9mm, Something Unique or Old News/SOP

[Tilos]

OK, I have replaced the "crimp die" with a 9mm re-sizing die with the de-capper removed in my progressive.
Thankfully it has enough 7/8-14 threads to adjust it to just remove the case bell/flare, or as I like to call "de-flaring" not crimping.
It seems to be working as all ammo plunks in my tightest 9mm barrel, so far.
I won't bore you with pics as you can't see much/any difference from a round loaded with the usual crimp die or a FCD.

It this a common practice that just never gets mentioned?
Does anyone else do this or have tried it?
Do you see any potential problems?
Thanks for reading this post and posting here,

 

[CMV]

Comment deleted.

Sounds interesting.

 

[captain awesome]

Interesting. Have you tested for accuracy?

 

[Toprudder]

As you are only using it to remove the flare, I don't see any problem with doing it this way.

 

[Walkalong]

Why not use a cheap taper crimp only die? Or are you just using what you have? Sure, the flared entrance to a carbide sizer would work if carefully set up.

 

[LiveLife]

I have replaced the "crimp die" with a 9mm re-sizing die with the de-capper removed in my progressive ... Is this a common practice?

No, not a common practice.

can't see much/any difference from a round loaded with the usual crimp die or a FCD.

Why not use a cheap taper crimp only die?

+1 to what Walkalong posted.

Since you already have the FCD, you could knock out the carbide sizer ring from FCD to make it a "taper crimp only die".

AFAIK, the practice of knocking out carbide sizer ring is more common practice than using a resizing die as a taper crimp die.

 

[Wreck-n-Crew]

If your method of crimp is a sizing die (with the decapper removed) and just bumping the bell closed I suppose it could work without sizing the bullet down. Question is are you sure your not sizing the bullet down. Also you can accomplish a good "remove of the bell" with a standard taper crimp die (which is one of the most preferred methods) as previously mentioned.

For what it's worth I have used a 9mm die to flare the case mouth ever so slightly on my 300 Blackout cases. It worked fine. However it was not a necessary step. Proper case prep and a 309 case bullet slips right in with no peeling.

I have also used 9mm brass filled with lead and swaged it to .401" to work in my 10mm using parts from other dies such as my Pusher on my lee sizing die in a different die to swage in stages until I got to a point where I could just size it.

When it comes to swaging I over annealed the 9mm (that became the essential jacket for the 10mm bullet.) brass intentionally to make it softer but not so soft it came apart upon firing.

 

[Toprudder]

I think a more common usage would be another seating die to crimp, with the seating stem removed or adjusted high.

 

[Walkalong]

I think a more common usage would be another seating die to crimp, with the seating stem removed or adjusted high.

I have at least on set of dies were I do this.

 

[Tilos]

Thanks all for responding.
I have accumulated several sets of 9mm dies and a FCD that I can mix and match for different set-ups.
I have found the actual crimping angle of all of my 9mm taper crimp dies to be much steeper than the taper in any of the sizing dies and I tried this after taking a 9mm FCD apart, and looking at the angle that does the crimping.
When using that FCD I found the variation of range brass affected the amount of crimp and I was getting a crimp that was ideal, to a crimp that left a ring on the bullet, noticeable when pulled.

In the limited number of loads I've done using the 2nd sizer as a de-flare, I have not found any pulled bullets to have "rings" or bullets that were resized smaller, and all passed the plunk test.
That's the reason I'm trying this.

To clarify, that 2nd sizer is adjusted so the de-flaring is done up in the taper of the die, not the flared mouth entrance of the die.
I have not shot any rounds loaded this way because of weather conditions being wet and/or windy but all have plunked so far.
I'm not going to load many more until I have shot some, and will report back on the results.

 

[LiveLife]

I have found the actual crimping angle of all the crimping dies to be much steeper than the taper in any sizing die ... to a crimp that left a ring on the bullet

Then you are using too much crimp.

9mm headspaces on case mouth and for greater accuracy, I want case mouth closer to chamber wall to seal the gases faster.

With case wall thickness averaging .011" at top .100" below case mouth where most of taper crimp is applied, I usually add .022" to the diameter of bullet to just return the case mouth flare back flat on the bullet (and a touch more depending on the thickness of case wall). So for .355" sized bullets, I use .377" taper crimp and for .3555"-.356" sized bullets, I use .378" taper crimp - https://www.thehighroad.org/index.p...nd-bullet-setback.830072/page-3#post-10712225

Below is close up picture from "Let's talk about crimping the autoloader 9mm" thread of RMR 124 gr FMJ (sized .3555") loaded to 1.130" and .378" taper crimp applied with Lee bullet seat/taper crimp combo die seated/crimped in the same step. As you can tell from the picture, there is very gradual "taper" of case neck towards squared case mouth to headspace with chamber - https://www.thehighroad.org/index.php?threads/mixed-brass-effects-oal.824238/page-2#post-10605996

I too have several 9mm Lee die sets and currently have Auto Breech Lock Pro with separate seat and crimp operations but with jacketed/plated bullets, I really don't see a difference from seat and crimping in the same step.

 

[Walkalong]

I have found the actual crimping angle of all the crimping dies to be much steeper than the taper in any sizing die

A proper taper crimp die or seater with a proper taper crimp should not be. A roll crimp ledge is very sharp.

Hornady cheats on the inserts and use a compromise angle. It does a good "modified" roll crimp (Use one in .32 Mag to roll crimp) on the inserts for 9MM and .38/.357. It is way too steep for a taper crimp, as it makes adjustment for the taper crimp much to critical.

If that is what you have for "taper" crimping 9MM, get a good taper crimp only die. All the makers have one, and the Lee is cheap.

But what you are doing will certainly work.

 

[Walkalong]

A "Modified" roll crimp using the Hornady insert with the "compromise" angle on it, with its angle kind of halfway between the traditional taper and roll crimp ledges in dies.




.

 

[Rock185]

Tilos, I've loaded 9mm for a very long time, but haven't done as you describe. It would seem to me that in using the size die, you have essentially created a very long, gentle taper crimp. You'll have to test to make sure, but I don't see why it wouldn't work.

 

[Walkalong]

created a very long, gentle

That is by very definition a standard taper crimp.

 

[Tilos]

Tilos, I've loaded 9mm for a very long time, but haven't done as you describe. It would seem to me that in using the size die, you have essentially created a very long, gentle taper crimp. You'll have to test to make sure, but I don't see why it wouldn't work.

Thanks for responding
Yes, you get it, a gentle de-flaring at a much shallower angle.
Try it, it could work out to be an improvement over the usual tamper crimp die/FCD.

 

[mdi]

The OP must have a gun with a pretty tight chamber. Or something else is causing cartridges to not plunk. I've only been reloading 9mm for 12-13 years but I have never had to resort to extraordinary methods to make them fit my 3, 9mm pistols. I use a Co-Ax (and before that a turret) and use a dedicated, easy to swap out, taper "crimping" die (aka "Deflaring die"). All my dies are adjustable, so the "sharp" taper is inconsequential, and I have even produced some quality ammo for a semi-auto using a roll crimp die to deflare the case after seating, I just adjust it so it does not apply too much crimp. Because I use a lot of cast bullets I would be cautious about swaging down the bullets if I F/L sized after seating...

I used to have an FCD, but it now resides in a landfill somewhere in So. Oregon...

 

[Dudedog]

I have also used 9mm brass filled with lead and swaged it to .401" to work in my 10mm

Making bullets I assume.