Crimping 9MM Luger Cases for
HOW MUCH CRIMP ON A
9MM RELOAD? General consensus is that
"crimping" for 9mm Luger cases is not required and is a
misnomer. For 9mm Luger straight wall pistol cases it is close tolerances and press fit (case mouth
tension) that holds the bullet to the case. An actual crimp
is not needed and should not be used. All that is required
during the "crimping process" is to flatten the case mouth
flare against the bullet to allow it to load and eject
smoothly during the firing process.
"crimp" or flattening of the flare against the bullet may
result in loading or ejection problems. Too much crimp may
hold the bullet to the case too tightly causing the
dangerous condition of excessive pressure buildup. If the
bullet is deformed during the crimping process then too much
crimp has been applied and the crimping die should be
above photograph shows two factory Blazer Brass 9mm Luger
FMJ bullets that were removed from live unfired rounds
for inspection purposes. Both bullets were removed easily
with one tap with a bullet puller. The bullet on the right
was removed from a 9mm Luger reloaded round. It took four
hard hits with the bullet puller to remove the reloaded
bullet from the case. Note the deformity of the bullet. This
one was probably crimped a little too much.
Setting Your Die for
The best way I know to properly set
up your taper crimp die is first resize a
casing and measure the mouth diameter with a set of
calipers. Now take that empty casing and run it through the
crimp die and measure again. The two measurements should be
the same, or up to .002 smaller. Remember though less is
more when it comes to taper crimping.
Inspecting the Crimp
method to determine the proper setting for your crimp die is
to reload a dry round (no ammo or primer) on your reloading
press. Rub your finger against the side of the completed
round at the point where the case mouth contacts the bullet.
If the case mouth lies flat against the bullet, that's good.
Compare it with factory loaded ammo of the same caliber.
Next, pull the reloaded round apart with a bullet puller.
Then pull a factory loaded round apart. Examine both bullets
using the factory round bullet as a baseline for comparison.
If you have too many markings on your reloaded bullet or if
your bullet is deformed in any way then adjust your crimping
die accordingly and repeat the process until it looks like
the factory loaded bullet.
To "test" the crimp you have for
your reloaded 9mm Luger ammunition die settings, make up a
dry rounds (no
ammo or primer)
. Load them into your handgun
magazine. Chamber the first one, then pull the slide back to
eject it. Do the same with all of your dummy rounds and
verify smooth loading and ejection of the cartridges (no
snags or hang-ups)
9mm Luger or 9mm Parabellum Crimping
"Recognize that when talking about a semi-auto rounds
the headspaces on the case mouth that CRIMP is not the
way to keep the bullet in place. Case mouth tension
keeps the bullet in place. Crimp, in 9mm at the load
bench, is merely a way to repair the belling you did to
the brass when you flared it to accept a bullet. First
step-- don't flare the case mouth any more than you need
to. It shouldn't look like the bottom of the liberty
bell. Just a slight flare will prepare the brass to
accept a jacketed bullet. A little more flare is
necessary to accept a cast lead bullet. Next, use a
little crimp-- enough so that your loaded round falls
easily IN to the chamber of your pistol, and drops
easily OUT of the chamber of your pistol. Do that and
don't consider using any "crimp" to hold the bullet in
place in 9mm. That's not the purpose of it. Everything I
just said is basically the same thing
Cloud peak posted, I just put it in to
different words. Yank the barrel from your 9mm pistol
and use it to help you build functional rounds at the
"Crimp is not used to keep the bullet in place with auto
rounds, including 9mm. The resizing stage determines how
tight the bullet is held. The crimp is a "taper" crimp -
done simply to close the bell mouth made for inserting
the bullet. It should not be closed enough to see a mark
(or much of one) on the bullet if it is removed from the
case after crimping.
"The 9mm bullet must also have a short nose to seat
properly, with a preferable diameter of .355, to assure
a tight non-slipping bullet crimp; Don't deform the
bullet during the crimping process. Safety means passing
the thumb pressure test --- See Attachment 5.
"Way too much crimp. All you want to do is straighten
out the case mouth bell. Not squeeze the bullet
under-size with that much crimp!
"It's over crimped. 9mm spec is .391 at the base, and
.380~.381 at the mouth. Your .364 is too much, in fact
you can see the case bowed in at the top above the base
of the bullet. Crimping too much can actually cause the
case to bow out at the bullet base as you squeeze the
top in too much. That loosens the case tension on the
bullet. Case tension on the sides of the bullet hold it
in place, not the crimp. Too much crimp has the opposite
effect from what you would think.
"Unlike rimmed revolver rounds "crimping" is a bit of a
misnomer for pistol cartridges. You're not really
crimping into anything, just getting rid of the mouth
belling you needed to seat the bullet without shaving
"You shouldn't be "crimping". All you want to do for
crimp on 9mm is remove the flaring you did to get the
bullet seated. Crimp should be maybe 0.001" less than
bullet diameter + 2x case wall thickness.
Feedback & Comments
November 11, 2012
Message: I just started reloading, I'm using a Hornady LNL
AP,& I find when I'm reloading 9 mm luger, some rounds I can push the bullit
into the casing, should I be able to do that with my thumb? How much
pressure needs to be applied for the thumb test. Ed K.
Response - Ed, I am not familiar with your press, but I
find that I can push a bullet down into the cases BEFORE THEY ARE RESIZED by
the press but NOT AFTER resizing. That makes sense in that the cases that
you pick up from the range floor have been expanded by the firing process.
One of the first things the press does is to resize the case and push it
back down into the original correct size. I don't think there is any
criteria for your "thumb test". I assume that your bullet push test is
before the case is resized. If it is after resizing and you can still do it
I would take a closer look at your dyes and adjustments. Good luck. Tanner
April 11, 2012
You said the mouth should be .380-.381 I have some federal factory ammo and
it is .375 at the mouth that is what i was trying to match.
July 28, 2011
Subject: Reloading Data For 9mm Luger
Thanks for all the comments. Your explanation is right on. I'm not a newbie
to reloading, some 20+ years behind me. But am new to 9mm.
Just purchased a M&P9c S&W and I am about to reload my first thou. rounds.
Target only. I have been all over the net and threads of all sorts. Lots of
"junk" out there. Reloaders seem to be trying lots of things.
I want simple facts to load a Montana Gold 115gr.rn for the range. I think I
have decided on 231 powder. Win. Primers. but I can't seem to find a OAL
that is consistant among reloaders. Any professional help as to a starting
load of powder with a max. and an OAL would be appreciated. I will contact
MG for their best suggestions. I want an accuracy load not a power packin
defense load. I selected the 231 powder because I found many references to
it on the net. I want my first batch to be right on. Thanks for any and all
responses and suggestions.
Response - Wayne,
When I first started reloading, I used 4.4 gr. of Win 231 with fmj 115 gr.
round nose bullets.
My OAL was 1.150" (This was my target OAL). Plus or minus a few thousands
either way did not matter)
Min OAL was 1.095" (I stayed far away from the min.)
Max OAL was 1.163" (I stayed far away from the max.)
According to the reloading data center
(http://data.hodgdon.com/cartridge_load.asp), the Win 231 powder weight
ranges from 4.3-4.8 gr.
This formula worked fine for the few hundred rounds that I reloaded. My
friend also reloaded 9mm Luger using the same recipe with no problems. We
were shooting a Glock 17, Glock 19 and Glock 26.
Winchester 231 is a good choice for reloading 9mm Luger. All the research
that I did when I started (as well as the people at the reloading store)
indicated that Win 231 was the #1 choice. Unfortunately at that time it was
in high demand and the backorders had long waits. Instead, I decided to go
with Hodgdon Titegroup powder (it was plentiful and cheaper). I stocked up.
Turns out I made a good choice. Since then I have used only Titegroup and
have reloaded over 15,000 rounds without problems (except one squib). I now
have only one formula (for Titegroup) and I stick with it.
Winchester primers are also a good selection. I can't think of one problem
that I had with Winchester primers (except availability). If you can't get
Winchester, Wolf primers will work almost as well (since you are just
shooting targets a dud or two out of thousands can't hurt).
Tanner....thanks for your quick suggestions I greatly appreciate it. Like
your example with the 231 shortage, I was faced with no 115 gr. rn so had to
get 124 gr.plated. After research: I have found the following in various
bogs and threads. You are welcome to comment at will. I see lots of post and
speer reference book to these plated 124gr.rn bullet::: Loading for
accuracy, range, target loads: With 231 and Win. primers: starting powder
at:3.9 to 4.0
move up in tenths, 4.1,4.2,4.3 with 4.5 being the max. for that bullet.OAL
for this 124 gr rn seems to center around 1.13-1.135. I too never go to
Tanner: Just for my clarity and your info...I like
to use the word plated when using plated bullets and I like to use the term
Full Metal Jacket when it truely is. Correct me if I'm in error, but doesn't
the plated bullets come "inbetween" lead and "solid copper or
brass"bullets...so all of my math with loads tend to favor the Starting
points around or just above the lead with notes of min/max for both add
together/2 and arrive at a mid/mix for plated. Same for powder. Correct me
please on any of this. for the 124 gr. Rainer/Frontier/Berry etc. in round
nose. Thanks man I truely appreciate your helping me out on this.
Response - Wayne,
Just for info, a good place to by bullets online is
http://www.precisiondelta.com/detail.php?sku=B-9-115-FMJ. Free shipping too.
Both my friend and I purchase through them twice with no problems, and they
The only things I know about plated bullets is what I read on the Berry’s
“Plated bullets occupy a position between cast bullets and jacketed bullets.
They are soft lead, but have a hard outer shell on them. When loading plated
bullets we have found best results using low- to mid-range jacketed data in
the load manual. You must use data for a bullet that has the same weight and
profile as the one you are loading. Do not exceed mid-range loads. Do not
use magnum loads.”
I ordered once from Berry’s. The bullets were nice and pretty but were
I have never loaded 124 grain bullets so I have no suggestions regarding the
recipe. The reloading data center only shows..
It’s a shame that the reloading books never seem to have an exact recipe for
the exact combination of what you are reloading to. It involves some
educated guessing, and that is what makes trying new recipes a little scary.
Just one more thing (which I am sure you know) when you shoot your first 9mm
reloads I would start out with a fairly close target so you can see where
each bullets goes (to make sure that it came out of the barrel). You don’t
want to have a surprise squib.
Later, if you remember, let me know what you ended up with and how they
Thanks again......and yes, with workup loads I load
and shoot 1..single shot. 3 reps per work up load. Then I put 1 in chamber
from clip and one in clip. The first 3 "singles" are for safety as you
pointed out, and one single bullet coming off clip, feeling the slide travel
etc. The second rep with one in barrel and one in clip is the same with clip
feeding review added. Then I'll go to one in barrel, and 2-3 in clip. I
still shoot these very slow, but I am "feeling" the process'es take place
all the while inspecting the brass for signs of whatever.
Thanks for the WSF info. Somewhere in my notes I
have that very "chart" with WSF OAL at 1.169 and thats max length. So at the
time I questioned it and kept reading. Most manuals I have reviewed
indiciate that a 2-3 thousands away from lands and groves is desirable for
I put a "loose"bullet in a resized case and shoved
it in the barrel. This max OAL came out right on spects at 1.168-1.169. So
using the 2-3 thousands before rifeling that leaves 1.138-1.149. And I found
several post at 1.135 with various 124gr plated rn. And If I use my Speer
book....between lead and FMJ is 1.13 or 1.135 OAL. And thats with all
I have an old friend who shot in some world
competition. He makes guns. He claims on rifles that he only resized the
necks and OAL was set at (on) the rifling. Bolt actions are very well made.
Auto pistols are (in my opinion) very sloppy guns. They can be made to be
accurate, but because of ALL the functions a single bullet is master of, it
always leaves room for improvements to accuracy.
I am going to start out at: 3.9 of 231 with the
124gr at 1.135. The same for each tenth of a grain up to 4.2. Stop and
access all (at home). The max for lead is 4.1 and max for FMJ is 4.5gr.
speer book #12 page500-501.
Thanks again....I'll post and email you exactly how
it goes....if I get my wife to allow me to shoot the test rounds.....lol.
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ABOUT THE AUTHOR
Former aerospace engineer who specialized in
hypergolic propellants. Hobbies include shooting zombies & reloading