Factory Crimp

[Bucksnort1]

At Cabelas' earlier today, I purchased Lee 30-06 and 44 magnum factory crimp dies. The package is labeled as a factory crimp." I looked for a 38/357 factory crimp die but didn't see one so I tried ordering at their new pricing/ordering kiosks. I searched for .357 factory crimp dies and was taken to a page where these are located.

The general description of these dies indicate they are "factory crimp dies"; however, when I scrolled down to look at the ones available, none of them, in the description column next to the caliber, mentioned factory crimp. For example, the 38/357 description is, "roll crimp." Other calibers called for taper crimps. None of the available calibers mentioned anything about factory crimps.

I sought advice from their reloading expert but I did not get what I consider the definitive answer. I think he was/is confused about the differences in crimps. It is possible, however remote, I could be wrong and a taper and roll crimp are actually factory crimp dies.

Does anyone have a clarification on this?

 

[Shootest]

Factory crimp is a name Lee gave to a type of die and not used by other manufactures. The factory crimp dies for rifle calibers are not like those for pistol calibers.
Lee’s factory crimp die for 357 mag will roll crimp the case.

A roll crimp is when the mouth of the case is rolled over into the cannelure. Used mostly on revolvers where the headspace is determined by the rim thickness.
A taper crimp is when the mouth of the case is squeezed onto the bullet. Used mostly on automatics where the headspace is determined by the mouth of the case.

 

[Nathan]

In revolver, factory crimp means roll + outside resizing.

In auto, factory crimp means taper + outside resizing.

In rifle, factory crimp means collet crimp.


Frankly, I like them, but not sure they are required.

 

[Pathfinder45]

I have three of them. I consider the one for 30-30 a must-have item. The other two are both for 45 Colt, but they are completely different. One of them is the typical Lee factory crimp for revolver cartridges, and, as has been mentioned, it works differently from their rifle crimp dies. The other one is a special order item made by Lee for Ranch Dog, from whom I obtained it, and it is a collet-crimp just like their rifle crimp die. I like it better, but I use both for different applications. I dont crimp bolt action rifle cartridges like 30-'06 or 270, at all.

 

[Bucksnort1]

Thanks for the clarification. Cabela's should re-word their description to include what you have said. They don't need to be wordy but just enough to clear up confusion.

 

[Nathan]

Possibly Lee does not want that written that clearly in advertising. It sounds less exciting than their talking points about their dies.

If you have read Lee's talking points, you would think dippers and a collet die have set every world record for accuracy.

Funny thing is most REAL accuracy happens with un-sized brass or custom FL sized brass using an arbor press. Read about benchrest rifle shooting. . .that is where you are talking about 5 shots into .1" at 100 yds.

 

[JeepHammer]

Just my experience here,

The three rules in life,
1. Application.
2. Application.
3. Application.

If you have any questions, see rules 1-3.

-----

Anything that feeds from a tube,
As pointed out, .30-30 is a prime example,
Needs a crimp.

Semi-autos that bang the crap out of the round getting it into the chamber needs a crimp.

Anything that flairs the case to accept the bullet need a crimp,
At least to the point where the case is straight again, if not a little more.

How you get that crimp is your choice.

Handgun rounds, straight case rounds are almost all a 'Taper' crimp,
Where the seating die just pushes the sides of the case IN against the bullet, a gently decreasing bore size in the die.

The Cartridge comes out with straight sides, (if you didn't under size the case in the first place when doing resize),
The bullet is gently but firmly held in place,
And the rounds simply 'Look' good when they come out.

-----

Most bottle neck rifle dies, and some pistol dies will have a 'Roll Crimp' cut into the seating die.

This is a lip cut into the die at a sharp angle,
Intended to turn the very end of the case mouth into the bullet to bite into the bullet.

I limit the use of these to cast lead bullets myself...
I'm not crazy about cutting into the jackets, deforming my bullets half way down,
But like I said, this is my personal preference...

This is not a gentle squeeze in a roll crimp die...
The since the cartridge is moving up, seater is pushing down on the bullet while the crimp ridge is pushing down/in (sharp angle shoulder)
You get a bullet with the jacket being skinned for the distance the bullet travels down into the case during the crimping process.

The down side to this particular type crimp is the PUSHING DOWN on the case, and deforming the bullet/jacket to a lesser extent...

Pushing down on the MOUTH of the case often crushes the shoulder of the bottle neck cases,
In straight cases, it budges the sides IF your cases aren't trimmed to EXACTLY the same length...
Long cases get crushed/bulged, short cases don't get crimped.
Without EXACT case length, and ZERO play in the dies/press, you wind up with INCONSISTENT crimps.

Inconsistent crimps is why bench shooters don't use a crimp... or they use a LIGHT taper crimp.

-----

The Lee 'Factory Crimp' die pushes IN on the sides of the mouth of the case.
It uses a completely different process in the die,
The die is TWO PIECES,
The fixed portion in the tool head, and a floating collet that contacts the shell plate.

When the floating collet contacts the shell plate, it's pushed up into a taper,
The force of contacting the taper pushes the collet jaws into the SIDES of the neck on the brass.
The force comes in from the sides evenly.

No more crushed cases, no shoulder collapse on the longer cases,
No more 'No Crimp' on the shorter cases,
Evenly applied crimp to all rounds without trimming all the cases to EXACTLY the same length.

It also takes the random part out of the process,
The press having a little wear, the tool head having a little slop, uneven case neck thickness doesn't matter, so no turning case necks on 'Non-Bench Rifle' ammo...

Since the collet fingers are above the taper,
Stuff like slightly oversize/undersize bullets, or different case neck thicknesses, which you would have to use a micrometer on EVERY bullet, and EVERY case neck to find the total diameter...
You can use this thing and NOT get uneven crimp pressure...

It's NOT for bench rifle ammo...
It's for PRODUCTION ammo where the guy doesn't want to cut every case every time he loads,
Where he wants to use every bullet that came in the box, instead of sizing each one,
It's for the guy that DOES NOT measure/cut every case neck for thickness.

It has it's place, and it works very well in that 'General Ammo' category it was designed for.

I use it on 'General Ammo/Varmint' rounds, and it does well in both .308 and .223, shooting well under 1 MOA,
All the while NOT cutting cases, sizing bullets, shaving case neck thickness, or worrying about all the stuff 'Bench Rifle' shooters do...

NOW, the down side,
Your case mouth WILL crack, depending on the particular brass you are using...
The extra pressure/working WILL harden the case mouth and unless you 'Anneal' the cases, the case mouth will harden and crack.

I DO NOT anneal 'General Ammo' cases, I don't see a point in cutting more than once (to minimum length), and shooting general ammo cases until the crack.
No trimming, no micrometers, Just, "Clean, Load, Shoot",
Toss when the mouth cracks...

Usually 6 to 8 loadings for me before cracks start when you use a light to moderate crimp.
Hard crimps will crack the case faster, but that is to be expected...

Since my 'General Ammo' is usually range pickup, once fired military, ect.
There isn't much invested in the cases, and they will never be 'Bench Rifle' cases,
I just don't see the point in treating them like they are bench rifle cases I paid $1 to $3 bucks apiece for.

They were free up to about 5¢, and if you get 6 or 8 loadings, that's under 1¢ per firing.
A pretty good deal in anyone's book...

 

[Nick_C_S]

Good read JeepHammer.

 

[Bart B.]

You can use this thing and NOT get uneven crimp pressure...

How is crimp pressure measured to verify its uniformity and separates it from the rest of the case neck grip on the bullet jacket?

 

[Peter M. Eick]

One of the resellers had Lee make Collet dies for revolver rounds. I forget who did it but I know it was done. I keep wondering about getting a set for 357 magnum just to play with.

 

[mikld]

For a new reloader; K.I.S.S.. If you are reloading for a revolver, get a dedicated roll crimp die (not a Lee FCD). If you are reloading for a semi-auto pistol, get a dedicated taper crimp die (not a Lee FCD). Learn to adjust your dies correctly and there is no need for an FCD.

The FCD for rifle cartridges (and some custom dies for handguns) are collet dies. Completely different animal and I have used them for my .223 and 30-06 semi-auto rifles. The collet squeezes the case mouth and no re-sizing of the case takes place.

I'm not a Lee hater, I just have tried the handgun FCDs and find them worthless and in my .44 Magnum it actually made my ammo way less accurate! It now resides in a landfill somewhere in Southern Oregon. If there is a chambering or crimping problem, find out why it's happening and correct it, don't just hide it.

My dos centavos only...

 

[Bart B.]

Sierra Bullets proved in the 1950's that any crimp on rifle cases unbalances bullets enough to degrade accuracy. Sierra doesn't test their bullets with cannelures in crimped cases for accuracy; they know better. As has other people shooting all bullets most accurate. It adds another variable. Whether or not one will notice is something else. Sierra dubbed crimping a "necessary evil" that has to be done sometimes because of ammo handling, rifle recoil, feeding issues and other stuff that happens before the round's fired. A compromise that helps some shooting systems.

 

[the led farmer]

Crimp is a variable just as much as powder charge, powder type, bullet weight, bullet type, OAL etc., etc. and must be experimented with for best results.

 

[skizzums]

a roll crimp has a ring inside the die that "rolls"(bends is more accurate) the mouth of the case into the cannelure or crimp groove. a factory crimp die is a collet that puts about a 1/16 of even pressure around the case mouth and squeezes it tightly around the bullet. i use FCD when making AR15 ammo for extra security for bullet setback which i had happen with "factory" reloaded ammo in the past.


collet for rifle. roll for 357 on right, just the crimp ring from die.

 

[mikld]

The FCD collet crimp dies are rifle only except for special order. The FCD for handguns use a roll or taper. Big difference...

 

[Peter M. Eick]

http://leeprecision.com/357-magnum-custom-collet-style-crimp-die.html

Here you go.

I should really order some of these just to try it out.

To bad they don't do a 38 special version.

 

[skizzums]

that would do fine on a 38spl

well....unless they made it too deep to engage the .38, but I doubt they would do that.

 

[joneb]

I am fine without a FCD for revolver and pistol, it appears to be a solution to a problem that should not exist. The FCD for rifle is a whole different critter.

 

[TimSr]

Of all the revolver loads I've done for years, 38, 357, 44, 45LC, 454C, I've never run into any situation where the roll crimp die that came in the 3 die set did not do the job wonderfully when adjusted right, and that ever made me feel the need to go buy a special crimp die.

For that matter, same with taper crimp semi autos.

The only rounds for me that could have had better options were some of the bottleneck rifle cartridges, or possible semi auto cartridges being shot from a revolver of which i have none.