45ACP and the crimp. Most bullets are tight, a few are not. Why?


July 8, 2011, 01:33 AM
I'm confused about how much crimp I should put on my .45ACP. I'm currently using a 3 die RCBS kit (resize/deprime, bell, seat/crimp), and have been guilty of crimping the living shizzle outta the case, all the way to putting almost nothing on it and having the bullet get pushed into the case when loading into the magazine. I've improved upon my crimping, but I'm still unsure about why a small number of my cartridges have a bullet that will spin/push into the case.

Let me explain what happened last time I was reloading. Looking at my Lyman #49 reloading manual (printed in 2008), it says that the case mouth should be .473 (I think these numbers are accurate, they're from memory). To me, that means basically increase crimp until you're at that number. When loading up a few boxes on my RCBS Rock Chucker, I had 2 cartridges that would still allow me to rotate the bullet in the case. All 98 others appeared to be tight (but not too tight where plated bullet is all wrinkled at the case mouth) and ready to go, all very near .471 measurement. I know that all my cases were run through the sizing and depriming die, but I'm not sure why these fit the bullet differently. Shouldn't all cases be brought back into a valid size with resizing? Or are these cases perhaps just past their useful life? If this is the case (no pun intended!), there's nothing that can be done? Also, do I crimp to .473 or is my slightly tighter crimp no big deal? Is there some acceptable range of crimp? I'm using a Glock21 with both factory and Lone Wolf barrels. My rounds are mostly 5.7gr W231 with 200gr plated lead flat nose out of the 5" barrel. My rounds usually go BOOOM, so I'm doing enough things correctly, but am I missing something obvious? Thanks for your help!


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July 8, 2011, 01:39 AM
Are you sorting headstamps? Different headstamps have different thickness brass.

RP is notoriously thin. I only use it for .452 cast bullets.
TZZ goes right in the trash.

PMC seems to be the thickest. I use that for my XTP anti-zombie loads. ;)

Sometimes overcrimping can be bad.

Are you using a taper crimp die?

July 8, 2011, 01:51 AM
Well, I've only loaded a few thousand .45ACP rounds and I'm far from an expert.

What I believe to be true is -

1. Tension is provided by resizing and not by crimp. (Magnum revolver cartridges and slow powders can require a very heavy roll crimp to prevent bullet pull and provide proper burn, but the .45ACP doesn't fall into that category.)

2. For .45ACP the correct crimp is not much of a crimp at all, but is just the removal of the "bell" that is created by the powder-thru die (or similar die for single stage reloaders.) This is usually described as a taper crimp and the correct profile isn't much different from a straight line.

3. Theoretically, the .45ACP headspaces on the case mouth, so you don't want to "bury" the case mouth in the bullet. Many reloaders do this to some degree or another anyway, with good results, as many pistols control headspace with the extractor. However, it isn't typical practice. I believe your 0.471" diameter at the case mouth is correct.

4. Removal of the bell is most easily done by a separate taper crimp die, but it can be done (carefully) with a combination taper crimp/seater die and one operation if it is set up correctly.

5. Some cases just have thinner case walls than others. I believe Remington is the usual culprit, but I'm not sure. These can be a real problem, as the ID after resizing just may not be small enough to develop the proper tension.
(If you have only a few of these and they can be sorted out, sometimes the easiest solution is to just toss them...)

6. Bullet diameter has to be correct and consistent. Some manufacturers occasionally make a few that are undersized.

In other words, loose bullets can be caused by bad components, or bad setup, or both. Trying to track it down is kind of like a murder mystery, and can take some patience. :)

Steve in PA
July 8, 2011, 01:57 AM
I've been reloading the .45acp for several years now. After my initial set up, I have not touched my dies. I use the RCBS dies and seat/crimp in one step. I use mixed cases, (Rem, Speer, PMC, etc) and Rainier 230gr bullets. I cannot beging to tell you how many thousands of rounds I have reloaded, and have no problems like the OP.

I agree, that it is either bad bullets or bad set up of dies.

July 8, 2011, 02:08 AM
4. Removal of the bell is most easily done by a separate taper crimp die, but it can be done (carefully) with a combination taper crimp/seater die and one operation if it is set up correctly.

Is there such a thing as a taper crimp/seating die? I don't see how that would work. It certainly wouldn't for cast lead. My Lee seating die will definitely shave lead if I don't have it adjusted correctly. I get around that with the Taper Crimp. The seating die doesn't need to be so precise.

While (according to other reloaders) the taper crimp isn't 100% necessary it sure makes life a lot easier. I wouldn't be without it.

July 8, 2011, 02:29 AM
Is there such a thing as a taper crimp/seating die?

Well, I think that particular animal has been hit several times in this thread -


And here's one made by RCBS -

RCBS 45ACP Taper Crimp Seater (http://www.budsgunshop.com/catalog/product_info.php/products_id/64403)

I use a separate taper crimp die myself, but there are some who want to do this in one step even if it is problematic. (Lately, it seems to be related to the number of stations on a Hornady LNL AP... :) )

July 8, 2011, 07:46 AM
RP is notoriously thin. ........................
TZZ goes right in the trash.Yep, RP is thin, and some sizers that work fine with other brass will not size RP enough. Please send all TZZ brass to me. It is IMI brass.

Yes, there is such a thing as a .45 ACP seater crimper which uses a taper crimp. It is what reloaders used for decades to load millions of rounds of .45 ACP ammo. RCBS and Reddding still make them. Lyman too I believe.

I has become popular to crimp in a second step even in applications where it doesn't have to be. Folks posting wrongly about how hard it is to do doesn't help. Neck tension holds the bullet. All you need is a slight taper crimp. Just enough to remove the bell, or at most .002 crimp. Easy peasey. :)

July 8, 2011, 07:54 AM
After FL sizing, no expander, is the bullet tight in the case? If loose, brass wall thickness is thin, or you need a FL die that sizes more. Measure your expander, it should be .450" or slightly smaller. If larger than .450" turn it down to smaller.

July 8, 2011, 08:07 AM
As others have mentioned, look at your brass. Look at the headstamp for those rounds with a loose bullet, and those that are tight, and I bet you will see a difference.

The crimp measurement given in the manual is the max spec, not what your gun will like. A crimp of .469 - .470 seems to work for me for mixed headstamp brass, and I've used the exact load in my 1911s.

July 8, 2011, 09:28 AM
The crimp measurement given in the manual is the max spec, not what your gun will like.

Thanks gregj, that's a good point. For my Glock21 .471 loads fine, but I also have a Lone Wolf barrel being delivered and I'll need to check and see what'll work best for that.

Thanks everyone for their responses, I appreciate the info and I'll check the headstamp for the loose ones.


July 9, 2011, 03:04 AM
I think something else is afoot.

He mentioned that he's using "plated" bullets.

I've seen some plated bullets where they didn't cull the "culls" and some under plated, meaning under sized bullets got through the q-c personnel.

With most brass and my "cast" bullets, I've not seen the issue with "loose" bullets unless the bullet was defective. Even with Remington or A-merc brass. I don't use my .45's for competition so I don't segregate the brass. I've even got some mil-spec brass thats got 1918 head stamps so I expect it's rather "experienced" brass at that......

I suspect an "under plated" bullet that's not full diameter. The bullets are plated in an electro-plating tank and the bullets might not have gotten full current or proper solution and got inadequate deposition of alloy.

Aren't using "Berry" bullets by chance are you ????? Hint, hint~!!!!

July 9, 2011, 06:14 AM
I'm a little fussy when it comes to reloading or shall I say that my 1911 is a little fussy as to what it likes to be fed.

I've only been shooting and reloading for less than 5 months now.

I've already reloaded and shot over 4,000 rounds of .45 ACP.

I've never purchased a single manufactured round of .45 ACP.

I began using the Lee Deluxe Pistol Four Die Set so I was seating and crimping in separate stages but I was still getting jams on the first round of a fresh magazine quite often.

It was suggested to me to sort my brass by headstamp and not to crimp brass which didin't require it. This helped reduce the frequency of jams by 50%.

I recently switched to a Hornady LnL AP Progressive presswhich doesn't have enough stations to factory crimpso I started using a Dillon case gauge to check my rounds.

Any rounds that don't drop freely into the case gauge get run through the Lee Factory Crimp Die which has the crimp ring backed off. This allows pos sizing.

July 9, 2011, 11:23 AM
Try seating and crimping in two separate steps.

July 9, 2011, 11:49 AM
Try seating and crimping in two separate steps.

Especially important with lead or platted bullets, not so critical with jacketed.

I always remove the bell in a separate step for any bullet.

Crimp is not the main thing holding the bullet, the interference fit between the correctly sized shall and the larger bullet diameter stretches the brass to provide most of the tension.

sean eady
July 9, 2011, 03:38 PM
First post , so hello to all..... I just got into reloading and am still figuring things out myself. I also use the RCBS 3 die sets on a single stage rock chucker. I have recently had issues with my 9mm cases and was told to try seating and crimping as seperate steps and picked up a Lee Factory crimp die. To make a long story short it did indeed take care of the 9mm case issues and I immediatly purchased one for all of the pistol calibers I reload. Yes it adds 1 more step , but well worth the end result .... Try one out for your 45's very easy to adjust and gives a perfect crimp (or bell removal) by following the instructions that come with the die.

July 9, 2011, 03:48 PM
While it is true that brass from different makers has different dimensions in such as case mouth thickness and thus inside diameter it is also true that brass, even from the same lot, may be of differing elasticity or ductility. IOW, you can size it and it won't stay at the smaller diameter OR when you shoot it it is too brittle and it cracks. Annealing MIGHT help but I find that usually, when brass that was previously ok won't get a good grip on a bullet it is best to simply chuck it into the recycle can. One also has to accept that one has to use reason and logic to determine exactly what the problem is with the brass at hand.

July 9, 2011, 09:31 PM
I've only run across two cases that wouldn't hold neck tension and that was recently, almost 30 yrs. since starting to reload.
If a case is properely resized, the bullet should not be able to be moved at all without the use of a puller. Try seating the bullet without a crimp and I'll bet you can't mve the bullet at all. If that holds true then your problem is how your applying the crimp, not the brass.
This is not to say some cartridges don't need a crimp, some do because of their application. The rule of thumb is to apply the least amount of crimp necessary to prevent bullet jump. Start by measuring the OAL and shoot all but the last round, and then measure it to see if it changed OAL. If it did change increase the crimp a little bit more until you've stopped it from moving. Over crimping can actually cause you to loose neck tension by buckling or collasping the the case.

July 10, 2011, 11:35 PM
As said: The crimp doesn't retain the bullet, the sizing does.
The crimp is to remove the belling of the mouth when seating the bullet. If it feeds reliably it's good-to-go.

Lothar Allen
July 11, 2011, 03:51 AM
remember that crimp is case length dependent.

July 11, 2011, 03:55 AM
I've found a separate taper crimp die is fairly tolerant of variations in case length.

After all, it is just removing the bell, not trying to "roll over" the case mouth a precise amount.

July 11, 2011, 07:33 AM
Yep, a proper taper crimp is very tolerant of case length, and, as posted, we are using very little "crimp".

July 11, 2011, 07:56 AM
TZZ goes right in the trash.

I found them decent. In fact, just loaded up two hundred for a xsteel match with no problems. Now if you're talking Americ, thet isn't worth the effort to throw out.

July 11, 2011, 01:19 PM
I stil have over 10,000 TZ & TZZ .45 ACP shells, some on their 10th loading.

There is nothing wrong with them.

Both head stamps are Israeli Military Industries (IMI).

July 14, 2011, 12:27 AM
Got my rockchucker setup today (finally) and started playing with the 45ACP dies. I don't have my caliper yet, it's on back-order, I may just run down to Lowes tomorrow and get one if I get impatient. Anyways, when I got to the crimp/seat step I set up my die off of a loaded federal round and popped out a couple of blanks. When I get the caliper then I can check them for OAL and start putting powder and primers in, but I want the rest of the round set up propperly before I start making them hot. I've been very nervous about the crimp step and wondering if it's maybe too tight, too loose, etc. I can see a very slight necking on them, maybe only the last 1/16-1/8 of an inch, but the bullets are not moving with force applied. How important is crimp? I mean, my XD isn't going to blow up if they are a shade tight is it? Not too worried about them being loose at the moment, they've got plenty of tension.

Added this here cause it's related and I didn't want to start a similar thread.

July 14, 2011, 02:00 AM
I've been very nervous about the crimp step and wondering if it's maybe too tight, too loose, etc. I can see a very slight necking on them, maybe only the last 1/16-1/8 of an inch, but the bullets are not moving with force applied. How important is crimp?...

See post #18.

July 14, 2011, 07:44 AM
If you see "necking" on your .45 ACP rounds, you are over crimping. You only need enough to remove the bell or a hair more. Neck tension holds the bullet in .45 ACP. No amount of crimp can fix poor neck tension.


Master Blaster
July 14, 2011, 02:56 PM
Try belling the case mouth less, too much belling is what causes poor case tension in .45 acp.

As far as RP brass being thin I never had a problem, and about half the 100,000 or so .45 acp rounds I have loaded have been with RP brass, I have some batches of brass that have 14 reloadings on them with no problems.

July 14, 2011, 10:34 PM
Okay, so I'll try to bell them less. That being said, I thought I was doing almost zero to begin, but that's gotta be wrong. I'll give that a try and we'll see what happens.

I have a new problem but I think I need to start a new thread. Recently bought a Lone Wolf barrel and can't seem to get my cartridges to fit correctly.. http://www.thehighroad.org/showthread.php?p=7442650#post7442650. If you get a chance maybe check it out and offer a suggestion? Again, thanks for the time!

July 17, 2011, 03:17 PM
If you were belling minimally before, don't deviate. Not enough bell can shave lead or copper when seating bullets.

I use .473" in my guns which is pretty much just a straightening out of the case mouth. I beliebe your LW chamber is bad and that's why you are struggling.

July 17, 2011, 03:34 PM
Please send all TZZ brass to me.

I'll take whatever Anthony doesn't have room to store.

I've used thousands since the mid-80s. I lose it before it splits.

July 17, 2011, 06:10 PM
I decided to add some more belling to my cases on my most recent box. What I noticed is that my bullets do fit easier due to the fact that there's less tension going in and the plating stays intact. I also started doing a 2 pull seating/crimp stage (still using the single seating/crimp die). This means that I pull the handle only part way the first time to start the seat of the bullet, then I drive it home on a second pull. Also, I've been much more careful about aligning/centering the bullet in the case before anything. This way there's no more tension on one side than another as it's getting pushed into the case. A very high percentage of my rounds looks better and also fit into my Lone Wolf barrel better. Still, I did have 2 rounds that had the bullet just fall into. These must have missed sizing or something because when I ran them through the sizer, all was then fine. That being said, I have no idea how these got missed. User error.

I'll use any .45 brass that's got a large pistol primer pocket.

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