Crimping for 9mm

[Black Jaque Janaviac]

I recovered some 9mm bullets after the snow thawed and I can see an extra ring in the bullet that is from the case mouth.

I use the Lee FCD and don't have any problem with leading at all. I do notice that during load development I get primer intrusion into the firing pin channel well before reaching max loads. I realize with an inertia pin such intrusion is not necessarily excessive pressure but it is a nuissance when bits of metal shave off and clog the channel. I have trouble trying to mimic factory velocities and or POI. Factory loads will exhibit the same extrusion but mild enough that it doesn't shave off metal.

So, would a lighter crimp keep pressures down so that I could get a little more velocity before the primer intrusion sets in?

258536

[DonMountain]

Stop using that "Factory crimp die" and get a proper taper crimp die so your headspace stays at a correct length. What you are doing may allow the cartridge to wedge into the end of the chamber for excessive headspace and increase pressures by dangerous amounts.

[Black Jaque Janaviac]

I'm pretty sure the FCD that comes with the Lee 4-die pistol set is a taper-crimp die. It is certainly not a roll crimp - so I shouldn't be having any headspacing problems.

[Black Jaque Janaviac]

Yep. From Lee's website:


Revolver dies roll crimp with no limit as to the amount. A perfect taper crimp is applied to auto-loader rounds.

[la5676]

Exactly. I have seen other posters suggest deep sixing the FCD. In no way does it roll crimp on any of the autoloader dies. I don't know where this rumor got started. I don't have a taper crimp die, but this comment from LEE's site about the TCD leads one to believe it would roll the case mouth more so than the FCD.

" These dies offer little or no advantage when used with 1986 or newer Lee Dies as the crimp angle is already a modified taper crimp. Jacketed bullets must have a crimp groove"

If it needs a crimp groove, it likely is rolling the case mouth into it.

[Walks]

I use the lightest taper crimp possible, just to keep the bullet secure in it's position in the case.
For revolver I use only a roll crimp, only as heavy as needed.

What I can't figure out is how we kept bullets secure in auto cases Before taper crimp dies came out in the late 1970's ?

For the main Three; 9mmLuger, .40S&W and .45ACP I adjust the Taper crimp to just "Kiss" the case mouth. Then load 10rds and put 7-10rds into the Mag. Fire 3rds and remove remaining rounds from mag. Check cartridge over all length. if C.O.L. is shorter then pre firing loaded C.O.L., I increase Taper Crimp only until bullet is secure in case. It's a simple trial and error. It does assume all cartridge cases are the same length or close to it.

[gwpercle]

Try switching your brand of primer to one with a harder cup , it will resist flowing into the primer pin hole better . Try CCI . Discard any brass with loose primers pockets...the primers should not just slip easily in the pocket... you want a good grip on the primer or the 9mm Luger pressure pushes it out .
Gary

[gwpercle]

I use the lightest taper crimp possible, just to keep the bullet secure in it's position in the case.
For revolver I use only a roll crimp, only as heavy as needed.

What I can't figure out is how we kept bullets secure in auto cases Before taper crimp dies came out in the late 1970's ?

For the main Three; 9mmLuger, .40S&W and .45ACP I adjust the Taper crimp to just "Kiss" the case mouth. Then load 10rds and put 7-10rds into the Mag. Fire 3rds and remove remaining rounds from mag. Check cartridge over all length. if C.O.L. is shorter then pre firing loaded C.O.L., I increase Taper Crimp only until bullet is secure in case. It's a simple trial and error. It does assume all cartridge cases are the same length or close to it.

I started reloading in 1967 and taper crimp dies had been around a lot longer than that , I'm sure they were not invented in the late 1970's , I'm still using the CH steel 9mm Luger dies I bought in 1967 to load ammo for my dad's WWII Walther P-38 ... and it came with a taper crimp die and I'm sure the 9mm die set had sat on the dealers shelf two or three years...almost no interest in the 9mm luger back then .
Gary

[Black Jaque Janaviac]

Exactly. I have seen other posters suggest deep sixing the FCD. In no way does it roll crimp on any of the autoloader dies. I don't know where this rumor got started. I don't have a taper crimp die, but this comment from LEE's site about the TCD leads one to believe it would roll the case mouth more so than the FCD.

" These dies offer little or no advantage when used with 1986 or newer Lee Dies as the crimp angle is already a modified taper crimp. Jacketed bullets must have a crimp groove"

If it needs a crimp groove, it likely is rolling the case mouth into it.

Huh. I never saw that on Lee's website. Probably because I only have FCDs for either my revolvers or my autos. The FCD included in the 4-die set applies a taper crimp. But it is considered an FCD because it has the carbide sizing ring.
But you're right - I don't know where the silly rumor that Lee's 9mm FCD (designed for semi-auto pistol) would apply a roll crimp? That would be monumentally stupid on Lee's part.

[tazman]

Just like any other taper crimp die, the Lee FCD can be adjusted to crimp too much. You want the boolit to be held firmly by the case. With a 9mm(and most other autoloading cartridges) the boolit is held by the case wall tension rather than the crimp. Over crimping does nothing to improve this.
I use the Lee FCD on all my handgun cartridges. I adjust the crimp on autoloading cartridges to just take the bell out of the case mouth. This is easily accomplished with the Lee FCD due to it's design. No need to loosen the die and lock it back down repeatedly in a search for just the right spot. A simple turn of the knob and you are there.
This can be accomplished on the first cartridge you load.
Since I load mixed brass and often times use fairly large diameter boolits, having the FCD in the finish crimp station keeps all my ammunition working like a champ for me.
I have never had a boolit sized down too much by any of my FCD dies.

[Burnt Fingers]

The carbide factory crimp die is the cause of more problems than any other die I've seen used.

That carbide ring will swage down lead bullets to way undersize.

[tazman]

The carbide factory crimp die is the cause of more problems than any other die I've seen used.

That carbide ring will swage down lead bullets to way undersize.

It never has for me. Maybe I managed to get some with larger carbide rings than most other people.
People claim Lee equipment is inconsistent. Perhaps this is one of those times.

[onelight]

The carbide factory crimp die has a different feel when adjusting and you have to check carefully when setting up your dies , thy feel differently on the press and it seems that if you are used to traditional crimp dies you may over crimp the carbide ring will remove all flare and most rounds will chamber in most guns with out running the crimp sleeve down , back the crimp off to none and then work up to the amount you want , they just take a little getting used to , but I prefer them in most of my auto pistol ammunition

[Black Jaque Janaviac]

The carbide factory crimp die is the cause of more problems than any other die I've seen used.

That carbide ring will swage down lead bullets to way undersize.

I have heard of this - however that is not a problem in this particular instance. I am just wondering if backing off on the crimp might reduce pressures a tad.

[gnostic]

I set my crimp die so that the loaded round, is in spec as shown in the loading manual. My primers aren't cratered and I'm getting zero lead in any of my pistols...

[megasupermagnum]

I have heard of this - however that is not a problem in this particular instance. I am just wondering if backing off on the crimp might reduce pressures a tad.

No. Unless you are crimping to some kind of extreme levels, adjusting your crimp will not lower pressures. A taper crimp isn't even a crimp, at least it isn't meant to be. It's only purpose is to remove the bell, and maybe just a touch more for sure function. What kind of primers are you using? Federal 100 primers are soft, and will flatten/extrude more than a CCI 500 all else equal.

[ioon44]

No. Unless you are crimping to some kind of extreme levels, adjusting your crimp will not lower pressures. A taper crimp isn't even a crimp, at least it isn't meant to be. It's only purpose is to remove the bell, and maybe just a touch more for sure function. What kind of primers are you using? Federal 100 primers are soft, and will flatten/extrude more than a CCI 500 all else equal.


Good advice here, the neck tension is what holds the bullet in the case. I use WSP primers and get rid of the Lee FCD.

[onelight]

I have never considered crimp as a contributing factor on the primer in auto pistols , not saying it doesn't affect it but what you describe I would consider to be more a consequence of the shape and size of the firing pin and firing pin hole in the slide , and or how hard the primer is , and or the pressure of the loaded cartridge produces in that particular barrel . The bullet weight , diameter , amount of bullet in the case , and powder selection and charge are what I look at that raise pressure .
The crimp on a cases that headspace on the mouth can't be so heavy that you don't headspace correctly , this can be difficult because most autos will headspace off the extractor enough to fire but probably not headspace correctly , but my concern is to keep the bullet at proper OAL ( not push back in the case on the feed ramp or in a jam ) in other words to stand the rough treatment that the cartridge gets in an auto . But I don't load for maximum velocity in my autos for 99% of my reloads I load for function and accuracy an don't much care what the velocity is. I don't hunt with mine and for defense I use factory loads so I have no need to press the envelope.
I have used the word "I" in all this only because it's what works for me , not because I have all the answers or even the best answer.

[mdi]

One of the problems with Lee's FCD for semi-auto cartridges is when too much crimp is applied, the reloader doesn't see the results. Most often too much taper crimp results in a case bulge. So, when there is too much crimp is applied and the case bulges, the bulge is hidden, swaged down, by the sizing ring as the cartridge is removed from the die, but the screwed up neck tension and or distorted crimp remains.

[onelight]

One of the problems with Lee's FCD for semi-auto cartridges is when too much crimp is applied, the reloader doesn't see the results. Most often too much taper crimp results in a case bulge. So, when there is too much crimp is applied and the case bulges, the bulge is hidden, swaged down, by the sizing ring as the cartridge is removed from the die, but the screwed up neck tension and or distorted crimp remains.
I have never experienced that but I suppose it could happen.
But some of us can screw up a crimp with any brand die on occasion .:grin:

[la5676]

One of the problems with Lee's FCD for semi-auto cartridges is when too much crimp is applied, the reloader doesn't see the results. Most often too much taper crimp results in a case bulge. So, when there is too much crimp is applied and the case bulges, the bulge is hidden, swaged down, by the sizing ring as the cartridge is removed from the die, but the screwed up neck tension and or distorted crimp remains.

You can accomplish the same overcrimping with a taper crimp die. If not adjusted right, you can almost make a 9mm loaded round look like a 357 Sig round. If one follows the directions on an FCD die, it's pretty hard to screw it up. The same can be said for any die. Ya gotta be smarter than what you are working with. I know people than can tear up an anvil with a rubber hammer. There is nothing wrong with the LEE FCD die if used correctly. Likewise for the TCD. I have both, but use the FCD die way more often, and have no issue with it whatsoever.

[Taterhead]

Is increased taper crimp the cause of greater pressure? No. In fact it can reduce pressure br wrecking the interference fit (neck tension) from excessive crimping.

Brass is springier than lead. So when the case mouth is squeezed by the die, the soft lead underneath swages down some. The brass springs back.

There is an experiment that will demonstrate this. Take an unsized and fired auto-loader case. Place a bullet to the normal depth. Might need a filler underneath to keep the bullet from falling in. At this point there is zero neck tension.

Gradually add more and more taper. Note that even an excessive crimp will barely keep the bullet from easily plopping out with a light blow from a kinetic hammer. Typically the bullet can be spun around by hand. The taper crimp die just doesn't do much for bullet pull. It can make a mechanical step to prevent setback, but that is a different mechanical process than creating bullet pull.

[fn1889m]

I have never experienced that but I suppose it could happen.
But some of us can screw up a crimp with any brand die on occasion .:grin:

Yep. I have overcrimped 9mm. It does bulge the case. I have also dented an anvil. It takes some time to learn that less is often better in fly tying and reloading.

[robg]

a light load can cause primers to back out if the pressure is low as the case can move about.

[onelight]

a light load can cause primers to back out if the pressure is low as the case can move about.
This is true , but I can't imagine a load light enough for this to happen that would cycle an auto pistol.

[1006]

I have had 3 different Lee Carbide Factory Crimp dies cause the same problem. 357, 45 Colt, and 9mm. They “Coke Bottle” the case with the sizing ring located in the bottom of the die. In the 9mm it actually squishes the bullet as it goes over it and pushes it out slightly, causing my COL to increase, kind of like shooting a watermelon seed by squeezing it between your thumb and finger until it pops out.

I have better results with traditional simultaneous, one step seat and roll crimp operations, and SEPARATE, two step seat and taper crimp operations.

People were reloading very successfully for a long time before the Lee Carbide Factory Crimp Die came out. I usually do not use them for pistols. I do like the Rifle Die, Lee Factory Crimp die for lightly crimping the case mouth back down after seating bullets that required a slight case mouth flaring before seating the bullet.

I like Lee Dies, just not the Carbide Factory Crimp Die pistol dies.

[1006]

Regarding the primer intrusion: you did not say what type of gun you are shooting, and it is hard to tell, without a picture, what you are having happen.

But, in addition to the things already mentioned, your gun may be unlocking just the smallest amount after primer ignition and firing, causing the firing pin to drag on the primer as the bullet begins to eject. Several things can help prevent this: replace the gun’s firing pin retraction spring if it is a hammer fired gun, replace the recoil spring with a heavier one if you have a striker fired gun. If the indent left in your primer looks elongated or teardropped try changing the springs.

[fredj338]

I doubt your crimp is affecting pressures much, unless you were already running max but still not likely imo. Just crimp enough to remove the flare. If you are denting the bullet, it is too much & can play havoc with accuracy.

[onelight]

I have had 3 different Lee Factory Crimp dies cause the same problem. 357, 45 Colt, and 9mm. They “Coke Bottle” the case with the sizing ring located in the bottom of the die. In the 9mm it actually squishes the bullet as it goes over it and pushes it out slightly, causing my COL to increase, kind of like shooting a watermelon seed by squeezing it between your thumb and finger until it pops out.

I have better results with traditional simultaneous, one step seat and roll crimp operations, and SEPARATE, two step seat and taper crimp operations.

People were reloading very successfully for a long time before the Lee Factory Crimp Die came out. I usually do not use them for pistols. I do like the Rifle Die, Lee Factory Crimp die for lightly crimping the case mouth back down after seating bullets that required a slight case mouth flaring before seating the bullet.

I like Lee Dies, just not the Factory Crimp pistol dies.
I have six sets with carbide factory crimp dies my revolver dies the carbide ring does not size anything I can push a fired case unsized case into it with finger pressure unless Lee has changed them something is wrong with yours.
My auto pistol dies do bump over a cast bullet they make the cartridge the same size as a factory load That is what it is designed to do. If you want over size ammunition it is the wrong die .

[Dapaki]

I hate to ask but have you measured the COL?

[Carrier]

I use FCD on every handgun I reload for. What I did for loading lead is have a FCD I knocked the ring out of so the case enters the FCD with no interference with over sized flat base bullets so the ring doesn’t swage the bullet. I like them for the simple fact of being able to adjust so much easier.
Am I a hack I don’t know but it works for me.

[Taterhead]

For the benefit of any new loaders tuning in, it would be useful to be specific when we're referring to the

"Factory Crimp Die": the tool that applies a crimp using a collet crimping mechanism

Vs

"Carbide Factory Crimp Die". This is a completely different tool that has a carbide sizing ring in the die mouth to "iron out" or post size any irregularities or high spots on the case. I will spare my thought on this controversial feature. The crimping insert might be either a traditional roll or taper, as the case may be. This tool does not use a collet.

Similar name. Completely different tools.

[onelight]

For the benefit of any new loaders tuning in, it would be useful to be specific when we're referring to the

"Factory Crimp Die": the tool that applies a crimp using a collet crimping mechanism

Vs

"Carbide Factory Crimp Die". This is a completely different tool that has a carbide sizing ring in the die mouth to "iron out" or post size any irregularities or high spots on the case. I will spare my thought on this controversial feature. The crimping insert might be either a traditional roll or taper, as the case may be. This tool does not use a collet.

Similar name. Completely different tools.
It is confusing that Lee calls them both factory crimp dies , I like and use both two more tools in the tool box .
The carbide crimp is for duplicating factory spec outside dimensions these will function in any gun just like factory assuming proper bullet choice and OAL if you need or want custom oversize ammunition it is the wrong die.
The collet die is a completely different product uses a collet to make the crimp , and to add to the confusion they also have collet sizer dies

[Burnt Fingers]

For the benefit of any new loaders tuning in, it would be useful to be specific when we're referring to the

"Factory Crimp Die": the tool that applies a crimp using a collet crimping mechanism

Vs

"Carbide Factory Crimp Die". This is a completely different tool that has a carbide sizing ring in the die mouth to "iron out" or post size any irregularities or high spots on the case. I will spare my thought on this controversial feature. The crimping insert might be either a traditional roll or taper, as the case may be. This tool does not use a collet.

Similar name. Completely different tools.

Many people get the two confused. I have no problem with the factory crimp die. I use a couple of them myself. However the Carbide FCD causes more problems than it solves. Even more when it's used on cast boolits that are oversized.

[Carrier]

Many people get the two confused. I have no problem with the factory crimp die. I use a couple of them myself. However the Carbide FCD causes more problems than it solves. Even more when it's used on cast boolits that are oversized.

Just have to knock the ring out if it does.

[onelight]

Many people get the two confused. I have no problem with the factory crimp die. I use a couple of them myself. However the Carbide FCD causes more problems than it solves. Even more when it's used on cast boolits that are oversized.
It does does what it is designed to do ,what causes a problem is when some one uses the wrong tool for the what they want to accomplish .

[GONRA]

GONRA runs all 9mm and .45ACP reloads thru LFC dies. (Load lottsa jacketed boolits.) Just make SURE all yer reloads PASS THE PLUNK TEST!
OVERSIZE Cast Lead boolit reloads - may NOT "pass the plunk test" or result in bulged cases, etc. so watchout.....

[WheelgunConvert]

Only for 9mm, I use a spacer cut from an old credit card (or similar) and set the gap between the shell holder and the carbide FCD. Then adjust the taper screw for a light crimp per directions. Because the Luger case is tapered, it will engage the carbide ring if the case is significantly larger but otherwise will not swage the projectile or cartridge. YMMV.

[megasupermagnum]

Only for 9mm, I use a spacer cut from an old credit card (or similar) and set the gap between the shell holder and the carbide FCD. Then adjust the taper screw for a light crimp per directions. Because the Luger case is tapered, it will engage the carbide ring if the case is significantly larger but otherwise will not swage the projectile or cartridge. YMMV.

But the carbide sizing ring isn't tapered, so what does that gain you? It's still sizing over the bullet.

For the record, I never once had a problem with the carbide sizers. .002" over sized cast bullets still do not size down in any carbide FCD I've tried. If it does, it's a simple task to smack the ring out of the die.

[cupajoe]

I was recently gifted a Lee Deluxe Pistol Die Set in 9MM Luger. A renter had left some reloading gear when he moved. This die set has the carbide factory crimp die. The carbide ring IS indeed tapered. .394 at the mouth and .381 in as far as my calipers will freely reach. I don't have any idea how well they work as I don't use a taper crimp. I don't know if these are older or newer dies or if all carbide taper crimp dies now are tapered.

[onelight]

Lee has the directions for die adjustment on the Lee sight . If your gun will shoot .355 / .356 cast bullets the carbide factory crimp works great . My 9s all will shoot .356 Hi-Tek with out leading if I keep velocities moderate.
You will just need to experiment a bit and see what your guns want. If your gun and or the load you want requires an oversized bullet if not cast hard you may need a standard taper crimp die , the bullet seating die will apply a standard taper crimp . Assuming of course it is a standard 4 die 9mm set.

[WheelgunConvert]

It keeps the fixed size ring higher on the case where it is smaller. Even if the ring is straight walled the geometry applies. Think of it as additional tolerance higher on the case.

YMMV- it works for me.

[1006]

The Lee Carbide Factory Crimp Dies that I have were purchased when they first came onto the market. So, they may have changed since then. I do not know. I have had problems with the 9mm, 357, and 45 Colt/LC.

[charlie b]

I love the Lee FCD's. I use them for my 9mm, .45acp and .357. Just adjust to suit your pistol.

[tazman]

I love the Lee FCD's. I use them for my 9mm, .45acp and .357. Just adjust to suit your pistol.

I agree with charlie b. I use them for all my handgun cartridges and have no issues like others have talked about.

[fredj338]

I use FCD on every handgun I reload for. What I did for loading lead is have a FCD I knocked the ring out of so the case enters the FCD with no interference with over sized flat base bullets so the ring doesn’t swage the bullet. I like them for the simple fact of being able to adjust so much easier.
Am I a hack I don’t know but it works for me.
Then you really no longer have a FCD.

[David2011]

Gradually add more and more taper. Note that even an excessive crimp will barely keep the bullet from easily plopping out with a light blow from a kinetic hammer. Typically the bullet can be spun around by hand. The taper crimp die just doesn't do much for bullet pull. It can make a mechanical step to prevent setback, but that is a different mechanical process than creating bullet pull.

I’ve shot autoloaders in competition since 2006, at least 100,000 rounds. All rounds were taper crimped and were held quite tightly. Three whacks to pull a boolit.


In general, crimping has several functions. It prevents setback. It delays boolit movement until some pressure is built, preventing the primer from dislodging the boolit and increasing powder burn consistency. It prevents the boolit from moving outward. It assures that the round will chamber correctly as the case headspaces on the mouth. If oversize, the case may not seat against the forward end of the chamber. If undersize, it can go too deep. At that point the boolit has been swaged undersize.

There is only one way to determine correct taper crimp. That is to measure it with calipers. A micrometer may measure a burr on the case mouth so I measure just behind the edge of the mouth. Specs are in the reloading manuals. Anything else is just guessing.

[Taterhead]

I’ve shot autoloaders in competition since 2006, at least 100,000 rounds. All rounds were taper crimped and were held quite tightly. Three whacks to pull a boolit. I don't talk about my round counts on public forums (just a personal thing), but it is a statistically significant number. I've been shooting and loading much longer than I've been a member of this forum. Both in range time, and on a timer. A bullet seated into a case with the correct inside diameter will take a similar force to dislodge the bullet due to the interference fit. That is neck tension at work. Same thing will happen if the bullet is pulled before crimping.



In general, crimping has several functions. It prevents setback. If crimping enough to create a mechanical step in the bullet, then yes. But I argue that a mechanical step in a plated or coated cast bullet is too far. But that is probably another discussion altogether.



It delays boolit movement until some pressure is built, preventing the primer from dislodging the boolit and increasing powder burn consistency. It prevents the boolit from moving outward.

Wholeheartedly agree with that if talking about roll crimps, but taper crimps have minimal affect on bullet bull. The easy experiment that I described above will isolate the effects of the taper crimp and will show that it does almost nothing for bullet pull. It's all about neck tension. If I can apply a "firm" taper crimp and still spin the bullet by hand, then the crimp isn't doing much for the retention of a bullet. Furthermore, as stated earlier, the bullet will pop right out of the case, even after applying a taper crimp. Light, medium, firm. Doesn't matter. Brass springs back more than lead and copper. Squeeze the case mouth firmly, the lead swages, and the brass springs back. Unlike a roll crimp into a cannelure or crimp groove, there is minimal mechanical "grip" from a taper crimp. Otherwise a taper crimp would be sufficient to prevent bullets from creeping in our revolver loads.


It assures that the round will chamber correctly as the case headspaces on the mouth. If oversize, the case may not seat against the forward end of the chamber. If undersize, it can go too deep. At that point the boolit has been swaged undersize.
Agreed. Exactly.



There is only one way to determine correct taper crimp. That is to measure it with calipers. A micrometer may measure a burr on the case mouth so I measure just behind the edge of the mouth. Specs are in the reloading manuals. Anything else is just guessing. I find of dimensions in manuals for case mouth ODs, but these are without crimps. Easy to deduce a crimp diameter from those nominal drawings, however. I don't believe that there is a SAAMI standard for taper crimp, but I could be wrong. Regardless, the outside diameter will necessarily increase if adding diameter with cast bullets, rendering the drawings a bit moot.

Tough to measure with calipers or micrometers. Subjectively, if it doesn't engrave the bullet with the case mouth and plunks into the gauge/chamber, that is a good taper crimp. Of course different makes of brass and different case lengths all impact the actual crimp applied (as you know). So we're looking for about an average that will work across the spectrum of mixed brass most of us use.

:drinks: