Certaindeaf
member
No problem. It seemed you were being condescending/demeaning. I try.
I think we all wish our reloading brother the best.. perhaps I was too quick on the (very genteel) trigger.
Had a KB! How do YOU properly check case crimp???
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I think we all wish our reloading brother the best.. perhaps I was too quick on the (very genteel) trigger.
Neutered10mm
Member
Bullets are spot on .400, both new and those 3 pulled from the 5 remaining in the mag. I made another dummy round, measured it out with a neck of .423, a waist of .419 and a web of .423, and finally an OAL of 1.131. I then put it on the scale and began leaning into it as hard as I could (53.7 lbs) with my thumb and then measured OAL again ... 1.131 ... didn't budge!
The current press setup is spot on. I now know that these were early rounds and more than likely this was caused by over belling, and then subsequently the "crimp" contributed to diminished neck tension, which caused the bullet to setback during recoil and chamber feed. I also tested some of the remaining 35 rounds from that batch and again, the bullet starts to setback under around 30 lbs. of pressure with my thumb on pressing the bullet against the scale.
Make of that info what you will because I don't think there is a bathroom scale thumb press pressure standard
The current press setup is spot on. I now know that these were early rounds and more than likely this was caused by over belling, and then subsequently the "crimp" contributed to diminished neck tension, which caused the bullet to setback during recoil and chamber feed. I also tested some of the remaining 35 rounds from that batch and again, the bullet starts to setback under around 30 lbs. of pressure with my thumb on pressing the bullet against the scale.
Make of that info what you will because I don't think there is a bathroom scale thumb press pressure standard
Neutered10mm
Member
rsrocket1 - The round wend down range and hit about 6 inches down and left of the bulls eye.
I've been holding out on you guys ... I have the event on video ... here are two successive screen grabs. The first is of the round exploding, the second is of the round down range.
I've been holding out on you guys ... I have the event on video ... here are two successive screen grabs. The first is of the round exploding, the second is of the round down range.
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MtnCreek
Member
Anybody know how much force is placed on the cartridge when hitting the feedramp and from recoil in the mag??? Anyone care to take a guess at how that would compare to the impact the cartridges in the mag took during the KB???
Mr. Cougar, You're still holding out on us. Where's the screenshot from when you turned to the camera with a dazzed look?
Mr. Cougar, You're still holding out on us. Where's the screenshot from when you turned to the camera with a dazzed look?
Neutered10mm
Member
LOL, after the gun flew from my hand as I stumbled back into the camera, the wife who was holding the camera continued to film as I "walked it off" while the range master climbed over the bench and assessed the situation. My hands felt like they had frostbite for about 2 minutes - a severely painful tingle/numbness - hard to explain. Sorry to disappoint, no such film exists
gunnysmith
Member
When you take the cartridges apart, would you check the interior of the case to determine if there is a "lip" where the "buldge" was removed.
I would greatly appreciate it if you could.
To this point in my reloading I have not used Bulged cases nor attempted to remove them.
I have only one pistol with an unsupported chamber.
I would greatly appreciate it if you could.
To this point in my reloading I have not used Bulged cases nor attempted to remove them.
I have only one pistol with an unsupported chamber.
gamestalker
member
As stated by others here, the crimp station or step in seating bullets for an auto loader straight walled case, is not to enhance or produce neck tension. Straight walled auto loader cases such as the .40 S&W head space at the mouth so distorting the mouth by crimping is going to have the potential to cause serious problems as follows, and as you've unfortunately discovered.
If the case mouth is closed too much during the removal of the belling step, the entire loaded round can chamber too deep in the chamber which would allow the mouth to get pinched in the throat. When the mouth gets pinched, it can't expand during discharge, thus delaying or preventing the gases and bullet from escape freely from the case, the result is a KB. There are other undesired effects less catastrophic, yet still potentially dangerous, or damaging to the firearm.
Something that may not be acceptable for everyone, as it could possibly restricted by the type of press or bullets being used, is to seat bullets without belling the mouth. I've been doing it this way for at least a couple of decades. I make sure each case mouth is reamed and chamfered and since I don't load non jacketed bullets the need for belling the mouth is unnecessary.
However, if you are going to bell the mouths, make certain that the die is adjusted just enough to only remove the bell and not actually effect a crimp. neck tension for AL cartridges is 100% produced by the resizing die producing the correct internal mouth/neck dimension, not the crimp.
Also be careful not to bell the mouth more than is necessary to allow the bullet to seat without shaving and no more.
If the case mouth is closed too much during the removal of the belling step, the entire loaded round can chamber too deep in the chamber which would allow the mouth to get pinched in the throat. When the mouth gets pinched, it can't expand during discharge, thus delaying or preventing the gases and bullet from escape freely from the case, the result is a KB. There are other undesired effects less catastrophic, yet still potentially dangerous, or damaging to the firearm.
Something that may not be acceptable for everyone, as it could possibly restricted by the type of press or bullets being used, is to seat bullets without belling the mouth. I've been doing it this way for at least a couple of decades. I make sure each case mouth is reamed and chamfered and since I don't load non jacketed bullets the need for belling the mouth is unnecessary.
However, if you are going to bell the mouths, make certain that the die is adjusted just enough to only remove the bell and not actually effect a crimp. neck tension for AL cartridges is 100% produced by the resizing die producing the correct internal mouth/neck dimension, not the crimp.
Also be careful not to bell the mouth more than is necessary to allow the bullet to seat without shaving and no more.
Neutered10mm
Member
would love to test feed the rounds in my glock ... oh wait
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Neutered10mm
Member
OK, first and foremost, I think the term "bulge" means drastically different things to different people. For example, a new reloader/shooter like myself, I call this a bulge, whereas some here might consider it "expanded".
However, when I run it through the press WITHOUT running it through the Lee de-bulge kit first (with Lee FCD w/internals removed), I get this crease in the web area. Said crease is substantial enough to feel with the finger nail:
brass that has been de-bulged does not show this crease.
Back to what some consider a bulge and what other consider expanded ... what would you call this brass? 99% of my brass looks like this ... the other 1% does as well, but is getting tossed due to neck dings and such ... nothing nearly as bulged as this:
However, when I run it through the press WITHOUT running it through the Lee de-bulge kit first (with Lee FCD w/internals removed), I get this crease in the web area. Said crease is substantial enough to feel with the finger nail:
brass that has been de-bulged does not show this crease.
Back to what some consider a bulge and what other consider expanded ... what would you call this brass? 99% of my brass looks like this ... the other 1% does as well, but is getting tossed due to neck dings and such ... nothing nearly as bulged as this:
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Neutered10mm
Member
you have nailed it ... I suspect that this round of bullets was from over belling and then subsequent over crimping ... again, showing my son the process, I think I forgot to reset the press. I then made the potentially fatal mistake of not redoing any of the rounds after resetting the press. Apparently my changes have worked quite well as my "bell" is barely enough to get the bullet to wedge into the mouth, barely measurable, and my rounds produced since fired excellently. My recently produced dummies are measuring coke bottle specs with a "waist" about .010 less than the neck or head. Knowing the potential for disaster, I can confidently say that I now know what to look for and what not to do in my routine to produce safe rounds.
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Neutered10mm
Member
^^ forgot to include my reasoning for the "nailed it" ^^
I remember pulling a VERY tiny ring of brass out of the barrel after removing the shell ... I don't have a pictures of it, but it couldn't have been more than .01" thick ... can't believe I had forgotten to mention this! Is that a Tell tail sign of what you are describing? Sure as hell sounds like it to me ... damn, still can't believe I forgot to mention this (had to go back and read everything I had written concerning my retelling of the event).
I remember pulling a VERY tiny ring of brass out of the barrel after removing the shell ... I don't have a pictures of it, but it couldn't have been more than .01" thick ... can't believe I had forgotten to mention this! Is that a Tell tail sign of what you are describing? Sure as hell sounds like it to me ... damn, still can't believe I forgot to mention this (had to go back and read everything I had written concerning my retelling of the event).
A ring of brass in the leade of the chamber? Yeah, that sure sounds like the culprit.
Here's another oddball to watch out for. I have NO CLUE how I didn't notice this while seating.
So I'm out shooting and my G27 has a jam. I rack the slide, and the round chambers. I pull the trigger and get a click. When I jack the round out, the nose is setback nearly flush with the case mouth!
Somehow I managed to fill an unsized case with powder, seat a bullet over it, load it into a magazine, and then get it chambered (even though it set back so far it tried to jam on the feedramp, and I still didn't notice). I wouldn't have thought this many mistakes was even possible.
So there are more than a couple ways to kB a gun out of the blue without doublecharging. This is one reason I wouldn't consider decapping with a universal decapping pin before sizing, unless I had a good reason.
I understand one of the reloading companies only accepts customer brass with primers still in them. I always thought it was so they could tell if it was once fired or not. Now I wonder if it's to reduce the chance for making a mistake such as this, but with a live primer.
Here's another oddball to watch out for. I have NO CLUE how I didn't notice this while seating.
So I'm out shooting and my G27 has a jam. I rack the slide, and the round chambers. I pull the trigger and get a click. When I jack the round out, the nose is setback nearly flush with the case mouth!
Somehow I managed to fill an unsized case with powder, seat a bullet over it, load it into a magazine, and then get it chambered (even though it set back so far it tried to jam on the feedramp, and I still didn't notice). I wouldn't have thought this many mistakes was even possible.
So there are more than a couple ways to kB a gun out of the blue without doublecharging. This is one reason I wouldn't consider decapping with a universal decapping pin before sizing, unless I had a good reason.
I understand one of the reloading companies only accepts customer brass with primers still in them. I always thought it was so they could tell if it was once fired or not. Now I wonder if it's to reduce the chance for making a mistake such as this, but with a live primer.
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I think we have a winner. An over crimped case causing it to get the case mouth pinched between the bullet and the barrel and a serious overpressure. Caused by a halt in the normal reloading routine and a distraction.
An expensive lesson, but thankfully no permanent loss of people or major injury.
Neutered10mm
Member
I haven't produced any ammo since this happened this past weekend ... the only thing I have done is produce a few rounds to test my press setting and retest my rounds as we have been discussing.
jr_watkins
Member
FastCouger, you bring up the exact question I have had for years, ever since first hearing about "glock bulge". IMO, unsupported barrel really means "not fully supported" and any problematic stretch in the brass would look like the photo with the bulge isolated to one section. All my 40 brass looks like your photo's, with swelled area just ahead of the thicker base brass. This is the case if shot through a Glock barrel or through a Wilson Combat barrel I have. The brass fails the case gauge test (because it binds at the 360 degree bulge) if reloaded on a Dillon Square Deal B press. the loaded rounds still feed into the Glock barrel, but only some fit into the Wilson Combat (slightly tighter dimension).
Is this 360 degree stretch caused by the "not fully supported barrel" and if so how? The area of the stretch is well forward of the small area that isn't supported. If not, this stretch must be just where the case headspaces and seals the gas.
Can anyone clarify this for me?
Is this 360 degree stretch caused by the "not fully supported barrel" and if so how? The area of the stretch is well forward of the small area that isn't supported. If not, this stretch must be just where the case headspaces and seals the gas.
Can anyone clarify this for me?
rcmodel
Member in memoriam
Note the thicker case web taper further back near the case head.
The most expansion occurs in the thinner case wall further foreword.
It takes some serious over-pressure to make the bubblegum bulge at the feed ramp cut.
rc
The most expansion occurs in the thinner case wall further foreword.
It takes some serious over-pressure to make the bubblegum bulge at the feed ramp cut.
rc
Well, if the ammo is loaded hot enough, and the action opens early enough, the brass can still be under considerable pressure at the time of extraction. It seems like this would be the only way for the brass to bulge that high.
This is one of those things where I wonder if everyone isn't on a different page. The smilies are obviously made by the unsupported ramp area of the chamber. The higher up bulges would appear to be related to the action opening early. "Unsupported barrel" isn't the answer for everything, in MY book. I've tried to have this discussion with a very well respected reloader on the forum, and he seems to think that chamber support is all that matters in this caliber when hotting up your loads. Perhaps it is true when you're using faster powders. But I know I can get my G27 to malfunction with hot loads of a slow powder without making smilies. The chamber support doesn't appear to be the limiting factor in this particular case.
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rcmodel
Member in memoriam
A minimum spec cartridge in a Max spec loose chamber will bulge ahead of the web at normal pressure.
rc
rc
Certaindeaf
member
There are two ways to find "tiny rings of brass//copper/lead".. one is by seating the bullet into an unchamfered/unbelled case and the other is upon chambering.. the chamber shoulder could shave some bumped up (from perhaps an overzealous crimp) copper/brass/lead from the bullet itself.
Were it the former, it would have had maximum neck tension and were it the latter, from too little maybe. This in and of itself, to me, given all the facts, is essentially a non-issue.. or poses more questions than answers.
Were it the former, it would have had maximum neck tension and were it the latter, from too little maybe. This in and of itself, to me, given all the facts, is essentially a non-issue.. or poses more questions than answers.
RC, I believe you're correct. But I also seem to recall seeing pictures of smilied brass where the crease occurs too high. Is it not the case that a piece of 40 brass can bulge during extraction? I've also seen entire lots of badly guppie bellied Speer once-fired, where the bulge seemed abnormally high, mostly on one side. No creases, but the bulge seemed too far up to be the normal placement of the ramp while the action is closed. But I've never seen a Glock Gen2 barrel firsthand, so maybe it's just the chamber shape, afterall.
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rcmodel
Member in memoriam
If pressure were still high enough to bulge a case during extraction?
It wouldn't come out of the chamber and the rim would tear off.
An expanded case is locked in place until pressure has dropped enough for it to contract and let go of it's grip on the chamber wall.
Even blow-back firearms like most .32 ACP's and all .22 RF's have enough inertial delay built in to keep the case in the chamber until pressure drops enough to allow it to be extracted.
rc
It wouldn't come out of the chamber and the rim would tear off.
An expanded case is locked in place until pressure has dropped enough for it to contract and let go of it's grip on the chamber wall.
Even blow-back firearms like most .32 ACP's and all .22 RF's have enough inertial delay built in to keep the case in the chamber until pressure drops enough to allow it to be extracted.
rc
Neutered10mm
Member
Think about what was just said and then consider the length of time a nano-second is ... mind-boggling what goes into slinging lead down range!
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