Lee Loader

First I should repeat my comment from another post that I do not normally crimp rimless bullets but always crimp anything destined for revolver use. That was until this week when I reloaded 200 45 ACP with some straight sided jacketed 230 grain bullets. To get the bullets started I had to put a very slight flair on the case mouths. In getting my 1911A1 ready for the season I took advantage of the opportunity to do a drop test on these cartridges and sure enough they wouldn't fully chamber without a firm push. I ended up adjusting the seating die to add a light tapered crimp and ran all 200 through again. This fixed the problem. This experience has me reevaluating my crimping rules. I would be interested to know how others approach crimping of pistol rounds.

With the exception of the 256 WM and the 357 Herret (I don't shoot either very much these days) I taper crimp all of mine, 9mm, 357 Sig, 357 Mag, 45 ACP, 45 Colt and 380 ACP.

Make smoke,

I also taper crimp my 9mm. Wheel gun reloads too, of course.

I wonder if theres a break-point for how much pressure will cause enough recoil to create a dangerous amount of setback

In any case i find myself surprised with a taper crimp sufficing for 357

Pistol cartridges must not be crimped.

But the flare needed to seat the bullet should be removed. This can be done with a taper crimp die that is set to just touch the mouth of the case.

Fyodor wrote:Pistol cartridges must not be crimped.

But the flare needed to seat the bullet should be removed. This can be done with a taper crimp die that is set to just touch the mouth of the case.

That is also my take on the subject but I am wavering.
Most die makers sell a crimp die for rimless pistol cases. Lee has the tapered crimp built into their dies but still sells a separate "Factory" crimp die and includes the same in their 4 die sets. To my knowledge I have never seen a die made just to remove the seating flair. Several references suggest a crimp improves powder burn rates and consistency. BTW Lee says their built-in tapered crimp is"Modified" and their Factory crimp die has a button that returns the case to factory standards. I had to pull a pile of 9mm bullets that were cast slightly oversize and bulged the cases enough that they wouldn't chamber in my M&P9. Those cartridges went through the Factory crimp die at the end of the loading process to remove the mouth flair. It obviously didn't work as advertised.

I'm using the Carbide Factory Crimp Die with oversized cast bullets in the 25 Auto, 32 Auto, 380 Auto, 9mm Luger, 9mm Makarov, and 45 Auto. No problems. The only thing I do in the setup is to adjust the die reference a micrometer reading at the case mouth with the bullet seated. I know the diameter of the bullet and the thickness of the brass, so I bring the adjusting screw in until bullet diameter + case mouth thickness X 2 is achieved. That's it.

In this example from my 45 Auto, the groove requires a .457" bullet and the case mouth is .010" thick. So in the setup, I was to see all this come together at .477", nothing more or less.





I do not doubt that the CFCD folds the case mouth back within the limits of the expander plug in the Powder Through Expander Die. That would be easy to engineer. In the case of the 45 Auto, a .457 bullet is at the limit of the expander plug. If you are using the Universal Case Expander or a non-Lee Die, more than likely not. The Lee PTED plug controls expansion over a set depth so the CFCD easily can easily correct it in reverse.



As a note, Lee does sell over and under sizing dies, and I have an oversized die for my 45 Auto. Once you move into the other dies for expansion and beyond, it is all stock dies.

I load a bunch of different cartridges for a bunch of different guns .
Generally crimp is only sufficient to remove any flair for my use .

In 35 cal to date I've not found a need to do more than remove the flair , die maker not withstanding , in autos . I did find that with a particular powder I did need a fair crimp to get regular accuracy with 357 mag . I also found that the first and second to cycle cartridges in lever guns tended to need enough crimp to keep them from set back with a full tubular magazine .

45s have presented a different situation for me .
I have a PCC in ACP , I also have revolvers but no pistols . Fortunately having revolvers allowed me to take all of the light roll crimped ammo and put it in moon clips . I doubt there is any real difference between the loads or that the bullet would move in the revolvers but a 250 at 850 fps can be assertive at least for the cartridges themselves .

The Colts and Schofields get a crimp to prevent set back in the tube mags but only enough to do that .

I suppose I should also mention that everything I load is cast so even taper crimps are done sparingly .

I would venture that some die sets other than 45 ACP have a step in the seating die to also do a roll crimp on an auto case . I'm thinking along the lines of 38 short and 9×18 maybe sharing a die reamer . I would bet also that the 460 S& W has that capability .

My 9mm "practice" loads get a fairly heavy taper crimp and are very near max loads. Plunk test shows they do not go too deep and provides ample holding for good ignition.
38s and 357 mag get a good roll crimp except for the ones that I use Berry's plain bullets (no cannelure), these I use a taper crimp.

Back when my chronograph was working I found greater consistency shot to shot with slower powders in the 357 and 44 magnums if they had a tight crimp. Speaking primarily of H110 and WW296 and heavy bullets.

Make smoke,