9mm crimp

[Dieselhorses]

If a 9mm luger fires from a semiauto pistol/rifle, why on Earth do they sell factory "crimp" dies? I accidentally ordered one of these when I was, in fact, meaning to order the "tapered crimp" die. Also, why do they sell .355/.356 bullets when everyone says that they are too small for 9mm, and they prefer .358?

[lotech]

You don't need a FCD if you're doing everything right. I've found a taper crimp die works fine for cast bullets in the 9mm.

.355" bullets will work just fine in 9mm as long as they are jacketed bullets, not cast. Cast bullets need to be a little larger in diameter than bore size and that's not for just handgun cartridges, it applies to rifle bullets as well. Dependng on the gun, .357" or .358" diameter bullets seem to work best. There are always exceptions; maybe there are some 9mm pistols that do well with .355 cast bullets, I'm just not aware of any.

.356" cast bullets will work in 9mm, but you'll likely see less than ideal accuracy and it may be necessary to regularly remove bore leading, but they're safe to use.

[Dieselhorses]

Thanks, lotech for info. Just trying to find the purpose of the fcd. Would the fcd be a "roll crimp"? And would seem to be for rimmed cartridges? Sorry, even if I don't currently use something, i want to know it's applications.

[mehavey]

FCD for rimmed/roll is different than FCD for straightwall rimless (e.g., your 9mm).
I prefer standard roll crimp for former, and only use the latter for cast Legend/Bushmaster (etc)

[lotech]

Thanks, lotech for info. Just trying to find the purpose of the fcd. Would the fcd be a "roll crimp"? And would seem to be for rimmed cartridges? Sorry, even if I don't currently use something, i want to know it's applications.

I have found some very limited usefulness for the FCD when loading .32-20, a cartridge I only load every few years. Winchester .32-20 brass and Remington .32-20 brass are considerbly different in length, at least the batches I have are different. After seating bullets, I don't re-adjust the crimp die for the two different lengths, I just use the FCD. This probably wasn't the intended purpose for the die, but it has worked well for me. If you examine one of these dies and play with it a little on some dummy cartridges, you'll quickly see how you could easily get into trouble by overcrimping, distorting the case neck and resizing the bullet. Many handloaders crimp way more than is necessary anyway. The FCD makes overcrimping much easier. If you can get by without this die, and you probably can, that's the best approach. However, used properly (minimally), it shouldn't do any harm, but only you will know if that's true for your situation.

[Dieselhorses]

FCD for rimmed/roll is different than FCD for straightwall rimless (e.g., your 9mm).
I prefer standard roll crimp for former, and only use the latter for cast Legend/Bushmaster (etc)

So an FCD does something between a roll crimp and a taper crimp?

[mehavey]

https://support.leeprecision.net/en/knowledgebase/article/carbide-factory-crimp-explanation
. . . . The type of crimp on the die depends upon the type of cartridge.
. . . . With cases that headspace on the case mouth such as the 45ACP,
. . . . the die essentially reduces the outer diameter of the case mouth
. . . . into the bullet. On other cases, a roll crimp is applied.

and in actuality, two dies can be of completely different design depending on specific cartridge

[Dieselhorses]

https://support.leeprecision.net/en/knowledgebase/article/carbide-factory-crimp-explanation
. . . . The type of crimp on the die depends upon the type of cartridge.
. . . . With cases that headspace on the case mouth such as the 45ACP,
. . . . the die essentially reduces the outer diameter of the case mouth
. . . . into the bullet. On other cases, a roll crimp is applied.

and in actuality, two dies can be of completely different design depending on specific cartridge

makes sense. I believe the .45 acp is straight walled but the 9 is slightly tapered so not dependent on head spacing in chamber?

[mehavey]

Both headspace off the mouth.....

When you have rim, headspace off the rim.
When you have shoulder, headspace off the shoulder.
When you neither rim nor shoulder . . . :wink:

[Huskerguy]

I guess I am slow today and not completely following your question.

The Lee FCD which I use is a roll crimp for 38/357, i.e. revolver rounds and is a taper crimp for my 9mm. Some people like them, others swear at them and adjust their crimp with their seating die which I also do. The die manufacturer builds that into the die so you aren't going to roll crimp with a 9mm die set.

The crimp on a 9mm, for me, is the most critical aspect of loaded that round. Too much or not enough crimp lead to problems so using the data measurements in a book are key, not just going by looks like I can with a 38.

As for bullet size, the answer given above is spot on. Much depends on the material of the bullet. I reamed my Lee sizing dies out so my coated bullets size right at .3575 which works for my CZs.

[mdi]

"The crimp on a 9mm, for me, is the most critical aspect of loaded that round. Too much or not enough crimp lead to problems so using the data measurements in a book are key, not just going by looks like I can with a 38".


I've been reloading semi-autos for a while and I do not crimp in the "normal" fashion. Since neck tension is what holds semi-auto bullets in place, there is no need to "swage" the case tightly on the bullet. I tried measuring case mouth OD post "crimping", but found little value. I just deflare the case mouth enough to get 100% plunking using a taper crimp die (aka "deflaring die"). This has worked quite well for me on 32 ACP up to 45 ACP in 11 semi-auto handguns. K.I.S.S.! Don't overthink "crimping" semi-auto handloads...

[45_Colt]

If a 9mm luger fires from a semiauto pistol/rifle, why on Earth do they sell factory "crimp" dies? I accidentally ordered one of these when I was, in fact, meaning to order the "tapered crimp" die.

I take it this is a Lee FCD? If so they only sell the carbide FCD for the 9mm (may change down the road).

In this case it does two things. 1st is that it removes any flare from the case mouth via a taper crimping. And depending upon how the die is adjusted, further taper crimp the case mouth into the bullet. Which usually isn't required.

The 2nd part of the Lee carbide FCD is that there is a sizing ring, made of carbide, in the lower part of the die. Its purpose is to reduce the case size, even swage the bullet if oversize, so that every round will seat/plunk into a properly sized chamber.

There is a real mixed response to whether this die is necessary or not. It does have its pulses and minuses. So it really comes down to whether the user wishes the secondary sizing or not.

Doing a separate taper crimp is helpful when seating cast bullets. As it helps prevent the slicing of lead off the bullet as a single seat/crimp die can do.

45_Colt

[fredj338]

They sell 0.356 because people buy them. All my 9mm will run a 0.356, but i size 0.357 just to be sure in multiple, modern guns. I found no accuracy gain or leading reduction with 0.358.

[Dieselhorses]

So, I gather from all responses (which I am grateful for!), that it really depends on what a certain gun likes. From a global standpoint, I'll just treat my 9mm rounds as 45 acp's and do a slight taper crimp. Didn't mention but I'll be shooting these from a BCA 10.5" upper. Starting to wonder if I could load my lighter cast .358 pills for 9mm.

[wv109323]

IIRC, the Lee FCD was originally sold to increase accuracy mostly on rifle cartridges. It was suppose to correct bullet run out. It was to "hold" the case straight and then crimp the bullet concentric with the centerline of the case/bore.
I don't think there is any advantage of the FCD over a taper crimp die on pistol cartridges.

[243winxb]

From Lee
The carbide factory crimp die crimp style is a taper crimp for all auto loading handguns.
https://support.leeprecision.net/en/knowledgebase/article/carbide-factory-crimp-die-crimp-style


The rifle type is different.

[AlaskaMike]

The instructions that come with your 9mm carbide factory crimp die are much more concise and clear than the misinformation and confusion contained in a forum thread.

Just a suggestion.

[Dieselhorses]

The instructions that come with your 9mm carbide factory crimp die are much more concise and clear than the misinformation and confusion contained in a forum thread.

Just a suggestion.

They are. They just didn't say anything about that it's recommended to keep the bullet from entering the case during cycling, affecting accuracy or for pressure purposes.

[charlie b]

Probably because those are the reasons you use a crimp die. The links are Lee descriptions of the crimp dies. Lee does go a bit overboard with the rifle die and accuracy claims. I have had a couple rifle loads that did better with a crimp, but most do not.

I reloaded many years without ever crimping a load. Now I crimp all pistol loads, but no rifle loads (all bolt action).

https://leeprecision.com/reloading-dies/hand-gun-dies/lee-carbide-factory-crimp-die

https://leeprecision.com/reloading-dies/rifle-dies/factory-crimp-die

[mdi]

They are. They just didn't say anything about that it's recommended to keep the bullet from entering the case during cycling, affecting accuracy or for pressure purposes.

In semi-auto cartridges the neck tension keeps the bullet in place, not necessarily the taper crimp. I have been reloading semi-autos for roughly 28 years and do not crimp any. I just deflare the cases with the "deflaring die" (aka taper crimp die). With proper neck tension there is normally no set back, at least for the 4 semi-auto rounds, in 9 pistols, that I reload.

There is often a lot of "confusion" in threads about Lee FCDs. There are basically two types; for rifle/bottle neck cases a collet crimp die is used (also for a few straight walled cases, I have one for 44 Magnum). For "straight walled" cases a "post crimping sizing die" is used, an adjustable crimp die with a carbide ring for sizing before/after a crimp is applied. I am using a Lee FCD for my 32 H&R now because that is what came with the set and I haven't researched any profile or standard roll crimp dies. My handloads don't need any resizing but that's what I have for now, and my cast bullets aren't swaged down by the ring...

[jdgabbard]

The one think I find useful about the 9mm FCD is in de-Glock-ing brass before running them through the loading process. I've never had a problem with taper crimps in the 9mm, but the FCD does help with Glock bulges in the lower case on 9mm brass picked up from the range.

[armoredman]

I have been loading 9mm cast boolits sized .356 for 20 years or so, no problem. However, the Lee Factory Crimp Die I won't use on bare cast. I do use it on jacketed bullets, and all it does is smooth out any bumps in the case that might hinder chambering. Never had any problems with it.

[Martin Luber]

I have been loading 9mm cast boolits sized .356 for 20 years or so, no problem. However, the Lee Factory Crimp Die I won't use on bare cast. I do use it on jacketed bullets, and all it does is smooth out any bumps in the case that might hinder chambering. Never had any problems with it.with what pistol sir? Many are in the .358 range, few are .355. I got a 92FS that was said to be shot out, no rifling. Indeed, there were none. But after deleading it, the rifling reappeared. Commercial cast 355 to blame here. The Lee FCD makes a good sizer die and you can machine a plug for decapping pin. Their dimensions are not right for lead, die is too small and it swages the boolet.

[Dieselhorses]

with what pistol sir? Many are in the .358 range, few are .355. I got a 92FS that was said to be shot out, no rifling. Indeed, there were none. But after deleading it, the rifling reappeared. Commercial cast 355 to blame here. The Lee FCD makes a good sizer die and you can machine a plug for decapping pin. Their dimensions are not right for lead, die is too small and it swages the boolet.

I would agree with that, just from my experience-lead too hard and too small of a diameter thus not allowing obturation. resulting in keyholing and such. I powdercoat everything which allows me to go low on the BHN. 9mm j-words has me flabbergasted since they’re offered in 2 or 3 diameters. I guess it depends on your guns liking.


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[armoredman]

with what pistol sir? Many are in the .358 range, few are .355. I got a 92FS that was said to be shot out, no rifling. Indeed, there were none. But after deleading it, the rifling reappeared. Commercial cast 355 to blame here. The Lee FCD makes a good sizer die and you can machine a plug for decapping pin. Their dimensions are not right for lead, die is too small and it swages the boolet.

All of them. CZ and Ruger. No issues for decades. In the last 15 years I have powder coated them, and sized after powder coating, Lee .356 push through sizer. No leading issues. A couple of random target photos with P-10C - I cannot remember the distance, probably 15 yards or so. At work, no access to other pics right now.
https://i.imgur.com/FUCoe91.jpg

https://i.imgur.com/LbXHkQo.jpg

[armoredman]

I would agree with that, just from my experience-lead too hard and too small of a diameter thus not allowing obturation. resulting in keyholing and such. I powdercoat everything which allows me to go low on the BHN. 9mm j-words has me flabbergasted since they’re offered in 2 or 3 diameters. I guess it depends on your guns liking.


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MY J-word are all .355 over the years, and I have used cast sized to .358 that were given to me, but I have all sized my own cast down to .356. Slugs that I size to .358 I use in .38 Special. ;)

[Dieselhorses]

MY J-word are all .355 over the years, and I have used cast sized to .358 that were given to me, but I have all sized my own cast down to .356. Slugs that I size to .358 I use in .38 Special. ;)

Ok so dumb question, why ate j-words sold in .356 also?


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[243winxb]

MY J-word are all .355 over the years, and I have used cast sized to .358 that were given to me, but I have all sized my own cast down to .356. Slugs that I size to .358 I use in .38 Special. ;)

Most 9mm Luger AR types are straight blowback. They may fire out off battery, if bullet diameter is larger then the chamber throat.

Pistols, for the most part are delayed blow back, not all. They dont fire if action is not locked.

A standard taper crimp is all thats needed. But neck tension needs to be about .003"

[elmacgyver0]

I guess I'm about the only one here that likes the factory crimp die.

[armoredman]

Ok so dumb question, why ate j-words sold in .356 also?


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Why? Why not? It's a big diverse world.

[1006]

Hornady sells a .356 HP

[AlaskaMike]

I guess I'm about the only one here that likes the factory crimp die.

Nah, I like it as well. I use it for every semi auto cartridge that I reload for, just like I use a Redding profile crimp on every revolver cartridge I reload for.

I tend not to post about it much anymore because of the rampant badmouthing some folks here are prone to do regarding it.

[gifbohane]

My 2 cents The Lee "Factory Crimp die" is a brilliant marketing strategy, along with the "Perfect Powder measure."

It will only serve to correct any errors in my reloading processes. So, I save the money and reload correctly.

[Tripplebeards]

The lee factory crimp die works great in my 9mm with out issues but in the 10mm it shrinks my boolits to .400 just by inserting my load up into the die without any crimp applied. Jury is still out on the 10mm experiment but I’ve found that using my Hornady crimp die the largest I can keep my 10mm boolits are .403” with an outside case neck of .425” to get my ammo to plunk properly. Any larger case neck and my loads are to large and wont drop all the way into my chamber. I loaded up some .425” case neck diameter rounds but till have to test them for leading.

[michael.birdsley]

I like the Lee FCD die. I use it for for cast and boolits. I have it for my 9mm along with a lot of my rifle die sets. I generally shoot for .003-.004. Crimp.


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[SoonerEd]

By 9mm I presume you mean Luger. My 9 mm Kurtz (AKA 380 ACP) are smaller diameter than typical Lugers. I run .356 bullets in my 380's as they measure .355 where my Lugers measure .356 & one is a .357