Lee Factory Crimp die for Handgun Cartridges and Cast Bullets
Quote:
Originally Posted by
robertbank
Dan lead bullets are usually sized .001 or .002 over bore. For 9MM that would be either .356 or .357, Plated/FMJ are usually .355. When you load a cast bullet the case will show a slight bulge. This bulge is completely normal. I have at least 7 different 9MM pistols and they all feed my .357 bullets slightly bulged cases with ease.
When you see the bulge when you load 9MM and then apply a FCD to smooth out the case bulge it bullet gets swaged down. Depending upon the thickness of the brass I would end up with a cast bullet going from my preferred .357 to < .357. My experience has been the reduced bullet is closer to .355 which is not what you want if you want to ensure a solid seal to prevent gas cutting and the resulting leading in the barrel. It really galls to the physics observation that two things cannot occupy the same space at the same time. when you squeeze the case down you squeeze the lead bullet down in size.
You may not notice any difference in performance but you do set yourself up for leading issues if you 9MM pistol has a barrel with a .356 or .357 bore. I found I has a bit of leading but bullets that were not stable. Accuracy was about the same inside of five yards but at 20 yards accuracy for me deteriorated noticeably. I tossed my FCD for 9MM and 45acp that I had. I never had one for the 38spl/.357mag,
Fact: If you reduce the outside diameter of the case you reduce the bullet diameter by the same amount. Old man physics does not lie. All you have to do is measure a bullet before you lead it and pull one after you apply the FCD to eliminate the bulge.
One thing to remember as well all 9MM FCD's are not the same. Knowing Lee you could vary + or - .001. I had a Lee sizing die marked .357 that actually sized the bullets .356. I also had another die that read .356 and sized the bullets .356.
I know have my push through dies made by a guy out in Montana. His name escapes me. They are what they say they are.
Take Care
Bob
This isn’t necessarily true. And certainly not in 9MM.
This is one of those wives tales that has persisted in the loading community much like “don’t load your own SD ammo”.
I actually just did an experiment the other day to put this to rest.
BTW I was actually ready to accept the fact that the LFCD did in fact swage the bullet down.
I took 3 types of different cast bullets that were loaded and crimped to .380”. Mixed brass was used so I had everything from the most problematic thick walled cases to the standard run of the mill stuff.
I then took a Lee FCD with the crimp plug removed and slowly ran each case into the FCD.
WITHOUT FAIL the FCD never touched the portion of the case with the bullet in it. The FCD never even made contact with the case until the bottom 1/3 of the case.
This is most likely due to the coke bottle shape of the 9MM case.
All crimps were still .380”
There is no way the FCD is swaging down bullets. At least in 9MM.
I also ran this experiment with 2 different LFCD’s. I have 2 dies that were purchased at separate times for different machines. Same exact result.
I wanted to rule out the “I got one of the over sized ones” arguments.
I also pulled several bullets and verified they were still .356”.
At least in 9MM the bullet would have to be so over sized to come in contact with the ring of the FCD that you’d have many other problems to contend with. Swaging would be the least of your concerns.
Now, that being said, I ran the same experiment in 40SW and my results were mixed at best. I found the ring of the FCD was coming in contact with the case much sooner. Maybe the the bottom 1/2.
The pressure needed to push past the contact point was minimal so I question whether or not any swaging would be taking place.
I guess it would depend on the length and size of your 40 cal bullet maybe?
I pulled several of the bullets and they were still .401” if that tells you anything, and again I did this with 2 40 SW FCD’s to rule out the same argument.
I haven’t done this experiment with 45 yet as I don’t have the need to load them right now. But I will when the time comes.
All that being said, I still use Dillon crimp dies with everything but SD rounds…just to show my unbiasedness.
Lee Factory Crimp die for Handgun Cartridges and Cast Bullets
Quote:
Originally Posted by
robertbank
What size do you think we size our lead 9MM bullets? Nobody to my knowledge sizes them .355 like the plated or FMJ bullets are. We all size them either .356 or .357. Bullets sized as such cause a slight bulge in the 9MM case. Sized to either .356 or .357 they will run through every 9MM I own. The benefit sizing the bullets .356 ir .357 will ensure a tight fit of the bullet to the bore. When this occurs along with proper lube leading from gas cutting or tumbling from under sized bullets to bore is virtually eliminated. I do digress you probably already new that.
What folks use the FCD designed for pistol cartridges for is to run their bulged cases through the FCD to smooth out the bulged case. When they do that the reduce the size of the cast bullet. Properly resized the 9MM case will bulge out a bit when using lead bullets sized .356 or .357. If they don't in your universe you are indeed unique.
I am not sure you understand the issue.
Take Care
Bob
Jesus Christ this is painful.
You obviously haven’t read my post. Or maybe you have? At this point not sure.
MY .356 AND .357 BULLETS GO THROUGH THE LFCD WITHOUT BEING TOUCHED.
Not sure how much simpler to make it.
I’m guessing you haven’t actually tried it and are just assuming it your hypothesis. I think you might have a predisposition and personal bias towards believing something is true without actually testing it out?
OR if you have and you bullets are getting swaged it’s one of two things.
1-you are unlucky and got the undersized LFCD.
2-Your terrible at reloading.
Good day sir.
For the rest of you. FCD will most likely not swage you bullet, at least in 9MM.
Lee Factory Crimp die for Handgun Cartridges and Cast Bullets
Quote:
Originally Posted by
onelight
I am one of the folks that use it and I don't get a bulge with .356 or .357 bullets . If you get a bulge or not also depends on your sizer die.
This can also be true.
How you size, and what sizing die you use can have an impact on how oversized you final product is.
Also what you use to bell and how much you bell can have an impact on the size of your final product.
Lee Factory Crimp die for Handgun Cartridges and Cast Bullets
BTW.
I asked Lee.
The FCD is not designed to as Bob said, “smooth out the bulge” in your case.
The bulge in the case, at least as it’s being discussed here, is for the most part unique to 9MM because its tapered so much more than other straight walled pistol case.
Hence you get that coke bottle effect.
You can still get it in most straight walled pistol cartridges.
9MM, 40 SW, and 45 auto (as well as their variants) are all tapered to some extent.
When you put a bullet in the case, at least with 45 and 40, an oversized bullet is going to bring the taper at the top of the case more inline with the taper at the bottom of the case.
This creates the coke bottle effect which is so much more pronounced on a 9MM because the taper is so much more pronounced.
And probably why my experiment only really worked on the 9MM FCD.
The carbide ring in the 9MM FCD is so much larger than the mouth of the case, no matter what sized bullet you put in there, it can for the most part pass right over the case mouth and bullet.
The 40 SW FCD carbide ring is closer to the top of case diameter because there is only about .001” difference between the top and bottom of the case as.
The LEE FCD are designed as a final sizing to the lower 1/3 of the case to bring it back to SAMI spec (or maybe less).
Fired cases grow at the back of the case even in supported barrels.
Failure to chamber can be caused by any number of things but Lee determined that often times failure to chamber is caused by the base of the case not being sized down enough.
This is also why they use it in their “press though” sizing mechanism. It’s designed to bring the base of the case back to spec where most sizing dies do not reach.
This is also why they came up with the U Die. Same concept.
Now if you stick a .401 or larger .40 cal bullet in the case, or a .452 or larger 45 cal bullet in the case there is a good chance (depending on lots of other variables) that it will cause the case at the top to grow to the size of the case at the bottom. Hence the reason many people are getting swaging with calibers other than 9MM.
But as I said I’ve had .40 cal lead bullets that still measure .401 after being seated and pulled. So there is the possibility that you can get away with it.
I don’t see the need. I use a Lee U die and Dillon crimp in most cases for lead projectiles. But I also build most of test loads with a standard Lee sizing die and Dillon crimp die and have very few issues.
I have a theory (with no way to test or prove) that the FCD and Lee U die may cause accuracy issues, albeit minor, precisely because it’s sizing or undersizing the base.
It’s not apples to apples, but much like a rifle benefits from fire formed brass, when you squeeze the base of the case down it creates a small area for pressure to escape while the case is re expanding during firing. Hence the small degradation on accuracy.
And often times this extra sizing at the base of the case is unnecessary (even though I do it).
I have found that my loads not run through the u die or FCD are often times a touch more accurate. The difference is minor, but it’s there and it’s consistent.
I think the LFCD is meant to make sure that when you must absolutely have a a round that will chamber it does. But most of the time it’s not necessary.