9mm Overpressure Due to Crimping Too Tight?

[DonMountain]

I have been working on reloading some 9mm Luger ammo lately, and have been having trouble with high pressure signs in the primer even when using starting loads of W-231 or Bullseye powder. Now I am thinking that maybe I am crimping with a taper crimp die too tightly. Is this a problem with these small, high pressure pistol cartridges? I have tried jacketed and powder coated lead projectiles.

[Pawpaw757]

I think we need a little more info. How much powder, OAL, things like that.

[wv109323]

I wold think that is not your problem. What pressure signs are you seeing? Are you suse your powder measuring/weighing is correct?
Taper crimp a jacketed bullet. Then pull the bullet and look for distortion in the jacket. If the bullet is distorted you are crimping too much.
Also if cast are over crimped you may loose accuracy. How due they shoot?

[wv109323]

I wold think that is not your problem. What pressure signs are you seeing? Are you suse your powder measuring/weighing is correct?
Taper crimp a jacketed bullet. Then pull the bullet and look for distortion in the jacket. If the bullet is distorted you are crimping too much.
Also if cast are over crimped you may loose accuracy. How due they shoot?

[lefty o]

you really dont need a "crimp". set the die to straighten the bell back out of the case after seating a bullet. that will almost surely give enough neck tension to hold the bullet fine.

[35remington]

Taper crimping does not secure the bullet in such a way that it “causes” high pressure.

“High pressure signs in the primer” are notoriously unreliable. If the chronograph shows acceptable velocities you are not experiencing unacceptable pressures.

The real problem is that you are placing faith in information that likely means nothing and contradicts what is known. Get better information that actually tells you something. Tell us something more relevant about loading particulars. Then get back to us.

[Kestrel4k]

Could be anything; perhaps an undersized firing pin or related issue causing extrusion (& even shearing) of the primer cup - have seen tons of once-fired brass exhibiting this. Really depends on what 'pressure signs' you're seeing ?

[tazman]

I have been working on reloading some 9mm Luger ammo lately, and have been having trouble with high pressure signs in the primer even when using starting loads of W-231 or Bullseye powder. Now I am thinking that maybe I am crimping with a taper crimp die too tightly. Is this a problem with these small, high pressure pistol cartridges? I have tried jacketed and powder coated lead projectiles.

A couple of years ago I got a batch of primers that showed high pressure signs and even had pierced primers part of the time with loads I had been shooting for years. It turned out to be a bad batch of primers. I switched primer brands and the problem disappeared immediately.

[376Steyr]

To the OP: Does factory ammo show the same symptoms? If it does, you have a gun problem, not an ammo problem.

[DonMountain]

Taper crimping does not secure the bullet in such a way that it “causes” high pressure.

“High pressure signs in the primer” are notoriously unreliable. If the chronograph shows acceptable velocities you are not experiencing unacceptable pressures.

The real problem is that you are placing faith in information that likely means nothing and contradicts what is known. Get better information that actually tells you something. Tell us something more relevant about loading particulars. Then get back to us.

I guess this pretty much covers everything then. And I appreciate all of the help from you-guys. I will just ignore the flattened, cratered primers and the occasional stove-pipe in the chamber from loadings of powder that are at the bottom of the list in the books. The Hornady and Lyman Cast Bullet Manuals are obviously in error, so I will just ignore them too as being probably wrong. I have tried three different pistol primers and one small rifle primer and they all produce the same results. But factory Winchester rounds I bought from WalMart shoot just fine and have none of these signs. No flattened primers or problems ejecting. So, its not a gun issue as it is a brand new gun. Not a problem until I reload these same cases. But I guess I am just looking at it from a bad perspective and just need to ignore what I thought was a problem. As I said before, thanks for all of your help in working out this issue.

[str8wal]

The crimp is not the issue. Have you tried any other loads that are not at minimum?

[glockfan]

why don't you post the load you use: boolit weight,powder type and charge , COAL....this way an accurate opinion can be exposed.

[Ramguy]

I use 3.5 gr of BE with pretty good results in my Glocks. That's with both cast and jacketed. I will admit that in my younger days I was more liberal with the powder, and I see that some say primer signs are not a big deal, but they were to me. I liked my guns and my digits so I backed off. no more major 9 for me.....

[xrayfk05]

I will just ignore the flattened, cratered primers and the occasional stove-pipe in the chamber from loadings of powder that are at the bottom of the list in the books. The Hornady and Lyman Cast Bullet Manuals are obviously in error, so I will just ignore them too as being probably wrong.


I am not sure if it is meant that way, but your reply sounds pretty offensive to me.

No one said you should ignore flattened/cratered primers but primer signs are hard to impossible to read, not only do they differ between brands but also between guns. So far you have given us very little information to go on, post some pictures or load data maybe?
Stove pipes are a typical symptom of under-powered loads, up your charge a bit and the problem will go away. Whatever you are seeing on your primers are not overpressure signs if you also get stove pipes.

A primer does not know it in what cartridge it is fired, and what the max. pressure is. How would this be a reliable indicator?

[roysha]

A thought that may be a bit far out but here goes. Is it possible that you are putting so much crimp on that you are actually reducing the mouth diameter enough so you are losing your headspace? This would cause the FP to drive the case forward into the barrel a bit till either the case finally stopped at the throat or, more likely, the extractor stops the forward movement of the case in the chamber. This would cause the primer to back out a bit upon firing and then as the pressure builds the case would move back against the breech face causing the flattened appearance of the primer.

I have seen this many times with rifle reloads when the reloader did not adjust the sizer die properly. I don't know whether it can happen with a pistol or not but would be inclined to think it could.

Regarding the post that said no crimp was required, I DISAGREE totally! Although it doesn't take much of a crimp, anything to keep the bullet from moving into the case while transitioning from the magazine to the chamber is important.

Just a personal thing, but I hate 231. If it was the only powder available to me, I believe I would quit shooting pistol altogether.

[rototerrier]

I guess this pretty much covers everything then. And I appreciate all of the help from you-guys. I will just ignore the flattened, cratered primers and the occasional stove-pipe in the chamber from loadings of powder that are at the bottom of the list in the books. The Hornady and Lyman Cast Bullet Manuals are obviously in error, so I will just ignore them too as being probably wrong. I have tried three different pistol primers and one small rifle primer and they all produce the same results. But factory Winchester rounds I bought from WalMart shoot just fine and have none of these signs. No flattened primers or problems ejecting. So, its not a gun issue as it is a brand new gun. Not a problem until I reload these same cases. But I guess I am just looking at it from a bad perspective and just need to ignore what I thought was a problem. As I said before, thanks for all of your help in working out this issue.

Without the load and specs, everyone is just guessing.

I could almost guarantee everyone here has loaded for your bullet weight and with the powder you've listed. I know I have. But I'm not going to speculate until you give the specs of the load. You are getting attitude with folks trying to help and are not giving us the proper information to do so.

Something seems strange here.

[6bg6ga]

Please provide load data. Powder and load/grains, Bullet weight and type.

[Lloyd Smale]

never seen crimp cause excessive pressures. Powder charge and seating depth cause 99 percent of high pressure problems.

[trapper9260]

Data is a guide,lower you powder and see what you got. Like stated need more info on it all.Work with the powder otherwise.

[contender1]

"never seen crimp cause excessive pressures. Powder charge and seating depth cause 99 percent of high pressure problems. "

^^^^^THIS^^^^

9mm is a very depth sensitive caliber. You mentioned using a taper crimp,, as it should be. But OAL combined with the types of powder,,, can be the issue. Win 231 & Bullseye are both fast burning powders. My GUESS would point heavily to a bullet seated too deep.
You have mentioned those 2 powders, and different primers, along with the crimp. The one thing I do not see you have tried is a different seating depth. Even .010 can make a big difference.

[saleen322]

One more vote for seating depth. 9mms particularly spike in pressure if they are seated too deep. Use the same load but set the OAL to maximum. You will likely see a reduction in pressure indications.

[reddog81]

The Hornady and Lyman Cast Bullet Manuals are obviously in error, so I will just ignore them too as being probably wrong.

Where is the Hornady and Lyman manual does it say that the taper crimp on 9mm can cause pressure issues?

[44MAG#1]

Where is the Hornady and Lyman manual does it say that the taper crimp on 9mm can cause pressure issues?

They dont say that . He is just upset that he didnt get the answer that he wanted. We have all been that way at sometime or another.
I have come to ignore long ago primer sign as a method to predict pressure as most have. I AM NOT SAYING it is not possible. Just that it is an UNRELIABLE way.
The OP wanted answers that validated his opinion and when he didnt get them he was upset.

[Dusty Bannister]

Even though the appearance of the primers may be unreliable to show pressure signs, it would show that something is different and then it would be up to the individual to seek out the cause. This could be a learning experience for others, or maybe the OP found his mistake and thought that was good enough. Some of the newer cases have oversized flash holes, some cases have the reinforced sides in the web area, and it is possible that some unknown debris got accidentally left in the case. That is of course just operator error. On the other hand, Cartridge OAL is also very likely part of the problem. There were a lot of suggestions and unfortunately ignoring the primer appearance is not really what was intended by that comment.

Perhaps the OP is just taking time to work through the suggestions in an orderly manner and will update when the problem has been discovered. SWMBO might have other priorities and keeping things happy in the home is likely more important than updating a thread. Dusty

[44MAG#1]

Even though the appearance of the primers may be unreliable to show pressure signs, it would show that something is different and then it would be up to the individual to seek out the cause. This could be a learning experience for others, or maybe the OP found his mistake and thought that was good enough. Some of the newer cases have oversized flash holes, some cases have the reinforced sides in the web area, and it is possible that some unknown debris got accidentally left in the case. That is of course just operator error. On the other hand, Cartridge OAL is also very likely part of the problem. There were a lot of suggestions and unfortunately ignoring the primer appearance is not really what was intended by that comment.

Perhaps the OP is just taking time to work through the suggestions in an orderly manner and will update when the problem has been discovered. SWMBO might have other priorities and keeping things happy in the home is likely more important than updating a thread. Dusty

While you may be correct I choose to look at human nature. He never gave much info. Why? Like getting a doctor to diagnose a disease over the phone by telling him your sneezing a lot and taking aspirin but its not helping.
What is wrong with me doc? Prescribe me some meds.

[Soundguy]

you really dont need a "crimp". set the die to straighten the bell back out of the case after seating a bullet. that will almost surely give enough neck tension to hold the bullet fine.

You are muddying the water.

All the manuals call debelling a taper cartridge a taper crimp. ( vs roll crimp, etc. )

Telling someone they don't need to crimp is counter productive, and blows the newbies minds that are reading and not posting.

It should be fully understood by anyone that has been reloading for any significant amount of time that a taper crimp is reforming the brass to close the bell and provide neck tension on the projectile, vs something like the taper crimp that actually is rolling an edge over.. ( you could argue that's not a crimp too ), or vs a factory crimp that uses some fingers at the mouth to press inward.

I cringe every time I hear someone tell someone not to crimp a (taper) crimp cartridge... because the person you are telling it to usually has low experience, and might not understand that YES, it does need a trip thru the crimp die..

All the major manufacturers are calling the die a crimp die, and the manuals call it a taper crimp.

to do anything else is just confusing the newbies.

[Soundguy]

Did he say anywhere what primer pressure signs he was seeing? flatenned? popping out?

If he's on the low end and gettign primers unseating, he may simply be too low.

[44MAG#1]

You can use a roll crimp die to straighten out the flare hence "taper" crimping. But a taper crimp die cannot roll crimp. Besides all the taper crimp dies ive seen says taper crimp on them.

[Texas by God]

Some of us are old enough to remember no such thing as a taper crimp die. For auto pistol cartridges that headspace on the case mouth the seating die squeezed the bell back to paralell. But as soon as I discovered the taper crimp die I got one in .45 ACP. Because they help.

Sent from my SAMSUNG-SM-G930A using Tapatalk

[Neverhome]

I've had "pressure signs" on primers when no excess pressure was there from too much headspace. And also from gun oil in the chamber and/or on the case.

[redhawk0]

I remember in my early reloading days, I cast some 208gr WCs for my 44Mag. I was only loading for target shooting and the Lee 208gr did the trick....however, I found no loading data for that particular bullet design so I was...shall we say....winging it. I found loading data for a 220 or 225gr bullet (I forget now...30 years ago) and loaded to the low end for the powder weight listed for W-231. I had severely flattened primers, and some punctures.

I started making some inquiries on the old castpic site and found out it was due to my seating depth. Since the entire boollit, except for the last 0.1", was pushed into the case (unlike the 240gr RN I was used to shooting)...the pressure was way too high for what I was trying to accomplish.

Anyway...to make a long story short...I cut my powder back to 60% of those initial loads and they shot great, no primer flattening, no piercings...just a whole lot of fun at the range.

So....without more information...I vote for seating depth as the culprit as well.

redhawk

[lefty o]

You are muddying the water.

All the manuals call debelling a taper cartridge a taper crimp. ( vs roll crimp, etc. )

Telling someone they don't need to crimp is counter productive, and blows the newbies minds that are reading and not posting.

It should be fully understood by anyone that has been reloading for any significant amount of time that a taper crimp is reforming the brass to close the bell and provide neck tension on the projectile, vs something like the taper crimp that actually is rolling an edge over.. ( you could argue that's not a crimp too ), or vs a factory crimp that uses some fingers at the mouth to press inward.

I cringe every time I hear someone tell someone not to crimp a (taper) crimp cartridge... because the person you are telling it to usually has low experience, and might not understand that YES, it does need a trip thru the crimp die..

All the major manufacturers are calling the die a crimp die, and the manuals call it a taper crimp.

to do anything else is just confusing the newbies.

settle down, i am not muddying anything. many people put way too much crimp on their cartridges, and it causes many problems. removing the bell puts sufficient neck tension on the bullet, and that is all that is generally needed. yes it needs to go thru the crimp die, but it really is not crimped.

[Grmps]

IF you were over crimping a 9MM,
you would get leading to beat the band cause you'd be downsizing the boolit
If you are getting bad leading you might be over crimping
if no leading I would have to go with seating to deep or to much / hot powder

[6bg6ga]

Ok,

You do need crimp but just enough so that the bullet will not move if you place the nose of the bullet to the bench and push the case. I use my vernier caliper and measure OAL and then push on the case trying to see if the bullet will move in the case. I then re-measure the OAL of the round and see if there has been any change. If it moves then simply adjust slightly to obtain more tension.

With respect the the OAL in the manuals..... I set up my length and then place the bullet/round in the barrel once the barrel has been taken out of the gun. The case needs to be even with the back of the barrel. If the case sticks out past then its too long and if its in too far its too short.

Never seen a 9mm blown sky high but I have seen 40 cals that went to meet their maker.

Pay attention to the load!!! Go according to the manual unless you have 50 or 60 years of reloading and really know what your doing developing a load from scratch. Always drop a load into a case and dump it into the scale pan and weigh it to see if your actually getting what you want in the load. I suggest that you weight about 10 or so to start and see if the load varies any. Once this is done and the load is indeed true then weight about every 50 or so. If using a powder dropper like RCBS and such use the same method each time otherwise the charge will vary.

[Mr_Sheesh]

I know I'd sure like to see the loaded rounds plunked into the barrel to see if the crimp is excessive, some pics of the fired primers & loaded rounds, in general more info, before I have enough data to have a solid opinion; Till then we're doing intelligent guesstimation, which might help get them to the answer but may not be "THE" answer.

And I can understand the OP being a little upset at being told to ignore the hot primer signs etc. - I know if it were me I'd feel a few DOZEN twinges of paranoia, for good reason, at that point! I like my face the way it is, TYVM, don't want to need plastic surgery on it from pieces of a firearm slamming into it, and excessive pressures make me consider that a real possibility... Me no like!

[Forrest r]

9mm's are always interesting when it comes to reloaders and what so view as ok, not good, what to do, etc.

https://i.imgur.com/iVohJkW.png

https://i.imgur.com/UlcjxB5.jpg

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

[6bg6ga]

My OAL for a 9mm with X-Treme 124gr hollow point plated bullet is 1.083

216378

216379

[6bg6ga]

I don't believe I have adopted the so called plunk test. I simply put the round into the barrel and adjust OAL until the rim end is even like shown in the picture. Too shallow and there is going to be additional pressure. To long and your not going to get what I refer to as lock up.

[6bg6ga]

After getting the length correct I then check to see if the rounds will load into the magazine. Never had a situation where the OAL was correct and the rounds wouldn't work in the magazine. Now, I haven't gone into too much detail with my explanation of OAL and crimp. What I have shown in the two pictures has always worked for me and generally is a little more length than what is possibly shown in some of the manuals.

Obtaining just enough crimp is easy as I have mentioned. Just enough so the bullet won't move and your set and this is checked with either a vernier or a micrometer.

Length as the picture shows the rear of the shell casing is flush with the end of the barrel as shown in the picture.

I used to worry about the pressure. The 9mm round seems to have a tendency to flatten the primers more than some other rounds. I have been told by those in the know here not to worry about a primer that has flattened so I guess take out a quarter and flip the coin and settle on the answer you get.

Anyway, you have my answers for what has worked for me for years. I've never blown up a gun so either I am very lucky or I might know what I am doing. Take your pick on the answer.

[xrayfk05]

Ok,
You do need crimp but just enough so that the bullet will not move if you place the nose of the bullet to the bench and push the case.

A taper crimp does not hold the bullet in place, that is done by the case neck tension caused by the sizing.
If you can push in a bullet by hand you sizing die is out of spec or not setup correctly.

[6bg6ga]

Taper Crimping. Unlike a roll crimp, a taper crimp does not leave a radiused edge on the case mouth. A taper crimp simply flattens out the 'belling' that was previously done by the expander die, and squeezes the case mouth tightly against (but still mostly parallel to) the sides of the bullet.

So yes it does put tension on the bullet. Try simply loading one round without crimping and see what happens. The bullet will move. Now put the bullet into the loader again and do a crimp and remove it. The bullet will no longer move if the crimp is correct.

The Full length sizing die sizes the whole case back to spec. Once this is done the primer is expelled and a new primer can be installed. Once this has been acomplished the neck of the case is belled and powder is put in. From there a bullet is seated in the case and from there the the crimp die removes the belled case neck and crimps the bullet.

This is the correct explanation.

[winelover]

Ok,

You do need crimp but just enough so that the bullet will not move if you place the nose of the bullet to the bench and push the case. I use my vernier caliper and measure OAL and then push on the case trying to see if the bullet will move in the case. I then re-measure the OAL of the round and see if there has been any change. If it moves then simply adjust slightly to obtain more tension.

With respect the the OAL in the manuals..... I set up my length and then place the bullet/round in the barrel once the barrel has been taken out of the gun. The case needs to be even with the back of the barrel. If the case sticks out past then its too long and if its in too far its too short.

Never seen a 9mm blown sky high but I have seen 40 cals that went to meet their maker.

Pay attention to the load!!! Go according to the manual unless you have 50 or 60 years of reloading and really know what your doing developing a load from scratch. Always drop a load into a case and dump it into the scale pan and weigh it to see if your actually getting what you want in the load. I suggest that you weight about 10 or so to start and see if the load varies any. Once this is done and the load is indeed true then weight about every 50 or so. If using a powder dropper like RCBS and such use the same method each time otherwise the charge will vary.

Bingo.........

Winelover

[contender1]

Well, I see the OP hasn't responded to all the additional information posted here.

[44MAG#1]

Well, I see the OP hasn't responded to all the additional information posted here.

Does that surprize you? He either got upset over the responses not comfirming what he thought he knew or he was just bored.

[Soundguy]

unfortunate to see questions asked, then never revisited.

[Soundguy]

settle down, i am not muddying anything. many people put way too much crimp on their cartridges, and it causes many problems. removing the bell puts sufficient neck tension on the bullet, and that is all that is generally needed. yes it needs to go thru the crimp die, but it really is not crimped.

it's a terminology issue that seems to trip too many people up.

[lefty o]

it's a terminology issue that seems to trip too many people up.

i guess, but my point remains...many people way over crimp. straightening the case puts plenty of tension on the bullet without actually crimping(bending the mouth of the case inward, actually indenting the brass into the bullet).

[Soundguy]

i guess, but my point remains...many people way over crimp. straightening the case puts plenty of tension on the bullet without actually crimping(bending the mouth of the case inward, actually indenting the brass into the bullet).

it's my opinion that people that started on rimmed cartridges, and didn't actually read a manual, and just reloaded as taught by 'dad' or the 'neighbor', and then they eventually transitioned into rimless cartridges, and they carried over the 'heavy crimp' they used on their magnum wheelguns.

[roysha]

A taper crimp does not hold the bullet in place, that is done by the case neck tension caused by the sizing.
If you can push in a bullet by hand you sizing die is out of spec or not setup correctly.

Reading authoritative statements like this remind me of an old biker saying, " there are two kinds of riders, those that have laid a bike down and those that will". To relate it to the shooting world, "for those that don't crimp, there are two kinds of shooters, those that have had a KABOOM and those that will". I have instances where, while trying to feed a FACTORY round with a huge HP, the gun jammed, failure to feed, and the bullet had shifted. Therefore, I ALWAYS crimp , albeit, a very small amount but a crimp into the bullet nevertheless. That's just me. If one chooses not to crimp, well supposedly we are all big boys here and can make our own decisions.


As far as the OPs none response, if I were on the receiving end of some of the smart "donkeyed" comments, I would not respond either. Some folks here have such a great insight into the human mind, they should team up with Uri Geller and take their show on the road.

[44MAG#1]

Reading authoritative statements like this remind me of an old biker saying, " there are two kinds of riders, those that have laid a bike down and those that will". To relate it to the shooting world, "for those that don't crimp, there are two kinds of shooters, those that have had a KABOOM and those that will". I have instances where, while trying to feed a FACTORY round with a huge HP, the gun jammed, failure to feed, and the bullet had shifted. Therefore, I ALWAYS crimp , albeit, a very small amount but a crimp into the bullet nevertheless. That's just me. If one chooses not to crimp, well supposedly we are all big boys here and can make our own decisions.


As far as the OPs none response, if I were on the receiving end of some of the smart "donkeyed" comments, I would not respond either. Some folks here have such a great insight into the human mind, they should team up with Uri Geller and take their show on the road.

Many people want to feel good about their ideas. They ask someone about their idea to get that feel good feeling and when someone doesnt agree with them they get hurt.
Study of humans is interesting.
Concerning crimp. I crimp jacketed and cast heavier than most when it comes to Semi Autos.

[lefty o]

it's my opinion that people that started on rimmed cartridges, and didn't actually read a manual, and just reloaded as taught by 'dad' or the 'neighbor', and then they eventually transitioned into rimless cartridges, and they carried over the 'heavy crimp' they used on their magnum wheelguns.

dont doubt any of that. see way too many people on the internet asking questions that are answered in every single reloading manual printed. those people cant be helped, as they dont want to help themselves. the rest of us can discuss things though.

[Soundguy]

Agreed. I see way too many new reloaders that haven't read a manual, don't own a manual, and get their data online from non official sources, don't work up loads, use others pet loads, etc.

Its a wonder there aren't more kabooms.

Of courst it does explain the broken pieces of guns and stocks I have seen at the range over the years, and the blown out cases where a smaller cartridge was held by the extractor claw then fired in a larger chamber and letting it partially bliw out and fire form the case.

[35remington]

He did appear to ask a question to be solved and when his disagnosis of high pressure was questioned and he was asked to provide loading information specifics he got miffed.

It is true that taper crimping is no substitute whatsoever for proper case tension. It adds nothing to jacketed bullet grip, but may help with lead bullet retention IF it is applied to greater degree than most are willing to apply it.

Said by a guy who has tested that and makes statements based on his findings.

[IllinoisCoyoteHunter]

A taper crimp does not add any tension on the bullet. It merely removes the bell put on the case to accept the bullet. Think about it... brass has spring back. Lead does not spring back. You get all the bullet tension from the sizing operation. This is one reason the manuals say to put just enough bell on the case mouth to get the base of the bullet started. No more, no less. I have tested round right out of the seating die (and before the taper crimp die) with the "push-against-the-edge-of-your-bench test" and they always pass with no setback. Try it.

[shortfal]

Saw mention of 9MM headspace here. Was looking for go/nogo dimensions for 9MM. Did not find so far. One loading manual I have state .750 CASE LENGTH for 9MM and another says .754. That said, I do not own a 9MM case that measures even .750 and I have a bunch. Some only a bit over .740. So say the go dimension is .754??? I'd bet some chambers are well deeper than that. Shoot a .745 case and expect a problem? I think not as I'm obviously doing it and have no problems at all.
Have to think the extractor is holding the cases close enough to the breech face to where actual headspace means little. Otherwise a situation could happen to where the firing pin might not reach out far enough to fire the ctg.
Interested to hear what others here think or have experienced.
Re crimping. I seat bullets without crimping then use a second die in the last station of the Dillon to just roll in the remnant of the flair. The size die reforms the case enough t get good bullet pull.
Pete

[6bg6ga]

He did appear to ask a question to be solved and when his disagnosis of high pressure was questioned and he was asked to provide loading information specifics he got miffed.

It is true that taper crimping is no substitute whatsoever for proper case tension. It adds nothing to jacketed bullet grip, but may help with lead bullet retention IF it is applied to greater degree than most are willing to apply it.

Said by a guy who has tested that and makes statements based on his findings.

I'll have to diisagree that taper crimping does nothing for case tension. Sure you FL resize your case and then you bell the case so it will aid in installation of the bullet. Once the bullet is installed to the correct depth/OAL the case will need to have that belling removed. Sure you can remove the belling so the case is absolutely straight but I suggest that you measure the case OAL and then push on the bullet and see what happens. The bullet WILL move slightly. Add MORE tension as a result of slightly more taper crimp and the bullet will be held and will not move. If you think taper crimp does nothing then crank it down more and then use your bullet puller and see what the excessive use of the taper crimp has done to the bullet. Now you have made a ring all the way around the bullet. So, yes the taper crimp does help apply enough tension to keep the bullet from moving.

[6bg6ga]

I suggest that those that don't understand how taper crimping works to read post #41.

Taper Crimping. Unlike a roll crimp, a taper crimp does not leave a radiused edge on the case mouth. A taper crimp simply flattens out the 'belling' that was previously done by the expander die, and squeezes the case mouth tightly against (but still mostly parallel to) the sides of the bullet.

Read the part where is says "squeezes the case mouth tightly against." If you still think it does nothing I suggest that you try moving the bullet prior to taper crimping it. It will move. Now, taper crimp it and it will not move. Taper crimp it too much and you WILL put excessive fore on it and you most certainly indent a ring around the bullet. So, if you think the taper crimp does nothing I suggest that you try the above and you WILL find that taper crimping DOES put pressure/tension on the bullet.

[winelover]

A taper crimp does not add any tension on the bullet. It merely removes the bell put on the case to accept the bullet. Think about it... brass has spring back. Lead does not spring back. You get all the bullet tension from the sizing operation. This is one reason the manuals say to put just enough bell on the case mouth to get the base of the bullet started. No more, no less. I have tested round right out of the seating die (and before the taper crimp die) with the "push-against-the-edge-of-your-bench test" and they always pass with no setback. Try it.


Well I don't agree and have experienced this more than thirty five years ago. I use to purchase Speer Lawman Ammunition (125 JSP) for my Browning HP. That was the original source for the Speer 9 mm brass that I would reload with their 125 gr JSP's. My dies were and still are RCBS carbide. They came without their taper crimp die............which I purchased later. After numerous loadings, my reloads weren't passing the edge of the bench test, any longer. Until, I tried their newly released taper crimp die. Brass was literally given a new lease on life. Been using that die ever since, in a separate operation. I currently load for six different nines. BTW, 9 mm was the second cartridge I learned to reload, without anyone's mentoring. The first set of dies were 38/357 RCBS steel..................I learned about the advantages of carbide, after those.

Winelover

[6bg6ga]

My experience is like yours. I have 50 years reloading and I started out with 38/357 as my first caliber to reload. I then graduated to 45acp. my first 38/357 dies employed the roll crimp that simply rolls the edge of the case into the ring on the bullet. When I started reloading jacketed bullets I found a need to have a better crimp as the roll is worthless on jacketed. i then purchased the carbide dies and an optional tapper crimp die.

I will attempt to over crimp a 9mm bullet and post a picture for those that are either unwilling to accept the fact that taper crimping DOES apply pressure to either a lead or JACKETED OR PLATED bullet. If you still cannot understand it or grasp the concept there is no hope for you in my opinion.

[6bg6ga]

216427

Note the ring on the 9mm bullet. This is a result of too much crimp and as a result the pressure tended to push into the wall of the bullet. This ought to be enough proof that the taper crimp does exert holding pressure on the bullet.

Where is that brass spring back now?

[35remington]

Take an unsized case. Put Dacron fluff in it to support the bullet in the case at the right overall length.

Taper crimp it to your desired dimension. Tap the bullet firmly against the bench. Watch the bullet move.

Jacket material is hard enough that the taper crimp does not form a sharp edged abutment for the case mouth, and the bullet still moves.

Don’t look at the ring in the jacket and posit it does something by looking at it. Actually test the effect of the taper crimp itself by doing what I have suggested and then try to tell me about how effective it is. Fee free to try varying amounts of crimp.

[6bg6ga]

Take an unsized case. Put Dacron fluff in it to support the bullet in the case at the right overall length.

Taper crimp it to your desired dimension. Tap the bullet firmly against the bench. Watch the bullet move.

Jacket material is hard enough that the taper crimp does not form a sharp edged abutment for the case mouth, and the bullet still moves.

DonÂ’t look at the ring in the jacket and posit it does something by looking at it. Actually test the effect of the taper crimp itself by doing what I have suggested and then try to tell me about how effective it is. Fee free to try varying amounts of crimp.

Why would I want to use a unsized case? That makes absolutely no sense. When you reload you do not reload unsized cases. Friend, I have been reloading 50 years now. Every single time I reload I test for any bullet movement after seating the bullet and I ALWAYS get some movement. I then taper crimp just enough to remove the flair and check for bullet movement and I always have to adjust and apply more taper crimp and this DOES stop any further bullet movement. Now, i realize what your next thought is going to be and that is your going to say that my FL sizing die is worn out. Well also tried this with band spanking new Dillon and RCBS dies...same thing. New brass with new dies...same thing.

Now, I'm not going to make a believer out of you because you cannot seem to understand. I suggest that you try the following ..load some 40 cal loads fill the mag after checking OAL on all of the rounds. Now shoot one and unload the magazine and check the OAL on all the rest. Guess what? They just changed and if you had continued to fire them off the possible result would have been some rounds where the bullet had backed into the case and resulted in excessive pressure. Friend I've seen this in person and I have witnessed a 40 blow up as a result of this. I like I said realize that you cannot accept this so I wish you the best of luck and hope as a result of your unwillingness to understand this that you do not blow up a prized firearm.

By the way take a look at the 9mm bullet that has been over crimped and tell me that you cannot change the diameter of the case. It would appear that I have done so. Note the contact point on the bullet.

[35remington]

To determine the effect of crimping alone. Remind yourself the case mouth is the same diameter as the sized case if enough crimp is applied. We are talking about the ability of the crimp alone to hold, are we not? Why not test it alone?

This separates the effect of the crimp from the holding effect of sizing. If the “ring” works as you claim this test should be performed to see if it indeed does. Pull many factory bullets and note they do not have an embedded crimp ring. They rely on tension as the primary factor as do I.

My bullets do not move when no taper crimp is applied. This is a simple function of correct sizing die diameter and expander diameter. When using Lee dies in my 45 ACP, the bullets move. A switch to correct RCBS dies fixed that. Proper loading procedure is to find dies that apply enough frictional force. Since my experience is like that of most others I discuss this with I cannot explain why you have difficulty. What you experience does not seem to be the common situation.

All I can ask you to do is try it. I have been reloading awhile myself. Ironically so doing makes the bullet hard to remove from the case but not at all hard to push in.

[35remington]

Keep in mind I am speaking only of conventionally jacketed bullets, not lead ones or thin plated ones. Your typical true FMJ, for instance.

I could and did apply a vicious taper crimp in my not tight enough dies. Bullets still moved. No amount of taper crimp on a jacketed bullet of the above description is the proper solution for dies that do not apply enough sizing or have an improper expander.....in my very considerable experience, I will add.

I have not blown up anything as a result of my practices. Probably because I am aware of what is working. If your bullets are in danger of receding into the case simply from gently bouncing around in the magazine your frictional fit is loose. The inertial forces applied to the bullets from being fired in what is really a low recoiling pistol while residing in the magazine are really modest.

Yep, have an M and P 40. Shield 40 too, which is a lot snappier.

Incidentally, have tried your “test” a number of times in both guns by shooting part of a magazine, then topping it off, shoot part of a magazine, and repeat. This was not done on purpose but mostly to have a fully loaded pistol when taking shots of opportunity when walking about or plinking. The bottom rounds in the magazine were exposed to repeated firing and moving about. None telescoped as you predict. I’m okay.

[44MAG#1]

One thing all of you can say in a positive way is Mr. Mountain has proven by his post that every Harry, Dick and Tom will believe what they want and load their ammo the way they want to.
The human mind is an awesome thing. Right, wrong and indifferent all wrapped up into one.

[Dusty Bannister]

Posters to this thread might consider taking a little break before continuing beating on this guy. First he gets a beating because his grandson is not being smart and safe in his efforts to get "free lead" by breaking down auto batteries. Lots of swats to G'Pa for not stopping that. And now he is getting beat up again because he is not answering your demands fast enough to suit you. Maybe he has a family emergency? Maybe he got sick? Maybe he just decided to not participate as the whipping boy any longer?

If you can't be civil, maybe you can try being silent for a bit and let things settle down.
Dusty

[IllinoisCoyoteHunter]

Explain how you can get tension when you have an ever so slight springback in the brass? We can all agree brass has springback, right?

Winelover, maybe after multiple firings your brass was work hardening and causing even more brass springback coming out of the sizing die causing inadequate bullet tension.

[Plate plinker]

It’s not rocket science. Follow the manual get a chronograph start low and work up.

[DonMountain]

One thing all of you can say in a positive way is Mr. Mountain has proven by his post that every Harry, Dick and Tom will believe what they want and load their ammo the way they want to.
The human mind is an awesome thing. Right, wrong and indifferent all wrapped up into one.

Hello again everybody. I apologize for not responding sooner on this question. And I am not offended in any way by all of the answers to my question. In fact some of the discussion made me laugh. I am slowly proceeding on the 9mm Luger reloading job. And things are improving. I am using Winchester brass. Remington 1-1/2 small pistol primers. 3.8 grains of Bullseye with every load measured on a RCBS 10-10 scale that has been zeroed before each loading session. And an ACME+ Coated 9mm 115 RN-NLG lead projectile. I got the most improvement by measuring the mouth of the case and setting the mouth at the book measurement of 0.380". A factory Winchester round was 0.376". And my previous loadings were at 0.377". So, I carefully set my taper crimp die to just squeeze it to the maximum that will fit in my gun at 0.380". And the primers look much better with this load and an Over All Length of 1.100". But still not quite like the factory Winchester loads do. So on my next set of reloads I have increased the OAL to 1.125" and I haven't shot those yet. Another thing I have noticed, was I accidentally set one of the bullets about 0.025" deeper than intended when I was adjusting my bullet seating die. And with my Quinetics bullet puller I had a heck of a time pulling one of these loads with the case mouth still belled and not crimped into the surface of the bullet. So, I am getting an awful lot of bullet friction or tension without even crimping. My reloading is being done with a 30 year old set of Hornady dies that I have used in the past without any problems.

[Walkingwolf]

9mm is a high pressure round, unless you load negative pressure you are going to get more flattened primers than with a low pressure round like 38 spl.

If this bothers you switch to magnum primers, and reduce your load to account for the hotter primer.

[Soundguy]

My experience is like yours. I have 50 years reloading and I started out with 38/357 as my first caliber to reload. I then graduated to 45acp. my first 38/357 dies employed the roll crimp that simply rolls the edge of the case into the ring on the bullet. When I started reloading jacketed bullets I found a need to have a better crimp as the roll is worthless on jacketed. i then purchased the carbide dies and an optional tapper crimp die.

I will attempt to over crimp a 9mm bullet and post a picture for those that are either unwilling to accept the fact that taper crimping DOES apply pressure to either a lead or JACKETED OR PLATED bullet. If you still cannot understand it or grasp the concept there is no hope for you in my opinion.

Roll crimp worthless on jacketed? Very much disagree.

I shoot many many magnum and belted mag loads with big jacketed projectiles and I assure you a hefty roll crimp works just fine.

[DonMountain]

Ok, I fired the 15 rounds with the 0.380" case mouth dimension, OAL of 1.125" and the 3.8 grains of Bullseye with one stovepipe. All of the primers look good now like a factory round. So I am getting close to the solution. Since I got that one stovepipe I am going to reduce the case mouth dimension to 0.379" and increase the OAL to 1.135" to see what effect that has. I am getting close to the maximum length the clip will fit. And I may up the load to 3.9 grains of Bullseye to improve the ejection, which for several of them was within a foot of the gun on the table I was shooting off of.

[c1skout]

I thought Rem 1 1/2 primers were not to be used in high pressure cartridges. I bought a brick of them a few years ago and used them in 38 target loads.

[DonMountain]

I thought Rem 1 1/2 primers were not to be used in high pressure cartridges. I bought a brick of them a few years ago and used them in 38 target loads.

I have never read that in any reloading manuals and I usually use them in my Webley in 38 S&W. But that didn't work out since the Webley's firing pin indent is too extreme. So I switched to small rifle primers for them. And was trying to use them in low loads in the 9mm Luger. Maybe they will work out better in the 380.

[Plate plinker]

Don you are headed in the right direction keep going. The 1.100" seems like that was a bit on the short end. All guns are different, but my experience was that longer functioned better in my pickier guns than short and the extra volume is easier to work with than the dangers of shortened ammunitions. Your missing variable is the chronograph it really helped me develop my shooting. Hope you have one or can borrow one.

[redhawk0]

I shoot 9mm from an old German Luger P-08. I know...we're not apples to apples here. But...I shoot cast lead from a 124gr Lee Truncated Cone mold. My OAL for my loads are 1.150" and I use Hodgdon HS-6 (6.0gr) with Win-SP primers. I know apples to oranges isn't the best way to help here...but giving my OAL might be helpful.

[EDIT] one last thing...I checked my specs for 9mm and the stated MAX OAL should be kept below to 1.169"

redhawk

[35remington]

Stove piping is mostly likely an ejection problem from loads being on the too light side. The weak ejection throwing the case barely clear that you have noted is a clue. A looser grip on occasion may turn a barely ejecting load into a stovepipe. Taper crimping aids in feeding by removing the mouth flare and helps avoid chambering hangups, which Is a distinctly different problem than stovepiping.

Things did not add up, which is why I commented. Loads at the starting level and stovepiping which you mentioned in your first post indicate pressures will likely be low. You have further confirmed that because you further said ejection is weak. When “primer signs” contradict what is known, best to not automatically assume that primer appearance is a definitive indication of high pressure when three out of four visible and verifiable indicators say it is not.

That is why most said more info is needed. We can probably definitively say your primer problems are not pressure related. Taper crimping is not a pressure influencing variable when applied in any reasonable manner. Taper crimping should not be applied to such a severe degree that the case mouth is reduced below the SAAMI spec diameter of the front of the barrel’s chamber headspacing stop shoulder, but you would have to be taper crimping with great force to accomplish that. That dimension is smaller than anything you have mentioned using so far.

To know for sure what helped, change one thing at a time and you will find it. It is often helpful to measure the case mouth diameter of factory ammo using the same case brand to see what is a reasonable range of finished case mouth diameter. Federal 124 HST and cheapo Tula FMJ measures .377.” Hornady 135 Critical Duty, which in having a cannelure might make you think is would be taper crimped slightly smaller in diameter, is actually larger at .378”

FWIW.

I must confirm that the Remington 1 1/2 primer is not intended for full power 9mm pressure levels. It has a thin cup which will pierce. This is not a pressure sign. It just means the material the primer is made from is too soft to withstand higher pressure levels. Do not load these hot. I have pierced these myself going a little too far. These are better in the 38 Special/380 pressure range. They may work fine in 9mm if you do not increase the throttle too much.

Increasing bullet seating depth while keeping everything else the same will raise pressure. Decrease will lower it. How much depends upon how much shorter or longer.

Besides fitting the magazine, remove the barrel from the gun and make sure the loaded rounds fall into and out of the chamber freely and the base of the case does not protrude beyond the hood or chamber extension. Make sure all primers are seated a little below flush.

[Soundguy]

Agreed, the stovepipe might indicate undercharge for that gun.

[35remington]

An inexpensive chronograph gives considerable peace of mind and helps assure whether loads are within reasonable limits. When just making loads that work the gun it is not a necessity, but when questions arise it will help you determine if “high pressure” is present or not, and in terms of being a reliable indicator is much better than looking at primer appearance.