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Lee FCD (pistol, not rifle) the Virtue and the Vice

Thanks to blazerbowe for sharing his question on his thread:

"Plunk-Test" .45acp Question... - THR

The post-sizing feature of the Lee Pistol FCD (Factory Crimp Die) would "cure" blazerbowe's problem (the virtue). This, according to Lee Precision, is the principal reason for the existence of the pistol FCD.

But it would do nothing to identify or cure the cause (the vice)

In fact, by squishing the bullet inside the case, might create another problem (inadequate grip of the case on the bullet or loose bullet tension). This is particularly problematic with lead bullets, less so with jacketed.

I took this opportunity to post because these simple facts often get lost in the heated rhetoric that sometimes invades threads about the Lee FCD.

Thanks for reading.
 

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This is just an invitation for Lee haters to start their rant.
The ONLY problem I have had with Lee FCDs is when my bullets are 0.003" or larger than the minimum nominal bullet diameter and the bullet is swaged down and loses accuracy and can lead (the use of Lee Liquid Alox eliminates a lot of leading of even slightly too small bullets).
No problem with standard jacketed or standard lead bullets.
It is not the same dimension as a sizing die and brings the case to just under the minimum chamber dimension for the cartridge. Check the SAAMI site for cartridge and chamber drawings and see the "slop" between the two.
If you have an occasional round that doesn't chamber, you would be well serve with the Lee FCD. It also does about the best crimp of ANY die on the market.
If you have a lot of round that don't chamber, you need to check your reloading set-up and fix the problem.
 

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I think many people lose sight of what crimps are all about. No, I'm not a Lee hater ... just presenting the facts.

The purpose of a crimp is threefold ... first, it removes the bell in the case mouth that got there with the expander die. Second, it allows the cartridge to feed and chamber properly, and third, it adds about 10% to neck tension.

When your equipment is set up properly, the case will be sized down just a few thousandths under it's normal diameter by the sizing die. After the expander die is used to flair the case mouth, a bullet can be seated without damaging the case. When a bullet is seated but not crimped, neck tension from the slightly undersized case should provide about 90% of case neck tension needed to hold the bullet in place. The last 10% comes from the crimp die.

Several years ago when Lee FCDs started getting popular, I bought a couple Lee 4-die sets (with FCDs) ... one for 38/357 and the other one for 45 ACP. I ran many tests with different brands of dies just to see what all the hype was about. To keep everything fair, I used the same brand of once fired 38 Special and 45 ACP brass, weighed each powder charge precisely, and used the same bullets in like cartridges. Bullets were seated and crimped in separate operations. After loading test batches, I took them to the range and tested them over a chronograph. As the old saying goes "the proof is in the pudding" so each 10 round batch was tested for average velocity and more importantly .... maximum velocity spread (slowest versus fastest in the 10 round string). The results with Hornady, RCBS, Lyman, Lee, and Dillon were nearly identical with jacketed bullets .... all had about the same max velocity spreads and the same average velocity. This tells me when the individual brand crimp dies were adjusted properly, there wasn't any significant difference from die brand to brand ..... ADJUSTED PROPERLY being the key.

The real difference showed up with 38 Specials, loaded with Speer 158 gr LRNs and 45 ACPs, loaded with Speer 230gr LRNs. All but Lee brands produced very uniform velocities with tighter max spreads than with jacketed bullets. The lead bullet loads from the Lee dies failed miserably. Velocity spreads were about 100 fps and average velocity was at least 50 fps lower than with the other brands of dies. Lower velocities were a result of the bullets being squished smaller ... wild velocity spreads were a result of poor and/or inconsistent neck tension.

Back to the bench where I loaded up a couple more batches. This time I loaded a 10 round batch of each of the cartridges using the Lee die set and the FCDs. I loaded a second batch with the carbide ring removed from the FCDs. Guess what? The loads with the normal FCDs produced the same results ... wild max velocity spreads. The load without the carbide ring in the FCDs produced about the same results as the other brands ... very uniform velocities. Granted, my test procedures may not have been as tight as a SAAMI laboratory, but the results told me Lee FCDs were not what they were bragged up to be when used with lead bullets. Turns out ... FCDs squished the lead bullet diameter smaller, making the bullets lose their seal in the bore. If you don't believe this, try pulling some bullets loaded with a FCD and measure the ODs. You will find a .358" lead bullet comes out about .356" and a .452" comes out about .450".

When case neck tension coupled with crimp is correct, it should take about 35 lbs minimum and 50 lbs maximum pressure to push the bullet deeper into the case. When neck tension is less than 35 lbs, the bullet will start moving before the powder has a chance to fully ignite, resulting in excessive velocity spreads. If neck tension is over 50 lbs, it has virtually no affect on powder ignition. A simple test is to hold the cartridge firmly and push the nose of the cartridge against a solid work bench. If the bullet moves at all, something is wrong with neck tension or crimp.

I got so involved with this series of tests that I made a "neck tension tester" from a Lee 45 Colt bullet seater die. I installed a Ruger SA hammer spring inside the cup of the die so when it is adjusted properly for a given cartridge (works with any cartridge from 9mm to 45 Colt), when you have the case inserted in its shell holder and pull the handle fully down, spring tension will apply 35 lb of force on the nose of the bullet. When you do a "before and after" caliper measurement, any shorter "after" COL indicates inadequate neck tension. Lee FCDs with lead bullets would allow bullets to seat deeper with this device, as would jacketed bullets with any brand of crimp die if too much crimp was applied. Here's the device I made showing the die disassembled:



On to "proper crimps" .... If a sized empty case will chamber in a gun or a case gauge but won't fit after it has been loaded, there is but one reason .... too much crimp was applied. If the crimp die is screwed in too far, when you pull the handle something has to give and that is the case. In extreme situations, the case can actually wrinkle but most of the time, excessive crimp just makes the case expand. This always results in poor neck case tension, leaving just the crimp to hold the bullet in position. When too much crimp is applied then a FCD is used to "iron out" the case, this very poor procedure will result in wild velocity spreads.

Most people tend to crimp too tight ... thinking it will hold the bullet tighter. Fact is, usually it has the opposite effect and actually loosens overall neck tension. Remember, the crimp should only account for about 10% of the overall neck tension so if you do a "hard crimp" you may increase crimp tension to 20% but reduce case body neck tension by 50% ... net result is 30% less neck tension and possibly an over expanded case. Lead bullets with a crimp groove can be roll crimped tighter to prevent "bullet jump" but only enough where the case does not expand.

Bottom line ... With exception of using lead bullets in Lee FCDs, all brands of dies produce excellent crimps when adjusted properly. Lee FCDs do a decent job with jacketed bullets but do a poor job with lead bullets, even when adjusted properly. Removing the carbide ring will make a FCD work much like a conventional crimp die with much better results.
 

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Discussion Starter #4
Iowegan I tip my hat to you.

Most people tend to crimp too tight ... thinking it will hold the bullet tighter. Fact is, usually it has the opposite effect and actually loosens overall neck tension. Remember, the crimp should only account for about 10% of the overall neck tension so if you do a "hard crimp" you may increase crimp tension to 20% but reduce case body neck tension by 50% ... net result is 30% less neck tension and possibly an over expanded case. Lead bullets with a crimp groove can be roll crimped tighter to prevent "bullet jump" but only enough where the case does not expand.
I think a description that might be illuminating might be to refer to the children's toy known as "Chinese handcuffs". A woven, stiff tube that fattens when the ends are moved toward one another (as when you insert a finger into each of the ends) and then narrows (gripping your fingers) when you pull the ends apart.

Did I understand correctly what you described? That the brass "fattens" when the crimp shoulder presses on the case mouth and tends to loosen the case's grip on the bullet, even while the case mouth crimps in?

On to "proper crimps" .... If a sized empty case will chamber in a gun or a case gauge but won't fit after it has been loaded, there is but one reason .... too much crimp was applied.
I believe I know another reason. My Dan Wesson .357 Magnum has pretty tight chambers. Most of the lead bullets I have used have given no problems, but I got one batch that were just a tad oversized. They bulged one lot of nickle-plated cases just enough to not chamber. Unplated brass cases fit OK. There was just enough extra diameter to the slugs and enough extra thickness to the cases to make a difference.

Post-sizing the cartridges solved the problem, but I am pretty sure that if I had clocked them as you did, the velocities would have been disappointingly spread. But this was decades before I had access to a chronograph.

Thank you for taking the time and effort to look into this and write your post. With your permission I will be quoting you extensively (with attribution, of course). This is one of the best reasoned and well-supported (by evidence) arguments for and against the Lee (straight-walled case) FCD that I have ever seen.

Kudos to you, sir.

Lost Sheep
 

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Lost Sheep, "Chinese Handcuffs" (or finger cuffs) are a good analogy and yes, I think you understood the concept correctly. Here's what happens inside all crimp dies. As pressure is exerted on the press handle, the angle at the top of the die pushes the case mouth in until it is tight against the bullet. At that point (optimum crimp), if the die is pushed down further, the case can't crimp the bullet much tighter so downward pressure will begin to puff up the case ... just like pushing the Chinese finger cuffs together. Once the case walls have expanded, neck tension on the bullet gets lighter.

Things aren't always what they seem concerning cases. If you use your caliper and measure the wall thickness of nickel plated brass cases, you will find they are about 20% thinner than standard brass case walls. This makes the cases much weaker so when you over crimp just a little, they will puff up much more than thicker brass cases. You would expect nickel plated cases to chamber easier but often just the opposite happens. As you mentioned, fat bullets will cause cases to expand but they would have to be at least .360" (in a 357 mag) before chambering would be an issue with nickel plated brass. My bet ... you had the crimp die adjusted too tight. In other words, the fat bullets made your crimp die "bottom out" on the case mouth too soon so when you pull the handle farther down, it resulted in an "over crimp" condition.
 

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Discussion Starter #6
Lost Sheep, "Chinese Handcuffs" (or finger cuffs) are a good analogy and yes, I think you understood the concept correctly. Here's what happens inside all crimp dies. As pressure is exerted on the press handle, the angle at the top of the die pushes the case mouth in until it is tight against the bullet. At that point (optimum crimp), if the die is pushed down further, the case can't crimp the bullet much tighter so downward pressure will begin to puff up the case ... just like pushing the Chinese finger cuffs together. Once the case walls have expanded, neck tension on the bullet gets lighter.

Things aren't always what they seem concerning cases. If you use your caliper and measure the wall thickness of nickel plated brass cases, you will find they are about 20% thinner than standard brass case walls. This makes the cases much weaker so when you over crimp just a little, they will puff up much more than thicker brass cases. You would expect nickel plated cases to chamber easier but often just the opposite happens. As you mentioned, fat bullets will cause cases to expand but they would have to be at least .360" (in a 357 mag) before chambering would be an issue with nickel plated brass. My bet ... you had the crimp die adjusted too tight. In other words, the fat bullets made your crimp die "bottom out" on the case mouth too soon so when you pull the handle farther down, it resulted in an "over crimp" condition.
I wish I had pictures. The cases were bulged from the case mouth all the way down to the base of the bullet and there was (as is my habit) minimal crimp at the case mouth. The too-large diameter was definitely due to the case being bulged by the bullet, not being squished by a zealous crimp.

Your explanation of how a zealous crimp can make a case go to a larger diameter does make perfect sense, though.

Thanks again.

Lost Sheep
 

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As a novice reloader who was a believer in Lee's FCD whats the best solution? Crimp with your bullet seating die or remove the carbide ring? How can the carbide ring be removed and not scratch the die or mar the surface. I have used the FCD for 3 yrs and thought it was doing it's job. I load Missouri bullets almost exclusively and they always chamber well and my groups seem to be as good as my 60yr old eyes can see. That's one of the reasons I read this site. There is always something to learn.
 

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Discussion Starter #8 (Edited)
As a novice reloader who was a believer in Lee's FCD whats the best solution? Crimp with your bullet seating die or remove the carbide ring? How can the carbide ring be removed and not scratch the die or mar the surface. I have used the FCD for 3 yrs and thought it was doing it's job. I load Missouri bullets almost exclusively and they always chamber well and my groups seem to be as good as my 60yr old eyes can see. That's one of the reasons I read this site. There is always something to learn.
Well-considered questions. Not to worry.

"was a believer"? No need to change your belief. I believe in wrenches - where appropriate. If you don't mis-use either tool, belief does not have to be abandoned. Just don't mis-use it. It is not always needed. On the occasions when not needed, it does no harm.

Remember, the Lee FCD performs two functions.

1) Crimping (or at least removing the case-mouth bell/flare that allowed the bullet to be started into the case).

2) Sizing the cartridge after bullet seating (useful if the case has been bulged to the point where it will not chamber reliably).

Personally, I feel the second function should be a user-selectable option. But a removable part that the owner could screw into the die when desired and leave out when not desired would be more expensive than just buying an extra die (either an FCD from which the post-sizing ring had been removed or a Seat-Crimp die from which the seating stem had been removed.)

Theoretically, the post-sizing ring is not needed (if all the prior loading steps have been done properly with properly adjusted dies and properly sized bullets). It only works the cartridge if it is oversized for a SAAMI-specification chamber.

I load Missouri bullets almost exclusively and they always chamber well
If they chamber well without having used the FCD to crimp, then you don't really need the FCD unless you prefer to crimp in a separate step or if you like the "floating" crimp ring design. Removing the post-sizing ring is an option I would consider in this case. But if you closely examine your crimp step, I suspect you will find the post-sizing ring does not actually even touch the case, or if it does, touches it only lightly and does no work on it.

You might test my suspicion by dropping a loaded, (regularly)crimped cartridge into the FCD by hand. Or you could paint a cartridge with an erasable magic marker and see if the coloring gets rubbed off. Or you could just observe closely the amount of pressure it takes to run your cartridges in and out of the FCD. If (aside from the initial "bump" as the case mouth enters the die) it goes the rest of the way in and out with little pressure, and the same amount of pressure, your FCD post-sizing is doing no harm. Fourth way to tell is to measure a cartridge diameter before and after the FCD. If the same, the post-sizing has done nothing, good or bad. (Measure the diameter in several directions, just to check for an out-of-round condition, which would confuse things considerably.)

How can the carbide ring be removed and not scratch the die or mar the surface?
I have never done it, but I have been told to mount the die body (remove the inner parts) in your press or in a vice, take a hammer or mallet and a flat-nosed punch (or other device like that), catch the punch on the carbide sizing ring and give it a whack. This is an irreversible procedure. It will probably be broken and even if it comes out in one piece you will be unlikely ever to get it back in and if you do, it may not be straight.

Even if the area where the ring was removed is scratched up, this part of the die will not touch your brass if the cartridge is centered in the shell holder.

For $30, Lee Precision will grind out the carbide post-sizing ring to any specification you request. I expect if you asked for an FCD without the ring there would be no charge. If enough people asked, they might even make it a catalog item.

Sorry to be so long-winded.

From your description, I suspect you are fine and doing everything correctly. If I were you, I would watch my loading process and when running my rounds up into the FCD, observe the force required on the operating arm as the body of the cartridge that grips the bullet enters the die (ignoring the initial entry of the first 1/16" case mouth), apply a very light crimp and then observe the force required on the operating arm as the cartridge is withdrawn. Then repeat the process, applying my regular crimp. If the force over the length of the cartridge is the same on all four trips through the post-sizing ring, all is good.

Lost Sheep

p.s.
There is always something to learn.
Thanks for asking. Your questions prompted me to more thinking about this and Iowegan's mention of the bulge caused by over-crimping has educated me and further refined my answer to you. Hence the four passes I prescribed in my last paragraph. If, on the last pass, you find more force required, your crimp, not the bullet, bulged the case.

Lost Sheep
 

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Thanks for the reply Lost Sheep. A very good explanation to my question. I don't load "hot loads", most under 1000 fps. My goal is light to medium loads. I never use a really heavy crimp and have never noticed any issues. I have little or no leading and pretty good accuracy. Thanks to Iowegan for his insight and to you for answer to my question.
 

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I think many people lose sight of what crimps are all about. No, I'm not a Lee hater ... just presenting the facts.

The purpose of a crimp is threefold ... first, it removes the bell in the case mouth that got there with the expander die. Second, it allows the cartridge to feed and chamber properly, and third, it adds about 10% to neck tension.

When your equipment is set up properly, the case will be sized down just a few thousandths under it's normal diameter by the sizing die. After the expander die is used to flair the case mouth, a bullet can be seated without damaging the case. When a bullet is seated but not crimped, neck tension from the slightly undersized case should provide about 90% of case neck tension needed to hold the bullet in place. The last 10% comes from the crimp die.

Several years ago when Lee FCDs started getting popular, I bought a couple Lee 4-die sets (with FCDs) ... one for 38/357 and the other one for 45 ACP. I ran many tests with different brands of dies just to see what all the hype was about. To keep everything fair, I used the same brand of once fired 38 Special and 45 ACP brass, weighed each powder charge precisely, and used the same bullets in like cartridges. Bullets were seated and crimped in separate operations. After loading test batches, I took them to the range and tested them over a chronograph. As the old saying goes "the proof is in the pudding" so each 10 round batch was tested for average velocity and more importantly .... maximum velocity spread (slowest versus fastest in the 10 round string). The results with Hornady, RCBS, Lyman, Lee, and Dillon were nearly identical with jacketed bullets .... all had about the same max velocity spreads and the same average velocity. This tells me when the individual brand crimp dies were adjusted properly, there wasn't any significant difference from die brand to brand ..... ADJUSTED PROPERLY being the key.

The real difference showed up with 38 Specials, loaded with Speer 158 gr LRNs and 45 ACPs, loaded with Speer 230gr LRNs. All but Lee brands produced very uniform velocities with tighter max spreads than with jacketed bullets. The lead bullet loads from the Lee dies failed miserably. Velocity spreads were about 100 fps and average velocity was at least 50 fps lower than with the other brands of dies. Lower velocities were a result of the bullets being squished smaller ... wild velocity spreads were a result of poor and/or inconsistent neck tension.

Back to the bench where I loaded up a couple more batches. This time I loaded a 10 round batch of each of the cartridges using the Lee die set and the FCDs. I loaded a second batch with the carbide ring removed from the FCDs. Guess what? The loads with the normal FCDs produced the same results ... wild max velocity spreads. The load without the carbide ring in the FCDs produced about the same results as the other brands ... very uniform velocities. Granted, my test procedures may not have been as tight as a SAAMI laboratory, but the results told me Lee FCDs were not what they were bragged up to be when used with lead bullets. Turns out ... FCDs squished the lead bullet diameter smaller, making the bullets lose their seal in the bore. If you don't believe this, try pulling some bullets loaded with a FCD and measure the ODs. You will find a .358" lead bullet comes out about .356" and a .452" comes out about .450".

When case neck tension coupled with crimp is correct, it should take about 35 lbs minimum and 50 lbs maximum pressure to push the bullet deeper into the case. When neck tension is less than 35 lbs, the bullet will start moving before the powder has a chance to fully ignite, resulting in excessive velocity spreads. If neck tension is over 50 lbs, it has virtually no affect on powder ignition. A simple test is to hold the cartridge firmly and push the nose of the cartridge against a solid work bench. If the bullet moves at all, something is wrong with neck tension or crimp.

I got so involved with this series of tests that I made a "neck tension tester" from a Lee 45 Colt bullet seater die. I installed a Ruger SA hammer spring inside the cup of the die so when it is adjusted properly for a given cartridge (works with any cartridge from 9mm to 45 Colt), when you have the case inserted in its shell holder and pull the handle fully down, spring tension will apply 35 lb of force on the nose of the bullet. When you do a "before and after" caliper measurement, any shorter "after" COL indicates inadequate neck tension. Lee FCDs with lead bullets would allow bullets to seat deeper with this device, as would jacketed bullets with any brand of crimp die if too much crimp was applied. Here's the device I made showing the die disassembled:



On to "proper crimps" .... If a sized empty case will chamber in a gun or a case gauge but won't fit after it has been loaded, there is but one reason .... too much crimp was applied. If the crimp die is screwed in too far, when you pull the handle something has to give and that is the case. In extreme situations, the case can actually wrinkle but most of the time, excessive crimp just makes the case expand. This always results in poor neck case tension, leaving just the crimp to hold the bullet in position. When too much crimp is applied then a FCD is used to "iron out" the case, this very poor procedure will result in wild velocity spreads.

Most people tend to crimp too tight ... thinking it will hold the bullet tighter. Fact is, usually it has the opposite effect and actually loosens overall neck tension. Remember, the crimp should only account for about 10% of the overall neck tension so if you do a "hard crimp" you may increase crimp tension to 20% but reduce case body neck tension by 50% ... net result is 30% less neck tension and possibly an over expanded case. Lead bullets with a crimp groove can be roll crimped tighter to prevent "bullet jump" but only enough where the case does not expand.

Bottom line ... With exception of using lead bullets in Lee FCDs, all brands of dies produce excellent crimps when adjusted properly. Lee FCDs do a decent job with jacketed bullets but do a poor job with lead bullets, even when adjusted properly. Removing the carbide ring will make a FCD work much like a conventional crimp die with much better results.
Interesting stuff! Thanks (again), Iowegan!
 
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