximum SAAMI standard and rounds shouldn't be sized by the the FC die at all unless they're bulged in the loading process.

I have never had issues w/ magnum rounds fitting in any revolver. I find the LFCD counter productive to accuracy w/ lead bullets. One could certainly go the route as FT did, but a properly sized case & a good roll crimp have sufficed for my revolver rounds for years. Same for pistols, a good taper crimp is all that is needed. I think Lee came up w// this little gimick to acount for poor tolerances of their sizing dies. AS always, JMO.

 

[flat top]

Steve and Fred; I have never had a problem with a cartridge fitting in any of my chambers (like Fred)....and , Fred may be correct about Lee's Factory Crimping Die being indigenous to the Lee line (all my other dies are RCBS). There have been a few times when I have shot cartridges that have not been put through the Lee crimping die, and they fall right into the chambers with the oversized bullets that I use. I have found that the Lee Factory Crimp Die does improve accuracy and ballistic uniformity (chrono) in my pistols and my 444 levergun (although the 444 crimp die is of a different design, and does not have these issues). In spite of the problem I had with this die, I believe that the results of using this type of crimp have proven to work well, and if anyone was experiencing this issue, I was hoping that my post would solve the problem for them.

 

[Skip Sackett]

The crimping portion of the die is not affected by the modification

Exactly, and if I understand the Lee design well enough, and I use them almost exclusively, the 44Mag die has a roll crimp in the seating die that comes with the set. So again, since you modified the collet, virtually taking it out of the procedure, how does that die differ from a regular seating die?

The whole purpose of the LFCD is not to improve the crimp but to size the case after loading to factory ammo spec's. At least, that's how I understand it's purpose. I only use it in one caliber, a LFCD, 45ACP where I have had some problems with brass that was thick, Fiocchi, and bullets that were running in the .453" neighborhood. Those will not chamber in my M625JM, period.

In that firearm, the resizing of the bullet is not an issue as when I can get them to chamber with the LFCD, they are still able to obturate just fine.

There is no one thing fixes all when it comes to firearms, they are all individuals.

 

[M29since14]

I don't have or use factory-crimp dies, but have considered experimenting with one. Thanks. That's good information, and something that could be easily overlooked. I too generally use oversize cast bullets in my .44 Magnums - usually .431".

 

[flat top]

SC; I have no clue as to what Lee Die's do or how they are made...I only have RCBS Dies. The RCBS dies apply a roll crimp, the Lee Factory Crimp Die applies a taper crimp (truthfully I dont know if that would be the correct term for that crimp...but, I believe thats what Lee calls it. It actually looks more like a swage of the case mouth more than anything else), and that is the crimp I prefer, and that crimp that has given me the best accuracy. Regardless of what its called the Lee Crimp Die applys something other than a roll crimp, and thats the one that works for me. I only shoot 44 Special and 44 Magnum handguns, and that is all I reload for now....so, how the Lee Factory Crimp Die would be set up for other applications is up to the user to decide. I shot 45ACPs in competition for years, and even with that gun I would always put a very slight crimp on the case mouth, but, not enough to upset headspace of course. As far as the universal to all firearms issue that you mention....This Lee crimp has shown an improvement in accuracy in all my Smiths and Rugers, but I would or could not say that it would do so in every handgun out there.....the "odds" are against me in that case!!! Anyway, it was just something that we came across and wanted to share...Take it or leave it, its just another experience shared with the forum.

 

[flat top]

M29since14; You know, I have a 444 Marlin that uses a very different Lee die to apply a crimp (its a collet die, that does not resize the case...and, has no effect on the diameter of the seated bullet). That die works like a champ, and in the 444 it really shows a great improvement in accuracy, and ballistic uniformity (as judged by the chronograph).....Now, you have me thinking. I wonder if the 444 die could be shortened for use with the 44 Magnum?!?! This would be the ideal set up if it would work! This may be something worth looking at. It would be much easier to shorten the 444 die, than it would be to open up the carbide insert in the base of the Lee Factory Crimp Die.

 

[Skip Sackett]

flat,
I still think you are missing my point.

I crimp everything. Some I use a LFCD some I use the seating/crimp die that comes standard with the pistol set.

I agree that the right crimp is essential for accurate rounds. The modification that you are sharing about is one that I see a place for. Some handguns would really benefit from the bullet being left alone. The point I was trying to make was that some bullets that get resized, still function just fine in that individual firearm. Like my M625JM.

Now if it had big throats or bore things would be different for sure! I would look at something like you have described.

The 444 crimp die is a rifle collet die. It doesn't work like the handgun dies at all.

The crimps that are applied by the LFCD are specific to caliber. A cartridge that is a traditional revolver round gets a Factory Roll Crimp, one that is traditionally a semi-auto cartridge is given a Factory Taper Crimp by the LFCD for that caliber.

 

[flat top]

Now I understand...I must be delusional this morning! You are correct, some revolvers, especially with light target loads dont even need a crimp to perform well, and some guns just dont like oversized bullets. Most of my loads are midrange to top end, where the crimp really makes the difference, not only in eliminating "jump", but aiding in accuracy and ballistic uniformity...also, all my guns shoot oversized bullets much more accurately, but I can see where the die as it comes from Lee can work in situations other that my own. I will not dispute that.....The 444 is nothing more than a long 44 Mag (in essence), and I dont see why a shortened version of the 444 collet die would not work with the 44 Mag "if" the interior demensions of the 444 die would accept the 44 mag case and perform the same function. I actually like the 444 collet die better than the Lee Factory Crimp die that I am now using for the 44 Mag. It would be worth researching to see how or if it would work out. Right now I am in the middle of another project, so that will have to wait............I am not all that familiar with Lee products. The Lee Factory Crimp die that I have does not put a roll crimp on my 44 mag cases, matter of fact, the crimp looks identical to the crimp that is applied to the 444 cases by the collet die.................Just to clarify, does the regular Lee seating die that comes with a "set", roll or taper crimp? My RCBS seating dies roll crimp, and that crimp is not at all like the crimp that my Lee Factory Crimp Die applies to my 44 Mag cases. I have had all these dies for many years...I wonder if something has changed?

 

[Skip Sackett]

Here are some of the crimps I put on my bullets.
The first one has no real crimp. It is a 38spl with 158gr LSWC and 3.5gr Bullseye. No crimp needed at all. These will shoot 1" groups @ 25 yards all day long.

Same type of round, target, only with roll crimp via normal seating die.

My 44Mag rounds with an H&G #503, Elmer Keith 250gr bullet. This crimp is what comes standard with a Lee 44Mag seating die.

Do these crimps look anything like the ones you get from your dies?
Can you take pictures of your rounds and post them?

 

[flat top]

SC; I would have to say that both the 44 Mag and the 444 Marlin, Lee Crimp dies that I have produce a crimp that is more similar to the last photo. I cant post on this forum, but, if you email me I will "try" to take a photo: [email protected]

 

[flat top]

SC! I got some photos of my crimps, and they dont look anything like yours!!!! I thought your last photo was close, but it seems that I was wrong! My cartridges after crimping look like they have a swaged ring or "band" residing in the crimp groove, and both the 444 and the 44 Mag die crimps are exactly alike!

 

[Bearcat74]

How do you guys know that the Lee FCD is crushing the bullets? I can load a bullet into a case and insert it into the FCD with no resistence until it hits the crimper?


Thanks

 

[flat top]

Bearcat74; It all depends on the diameter of the bullet. If I load a .429 jacketed (or cast) bullet I would not have the problem, but, some of my handguns need .431 and .432 cast bullets, and thats when the problem starts. The tolerance of the Lee die sizing insert is so critical to the standard dimensions of the the 44 Mag cartridge (in my case), that any bullet over .430 actually gets sized down, which ruins accuracy. You can tell this is happening because you will meet resistance as the cartridge enters the insert in the bottom of the die...and, the larger the bullet diameter the more resistance you will encounter. A buddy of mine told me about it...he had mic'd some cartridges that he had just loaded, and he said after a trip through the Lee Factory Crimp Die, the measurement he took, where the bullet was seated, was reduced by .002 ! So, the bullets he loaded (.432's) were worthless for accuracy in his handgun. I am not saying that the Lee Factory crimper is bad, I am just saying that if you are loading "cast bullets" larger than the "standard", that the Lee die will size them down...then offered a remedy for that issue. Hope this helps.

 

[Bearcat74]

Flat top, thanks for the explanation. I am shooting .430" so I think I will be ok. I was worried that it would size down .430's.


Thanks again!

 

[flat top]

Bear; If you dont feel any resistance when the loaded round first enters the die, you are good to go!!!!