Why are my reloads "growing"

[woody2]

Yesterday I loaded 100 rounds of 9mm. Bullets were seated to an OAL of 1.142” plus or minus 0.002”. The gun has a very tight chamber so anything longer than 1.146” won’t allow the slide to lock. I seat the bullet and crimp in 2 separate operations, using a taper crimp die for the last stage, and spot check length with a caliper during seating. After seating bullets in all 100 rounds I noticed that some of the rounds appeared long, and the lube groove was visible above the case on a few of them. That prompted me to measure about 40 additional rounds and many of them ranged in length up to 1.157”.
At that point I reseated all 100 rounds, measuring each round individually immediately after reseating, to make sure lengths were in the acceptable range. I then spot checked length and found that many had “grown” to lengths up to 1.154”. Decided to let them sit overnight to see what would happen.
Meanwhile I checked the lengths on rounds I had loaded in January, March, April, and June of this year. All were 1.142” plus or minus 0.002”.
This afternoon I remeasured all 100 rounds. Forty three are within tolerance. Fifty seven have grown to lengths up to 1.154”. I reseated them and already some have started to grow. I put one in the calipers and watched it increase in length from 1.142” to 1.146” in less than a minute.
I’m loading a Lee 125 gr RN #356-125-RN over 3.6 grs of Bullseye. Cases are Remington, some once fired, some fired several times.
I’ve been reloading for over 55 years and this is the first time anything like this has happened. If anyone has any ideas about what’s happening I’d really like your input.

[reddog81]

1.14 inches to over 2 inches? That can't be right.

[BK7saum]

Sounds like you don't have enough neck tension and the air pressure inside the case is pushing the boolits back out. Also sounds like they are coming out after seating and before they are crimped.

What are you using for an expander and how close in size is it to your boolits?

[MBTcustom]

The only time I have had this happen was with a compressed load. Better check that load data.

[mongoose33]

1.14 inches to over 2 inches? That can't be right.

The boolit is floating over the casemouth. :)


The only time I have had this happen was with a compressed load. Better check that load data.

The 3.6 grains of bullseye isn't sound out of bounds; makes me wonder if it's 13.6 grains.

[Yodogsandman]

What have you changed since loading those in January, March, April, and June?

[country gent]

Are bullets tight in cases when seated and after being crimped? Hold one bullet down and tap your hand against bench top 2 -3 times and see if it grows then. I have seen compressed loads grow especially Black powder that is compressed alot more than smokeless normally is. 1.140 to 2.005 is .060 growth thats alot for air or even powder compression push back. Are your dies still thight in the press. nothing shifting or moving around?

[Bzcraig]

The only time I have had this happen was with a compressed load. Better check that load data.

This is was also my first thought and strongly suggest pulling some of those and checking your powder weight.

[country gent]

Yep it is .865 I didnt get it right in my head. At that much bullets should be falling out of cases. Cases arnt getting sized down enough or over expanded for some reason.

[bedbugbilly]

You say they are growing "after" crimping . . . but is there any chance . . . if your neck tension isn't enough . . . as in not sizing down or over expanding . . . . that your seating and or your crimp die is crudded up with lube, etc.? You don't mention how your boolits are lubed but if you neck tension isn't enough and your dies are dirty, it could "pull" on the boolit. But it seems like you would notice it when you pull the finished cartridge from the holder and put it in your tray. It might be worth cleaning your dies anyway?

I haven't had it happen with 9mm but I have had it happen with some other calibers when I was setting up my dies initially or ran across a case with very thin wall thickness at the mouth. Check your head stamps on the ones that are "growing" . . are they all the same or different?

[w5pv]

I would check the load and then check your calipers I think there may be a problem with your measuring that giving you a false reading.

[Tatume]

...1.140 to 2.005 is .060 growth thats a lot...

It appears that you were thinking correctly, but in your mind you were seeing what the OP meant, not what the OP said. You are probably correct to assume that he MEANT 1.140" to 1.200" of growth.

As others have pointed out, it is impossible for a 9mmP cartridge to attain 2.0" length.

Take care, Tom

[Tatume]

P.s., +1 on checking the charge. If in fact there is 13.6 grains of Bullseye in there, serious injury will almost certainly be the outcome if one is fired.

[MBTcustom]

P.s., +1 on checking the charge. If in fact there is 13.6 grains of Bullseye in there, serious injury will almost certainly be the outcome if one is fired.

My thought exactly. If the OP has a tendency to move decimal points and devisions, it's a good thing the only bad that has happened is the powder pushing the bullets out.
Dyslexia and reloading do not mix!
It is obvious that the OP was mixing up the numbers somehow, because there is no way a 9mm is the same length as a 308.
Misstating the length of the cartridges is a benign error, but considering the subject of this thread, I have a very real concern that his missing "1" found it's way from the OAL of the cartridge to the powder charge, and that is a very dangerous mistake.
Remember fellers, Kabooms are caused by a very small error that results in catastrophic consequences.

[dondiego]

Smokeless powder is made of nitrates, a natural fertilizer that makes things grow!

[country gent]

The OP has offered none of the asked for imformation thats been asked for as of yet. There is a definate issue here as loaded ammo doesnt normally "grow" like this. Has he change lots of brass ? Thinner brass produces less neck tension when sized in the normal dies. Changed expanders to a diffrent dia? Changed bullets a load set up for .357 dia then going to .355 loses tension also. Another issue that isnt seen alot anymore is a carbide sizing ring thats been pulled out then the case no longer gets sized down for the expander to open up. This is very obvious when looking at the die from the bottom. Also is there any chance of an alloy that has more shrinkage was used and bullets are undersized now? There is alot of questions raised here.

[Echo]

OP, what say?

[.22-10-45]

Woody..you didn't happen to add Viagara to your lube did you?

[303Guy]

Didn't anyone notice? We have a new member here! Welcome aboard, reddog8. :drinks:


Remember fellers, Kabooms are caused by a very small error that results in catastrophic consequences.Yup.

The thing about errors is that they can and do happen and they can be hard to detect.

[woody2]

Thanks for all the responses. Many of you caught the obviously incorrect "2.004" and 2.007" dimensions. Don't know why I used those numbers instead of the correct "1.154" etc. I've edited the original post to reflect the correct lengths.

Many asked what has changed since my loadings earlier in the year. The answer is nothing has changed. I prepare components for pistol cartridges in 1000 piece lots so all of the cases that I've loaded this year were sized at the same time last January using an RCBS carbide die set. They were all primed, using CCI small pistol primers, at the same time, and bagged in 100 case lots. All of the bullets were cast, sized, and lubricated at the same time last December using the same alloy and the same lube. All of the powder came from the same one pound container purchased last summer.

When loading I charge 100 cases at a time using two 50 round loading blocks. After charging the first 50 cases I visually inspect every case to assure that each case has been charged and the powder level in each case is about the same. After inspecting the first 50 cases I set them aside and charge the next 50 cases, repeating the visual inspection of each case. I set the second 50 cases aside and then perform a second visual inspection of the first 50 cases before seating bullets. After seating the first 50 cases I perform a second visual inspection of the second 50 cases before seating bullets in them.

A double charge is pretty unlikely using that method.

Nothing has changed except that some of the bullets are backing out of the cases, and that has never happened to me before. Just wondering if anyone else has had a similar experience and looking for possible causes.

[Tatume]

You still need to pull some bullets and weigh the powder charges.

[MBTcustom]

Woody, All that means is that you may have made them exactly wrong. This is giving me the heeby jeebies. Could you please pull down one or two of the ones that have grown, and carefully measure the powder that it contained? That really needs to be done.

I'm a gunsmith you see, and I get to look things over after someone has blown up their gun, and mangled themselves. I have heard explanations that "it simply must have been the guns fault because my reloading process is foolproof." Everybody says that. That's what gives us confidence to pull the trigger at the range. But by the same token, after seeing one of these guns that got cut in half by a double charge, it shook a friend of mine up so badly that he asked me to help him pull down his last batch. It sure was precious seeing the expression on his face when I dumped out a double charge. Turns out he was right. He said he just had a bad feeling about that batch. (gulp) I keep meaning to ask him to hold my loads and tell me how he feels about them. LOL!

Anyway, the first thing is to eliminate the most obvious cause of the trouble here. Verify that it is not the powder pushing the bullet back out, then we can move on to air pressure, brand of brass, gremlins, and all sorts of other things I've never seen.

[Tatume]

Nothing has changed ... and looking for possible causes.

Clearly something has changed. I have experienced this myself, and each and every time it was the result of a compressed charge. It is very easy to set up a scale incorrectly, and then the powder dispenser to deliver the wrong amount of powder. If the scale is set to the correct charge weight, then there may be something wrong with the scale itself. I have little doubt that there is too much powder in your cases, and it's likely more than a double charge (if you have 13.6 gr instead of 3.6 that's almost a quadruple charge!). If you pull some bullets and determine that I am wrong, no harm is done. You'll still have ten fingers, two eyes, and be alive.

[wonderwolf]

Are your dies clean? I realize dirty dies would make shorter rounds but just to eliminate a possibility. I'm wondering if lube build up has allowed to seat proper depth bullets then dirt/gunk shift seat longer bullets?

Is the press clean, do you have full stroke on the ram and nothing is interfering with the upstroke between shell holder and dies. Sometimes primers get in places where they shouldn't and shorten up a stroke and sometimes you may not notice.

[Virginia John]

I load 9s all the time and 3.6 Bullseye is not a compressed load. You need to pull all 100 and start over.

[Ed_Shot]

+1 for neck tension problem. What is the headstamp on the brass with growing OAL?

[woody2]

I pulled 5 rounds and weighed each powder charge. All were 3.6 grs. The powder measure is dedicated to loading this charge in 9mm so it isn't adjusted frequently. I also weigh every 10th charge.

One of the cases I'm using will hold 8.8 grs of bullseye when filled to the top of the case mouth so 13+ grs is a physical impossibility.

3.6 grs of Bullseye fills the case to a level of 0.318" below the case mouth. The bullet is seated to a depth of 0.211" inside the case so this is not a compressed charge.

The headstamp is "R-P 9mm Luger"

As I've said before, I've been loading this round for years and this is the first time I've had this problem. I'd really like to understand what's going on.

[MBTcustom]

Woody, please accept a sincere apology. I really thought you were in trouble there.
There are lots of things in this sport I have never seen, and you have just added one to the list.

I honestly have no idea why your bullets would move out of the cases if it were not the powder charge.

[reddog81]

Didn't anyone notice? We have a new member here! Welcome aboard, reddog8. :drinks:



Thanks for the welcome. I didn't even realize it was my first post. I've been visiting this site weekly for the last couple of months.


Will these rounds chamber in the gun? Is the caliper you are using electronic? some times electronic devices go bonkers when the battery gets low or they might need to be cleaned.
Out pf curiosity how many times have these cases been loaded?
My guess would be that they rounds started out at 1.54 but that doesn't appear to be the issue...

[Dusty Bannister]

I pulled 5 rounds and weighed each powder charge. All were 3.6 grs.

3.6 grs of Bullseye fills the case to a level of 0.318" below the case mouth. The bullet is seated to a depth of 0.211" inside the case so this is not a compressed charge.

The headstamp is "R-P 9mm Luger

"I'd really like to understand what's going on.

Now that those questions are answered, examine the pulled bullets carefully and measure them with a micrometer on the base driving band as well as the first band. What is the diameter of the bullets you pulled? Looking to verify if or if not, the alloy or as cast diameter might have changed and gone unnoticed. Dusty

[303Guy]

One shouldn't underestimate the effects of compressed air. If the boolits are being squeezed to a slight taper to the rear then the compressed air within and the slight taper of the case interior might conceivable push the boolit forward over time with the cyclic changes in temperature they would have undergone (we've all seen how nails will back out of timber).

Lube can be slippery stuff and should seal the case well. On the other hand it may have nothing to do with it although right now I can't think of anything else that might be causing it. Compressing that amount of air with the powder present would raise the internal pressure a fair bit.

These loaded rounds have been taper crimped right? Does that mean the case mouth is squeezed down with the boolit in it? If so then the neck tension won't be very high as brass has more spring back than lead alloy. How hard or easy was it to pull those boolits?

[Uncle R.]

...If the boolits are being squeezed to a slight taper...

...Lube can be slippery stuff and should seal the case well...

These loaded rounds have been taper crimped right? Does that mean the case mouth is squeezed down with the boolit in it? If so then the neck tension won't be very high as brass has more spring back than lead alloy. How hard or easy was it to pull those boolits?

I strongly suspect that 303Guy is on the right path here. Look for bullets being squeezed down to a "backwards taper" by neck tension at seating, followed by taper crimp reducing neck tension to almost zero. Residual neck tension or compressed internal air or both could be pushing those backwards tapered bullets forward.

Whatever it is, don't settle for "nothing is changed." Logic tells us SOMETHING is changed if the loads didn't have this problem before. Case neck hardness, bullet hardness, sized bullet diameter, lube quantity - something is changed. Approach the question like a quality control inspector. Compare old and new, measure and check and inspect to find the difference.

Compare diameters of pulled bullets with some that were never seated. Are the case necks squeezing the bullets too small? Check for a taper on pulled bullets. Are they smaller at the base than in the area of the crimp? If they are tapered they might move forward all to easily. Compare outside case neck diameters before and after seating to see if bullets are "bulging" the cases. Compare case diameters before and after taper crimping to see if cases are bulging behind the taper crimp. Check bullet tension by pushing them into the case against a scale. Check before and after taper crimping.

It's very likely that something is reducing case neck tension to near zero. Put on your detective hat and find that something.

Good luck in your quest, and please let us know what you discover. There's something to be learned here for all of us.

Uncle R.

[Grump]

What boolit are you casting up for these 9mms?

3.6 of BE is .3 gr over what I believe Alliant recommends in 9mm, but YMMV.

Longer boolits could be getting the wedgie treatment at the back, and lube could make it possible for the brass to squeeze the bullets at the back like you do with toothpaste, just a lot slower.

Other than that, the only thing I have personally experienced is powder compression. That OAL growth thing identified some thin-necked rifle brass for me a few years ago.

Watching the boolit ease out is a clue by itself, assuming no hallucinations...and Occam's razor makes me discount THAT possibility!

IME, the only way for captured air to push a bullet of any variety out is for there to be too little neck tension. That's been covered adequately above IMO. But I must recommend that you take an empty, sized, NOT primed, expanded case and seat a bullet in it, then thumb the base of the cartridge with the bullet nose on the benchtop and see of you can push the bullet IN. Even if you can't, grab the bullet and case each in pliers and then see how easily you can pull the seated bullet out. If it's hard, repeat the tests with a fired primer seated and your powder charge and see if there's a difference. To isolate any air effects, repeat with a piece of paper at the bottom of the case to keep the powder from spilling out...

The fact that nothing has changed may simply mean that you have had this problem for a long time but some storage variable has led to more growth, enough to notice.

[shooter93]

The neck tension seems the most likely.....how many times has this brass been fired? Along with the thoughts on bullet compression etc. has the brass been work hardened and contributing to low neck tension? As was noted....and no one here is picking on you.....logic dictates that SOMETHING has changed if you never had this problem before.

[243winxb]

Neck tension is to light. Buy Lee Undersized Carbide Sizing Die 9mm Luger and check expander diameter, it may be to large. http://www.midwayusa.com/product/386755/lee-undersized-carbide-sizing-die-9mm-luger

[BK7saum]

I strongly suspect that 303Guy is on the right path here. Look for bullets being squeezed down to a "backwards taper" by neck tension at seating, followed by taper crimp reducing neck tension to almost zero. Residual neck tension or compressed internal air or both could be pushing those backwards tapered bullets forward.

Whatever it is, don't settle for "nothing is changed." Logic tells us SOMETHING is changed if the loads didn't have this problem before. Case neck hardness, bullet hardness, sized bullet diameter, lube quantity - something is changed. Approach the question like a quality control inspector. Compare old and new, measure and check and inspect to find the difference.

Compare diameters of pulled bullets with some that were never seated. Are the case necks squeezing the bullets too small? Check for a taper on pulled bullets. Are they smaller at the base than in the area of the crimp? If they are tapered they might move forward all to easily. Compare outside case neck diameters before and after seating to see if bullets are "bulging" the cases. Compare case diameters before and after taper crimping to see if cases are bulging behind the taper crimp. Check bullet tension by pushing them into the case against a scale. Check before and after taper crimping.

It's very likely that something is reducing case neck tension to near zero. Put on your detective hat and find that something.

Good luck in your quest, and please let us know what you discover. There's something to be learned here for all of us.

Uncle R.

I understood that the boolits were seated only and backed our before they were crimped.

Brad

[Yodogsandman]

Woody2, I'd go back and re-check the C.O.A.L. of all the cartridges loaded up in those prior months just to be sure that this isn't a recurring problem, that you just now caught. Something could be loosening up on you or you might have some worn tooling that's stripped or cracked. You HAVE been loading these the same for years.

I'd also suspect the crimping operation has changed.

Your loading practices seem sound and none made it to the range before you found out. Good catch!

[Ranger 7]

If it is any help, I had the same problem once. 9mm 124 Gr. Lee. TL. (not sized) The cast bullets were a bit oversized and the case would just squeeze them out.
Ran the batch through the sizer, problem gone.

[303Guy]

Well, I have learned something new here. I would never have suspected this could happen.

I've mentioned before that I loaded my hornet by gluing the bullet into the neck using a paper towel cup and dipping the upturned bullet and neck into molten 'waxy-lube' which warmed the case and expelled air and sealed the neck. The negative pressure in the case no doubt helped hold the boolit in place. At any rate, the expelled air wasn't going to push the bullet out which it may have when the case warmed up and the waxy-lube softened. As is was, the bullet stayed firmly down on top of the compressed powder charge (pre-compressed that so so as not to push the bullet out).

[woody2]

I suspect that neck tension, as suggested by 303guy and several others, is a big part of the problem, along with air compressed in the case. For those suggesting a compressed charge, it isn't. 3.6 grs of Bullseye, as I previously stated, fills the case to a level 0.318" below the case mouth. The base of the bullet is seated to a depth of 0.211", leaving an air gap of 0.107". This is not a compressed charge. As far as a double charge is concerned, I tried it to see what it looks like and saw that it filled the case nearly to the top. Since I visually inspect each charged case twice before seating bullets a double charged case isn't going to slip through unnoticed. This morning I threw 10 charges of 3.6 grains, took them to a reloader friend, and reweighed them on his scale. They were all within a range of 3.6 grains plus or minus less than 0.1 gr.

I also miked the 5 bullets I previously pulled, as suggested by Uncle R. and compared them to bullets that have not been seated in cases. Four of them measured 0.357", one measured 0.356". Note that none of them have been crimped. They were only seated.

Today I selected 10 once fired cases and 10 cases from the batch the problem cases came from and measured the OD of each case. The cases were numbered and then resized. Immediately after sizing I measured each case and recorded the data. Tomorrow I'll measure them again to see how much springback has occurred. I'm also going to chamber some of the rounds to see how much, if any, setback occurs.

One last item - I've repeatedly reseated 52 of the 57 bullets that backed out of the cases. As many as 3 times per day. Tonight 36 of them have remained at 1.142" since last night and the remaining 16 are about 1.146".

[Grump]

Sorry, my post about the powder charge skipped that I was tracking down baesed on it being the longest, the 147. I don't remember it being explicitly stated, but it sounds like you are loading a 124-GR bullet.

You say the powder has a tiny bit more than .10 of room. Please double-check that.

But it what I don't see here (unless I missed it) is what your sized necks measure before seating the bullet and what they measure after seating the bullet. If there is no change, I bet you at least a doughnut that insufficient next tension is the real culprit here. Entrapped air can easily push bullets back out if there's hardly any grip.

[woody2]

The air gap between the top of the powder charge and the base of the bullet is about 0.107". I'll seat some bullets and measure case diameters tomorrow and let you know the results.

Today I chambered 10 rounds, measuring OAL before and after chambering to see if there was ant setback. Two had no setback, one had 0.001, three had 0.002, one had 0.003, and three had .004.

[blaser.306]

OK , I'll admit it. It is too early in the day and before work to go thru 3 pages of posts , so accept my apologies if this has been covered off. What kind of lube is being used? If it is a tumble lube , might it not just be lubing up the deriving bands ( bearing surface ) and helping the boolit with its exit plan. Those little bitty 9mm cases are tapered are they not?

[David2011]

OK, it's way past work and I read the whole thing. I recall seeing boolits come back out of the cartridges during a loading sessions some time ago. I seated a few and then noticed that they were longer than the seated length. Seated another, set it down and watched the boolit come back out a noticeable amount. I don't remember what cartridge I was loading or anything useful other than figuring out it was air pressure.

David

[woody2]

[QUOTE=David2011;3312952]OK, it's way past work and I read the whole thing. I recall seeing boolits come back out of the cartridges during a loading sessions some time ago. I seated a few and then noticed that they were longer than the seated length. Seated another, set it down and watched the boolit come back out a noticeable amount. I don't remember what cartridge I was loading or anything useful other than figuring out it was air pressure.

Thank you, thank you, thank you. That's exactly what I think is happening. Did you fire them and was everything ok?

[Wayne Smith]

I had this happen with the 45-70 that I was literally thumb seating boolits in fired cases without sizing. It was a Trapdoor. This was the most accurate way to load for that rifle, with no tension, and the weight of the boolit and the lube acting as glue. Every once in a while the situation would be that a boolit would start sliding up. I figured that the case was just a little tight and did not let the air escape as I seated the boolit. I had a couple that I could push the boolit down and feel the bounce of the air compression.

[opos]

I came in late...and I don't load 9mm any more but I got a question...or more of a comment/question. I read you say the brass is all R/P..correct? Are you using Lee dies?..here's why I ask...I was loading 38 special some time ago...loading with Lee carbide dies...I load one at a time in a single stage...I got to the bullet seating part and found that I had a random number of bullets that were loose in the case...didn't "look loose" but were "finger push" loose...went back through and found they were all R/P brass...measured all the brass "thickness" at the case mouth and found that the R/P brass was about .002 thinner than the other manufacturers brass on average....contacted Lee....sent them some of the brass..some of the bullets, etc...they found that their dies that I had were right at the limit for size and the brass was at the other end of the scale so the accumulated error was significant enough to cause the light throat tension..they replaced the sizer die with a different one and all has been right on target since...

I would think with the 9mm cartridge shape and no roll crimp that you might be seeing the bullets sort of "hydraulic" out of the cases from air pressure built up inside when you seat the bullets...

Just another place to look.

[woody2]

I came in late...and I don't load 9mm any more but I got a question...or more of a comment/question. I read you say the brass is all R/P..correct? Are you using Lee dies?..here's why I ask...I was loading 38 special some time ago...loading with Lee carbide dies...I load one at a time in a single stage...I got to the bullet seating part and found that I had a random number of bullets that were loose in the case...didn't "look loose" but were "finger push" loose...went back through and found they were all R/P brass...measured all the brass "thickness" at the case mouth and found that the R/P brass was about .002 thinner than the other manufacturers brass on average....contacted Lee....sent them some of the brass..some of the bullets, etc...they found that their dies that I had were right at the limit for size and the brass was at the other end of the scale so the accumulated error was significant enough to cause the light throat tension..they replaced the sizer die with a different one and all has been right on target since...

I would think with the 9mm cartridge shape and no roll crimp that you might be seeing the bullets sort of "hydraulic" out of the cases from air pressure built up inside when you seat the bullets...

Just another place to look.

Interesting. I'll measure some of the cases. I've reloaded some of these cases before, though, and everything was normal.