Light charge high pressure ???

[Ball Caster]

What happened!!! I was shooting my 6.5 x 55 with 16 grains of 4227 and a 3/4 gr tuft of Dacron against the powder behind my 140 grain cast bullet. On the second shot the gun locked up and I could not open the bolt.

I tapped the bolt open but left the shell in the chamber. Later I removed the shell with a brass ramrod.

I do not think I double charged the shell but I have never used Dacron filler before, could it have been the culprit?

The gun seems otherwise unscathed.

[Crusty Deary Ol'Coot]

Ball Caster,

Have always avoided fillers, so will follow the replys with interest!

Crusty Deary Ol'Coot

[44man]

Sounds like an S.E.E. event. Boolit moved out to the rifling, stopped and the powder went off.

[popper]

I've not had any problems with dacron in 30-30. I am not familiar with 4227. If that powder is not good for light loads, dacron may not solve the problem.

[runfiverun]

i doubt it was the dacron. [i don't think 4227 "needs" dacron to help sd's or to burn properly]
your case neck might have been too long.
the boolit jammed into the rifling might have raised initial pressure too quickly.
this wasn't a "see" event.

[Crusty Deary Ol'Coot]

Runfiverun, just may have nailed it, as 4227 isn't one of the slow powders which give the S.E.E. effect from what I've read.

That is more a slow rifle or hand gun powder thing, 4831 and H110 etc.

CDOC

[Rocky Raab]

I agree that it wasn't an SEE with that quick a powder. But it is another scary event involving filler in a bottleneck case.

Just sayin'

[cbrick]

Have always avoided fillers, so will follow the replys with interest! Crusty Deary Ol'Coot


I agree that it wasn't an SEE with that quick a powder. But it is another scary event involving filler in a bottleneck case.

Just sayin'

Over the years I've heard just enough such stories involving filler to keep me from messing with it.

Just sayin'

Rick

[MtGun44]

+1 on cbrick

Bill

[runfiverun]

there are places for everything and filler has it's uses.
i generally don't use it,but i DO use it where it's needed.

[44man]

If that is a military Swede, they have a very long lead to the rifling and you can't get near it with a boolit. Low neck tension or too much primer pressure can pop the boolit out to stop at the rifling.
Powder speed really doesn't matter if it did not ignite right away.
The small amount of powder might have migrated through the filler slowing ignition.
I would dump the filler, get some neck tension and crimp the boolit in.
Never say never, it was still an S.E.E. event. That boolit moved and stopped.

[btroj]

We can all imagine what happened but in the OP it was mentioned that is can't be guaranteed to not be a double charge.
Fillers could be a problem, but no real hard data on that either.

I personally would bet it was an overcharge.

[Rocky Raab]

If it was a double charge, I'd bet a dollar our lucky friend uses loading blocks.

[44man]

We can all imagine what happened but in the OP it was mentioned that is can't be guaranteed to not be a double charge.
Fillers could be a problem, but no real hard data on that either.

I personally would bet it was an overcharge.
Never to be known of course. 4227 meters fine but I still weigh all of my charges with any powder except H110 or 296 and most ball powders. Anything that looks like a stick no matter how small will go on the scale.
I hate progressive loaders, I will never trust the powder dump.
BUT, if the charge was right, what other thing can be blamed? I feel it is hasty to blame a double charge, it is not that common with a rifle, unlike those that consider 1000 rounds of pistol ammo an hour good loading practice.
But I agree with you, we just don't know so I will always go with the most logical solution.
I have had "EXPERTS" here that I had to rant on about how they were loading and it amazes me how little knowledge they actually had. I would not allow the way they loaded.
To have friends here and to worry about them concerns me.

[45-70 Chevroner]

Runfiverun, just may have nailed it, as 4227 isn't one of the slow powders which give the S.E.E. effect from what I've read.

That is more a slow rifle or hand gun powder thing, 4831 and H110 etc.

CDOC

Second that, his load was only "1 gr. less that minimum" that is hardly a reduced load and less than 10%. If it was a double charge he is lucky it did not come apart. I think the culprit was the filler. I never use filler in a bottle neck and hardly ever in a straight case.

[Larry Gibson]

"I do not think I double charged the shell "

If you do not "know" a double charge can not be ruled out. I also think this was a double charge unless the dacron was left out. If that occured then an SEE might have been possible as 16 gr is below the recommended starting load for 4227 with a 140 gr cast bullet in the Swede. 4227, like 2400, has ignition problems with reduced loads in larger cases. However, a double charge is more likely the culprit.

Larry Gibson

[44man]

"I do not think I double charged the shell "

If you do not "know" a double charge can not be ruled out. I also think this was a double charge unless the dacron was left out. If that occured then an SEE might have been possible as 16 gr is below the recommended starting load for 4227 with a 140 gr cast bullet in the Swede. 4227, like 2400, has ignition problems with reduced loads in larger cases. However, a double charge is more likely the culprit.

Larry Gibson
Both of your explanations are correct. We just will never know which.

[tomme boy]

How much filler and how was it put in the case? Did you tamp it down?

[btroj]

Larry, is 16 gr of 4227 really that low a charge? And I don't consider a 6.5 x 55 a "large case". I also think the filler would vastly improve ignition of the powder as it is held against the primer.

I still vote for double charge. And I agree with Rocky, a loading block is often a culprit. Never use them any more.

[Ball Caster]

I think the information on max. case length may have been the problem. Max. case length is 2.165” mine measured 2.158” to 2.165”. I had annealed the cases and neck sized but did not check the length. It is possible I had a long necked case. They are now all 2.150”.

I found that my cast bullet touches the rifling with an OAL of 2.975” I seat the bullets to 2.945”.

I am loading 20 grains of IMR 4895 and have been told that Dacron pressed against the powder, will provide better ignition. I have had no problems with 140 grain jacketed loads at 36 grains of IMR 4895 but when I switch to 140 cast bullets and a light charge the group size doubles.

I would really like to find a nice cast load, I have the mold and sizing dies and the 20 grains load is pleasant to shoot.

I do not think a double charge was the issue because I measure, weigh, than seat the bullet. I only load 20 to 40 rounds so the time to measure each charge is not an issue.

[Rocky Raab]

Skip the filler. It isn't needed with either of those powders - and just may have been the problem.

I applaud your "weigh, fill, seat" procedure, as it absolutely, positively prevents the chance of a double charge.

[tomme boy]

Was the filler pressed all the way to the powder? As in you push the filler flat up against the powder so there was a air space between the filler and the boolit? If this is how you did it, you better check your chamber for a ring. It creates a bore obstruction doing it this was and would explain your high pressure.

[Crusty Deary Ol'Coot]

Ball Caster,

An overly long case would provide the same type of problem as has been seen and recorded when .308 brass was formed to .243 without the .243 case neck being reamed or outside turned after forming.

In both cases, even with the difference in cause, the problem is that the case is not able to release it's grip on the bullet and the pressures go sky high.

Consider yourself very lucky!

I was for quite awhile with the .308 to .243 forming and thankfully was provided an story of a fellow distroying a really nice pre-64 Winchester before it was too late.

Did see a friends Sako bolt come out in pieces once and the primer hole was so big in the fired case, you could put the fired primer in the hole and rattle it around.

Guess we both lucked out, as the friend put the extractor and spring etc. back in place and was good to go. That was on a .243 Ackely Improved, so probably VERY high pressures.

That was likely in the 70s.

Crusty Deary Ol'Coot

[swheeler]

Ball Caster; I will be the odd man out here and say it was caused by your choice of powder and a too light loading. Save the 4227 for your 357 mag and heavy bullets, as I do now. SEE what I mean?

[dromia]

Over the years I've heard just enough such stories involving filler to keep me from messing with it.

Just sayin'

Rick

Concur!

It still seems too uncharted an area for me to want to go there in bottle neck cases with smokeless powder.

[Ball Caster]

The reason I selected IMR 4227 is it is listed in the new Lyman Cast Bullet Handbook as a "potentially most accurate load" at 17 grains, yet my 1967 Lyman handbook shows a 23 grain load of 4227 as most acurate of all the powders listed with the 140 grain Lyman #266469 mold.

I have an old can that I have used with my 357 before switching to Trail Boss.

I also see the the new cast bullet handbook has dropped the 6.5x55mm loadings for IMR 4895 which I was using for both cast and jacketed bullets. I assume this was because there are better powders availble.

[tomme boy]

You still have not answered if you tamped the filler all the way down against the powder. Anyone else think this could be the problem?

[Ball Caster]

Tomme boy,

Your point was well taken. I set the case on end and tamped the dacron puff ball in with an allen wrench.

It took several pokes to get all the dacron into the case and set against the powder, so yes I would say that I had it pressed up against the powder.

I weighed each tuft and they were all between 1/2 and 3/4 grain and fluffy. I would not have expected it stay compressed.

I had fired 6 rounds with 4895 with no problem then I switched to my 4227 loads and the second shot locked up the bolt.

You can see my confusion as I have loaded numerious 140 grain jacketed bullets with no problems.

I have been told that light loads of 4895 and 4227 can be erratic unless the powder is at the back of the case. Once again it seems a little knowledge can be a dangerious thing. :)

Those cast loads were sweet to shoot out of my 18 inch barrel and I would really like to perfect a reliable load.

[cbrick]

Ball,

Just so I don't have to drag out both books (as you mentioned in post #26) does either of the Lyman books mention the use of fillers?

Rick

[Larry Gibson]

Ball Caster; I will be the odd man out here and say it was caused by your choice of powder and a too light loading. Save the 4227 for your 357 mag and heavy bullets, as I do now. SEE what I mean?


+1.

It was not the dacron filler. It was either a double charge or too light a charge of the wrong powder. I refer to proper powder choice in my post in the sticky "filler".

Larry Gibson

[swheeler]

+1.

It was not the dacron filler. It was either a double charge or too light a charge of the wrong powder. I refer to proper powder choice in my post in the sticky "filler".

Larry Gibson

Agreed 100%

[tomme boy]

If that filler was pushed all the way against the powder and tamped down, it could create a bore obstruction. That would act as a double charge causing the bolt to lock up. That's why I was asking.

If it was not that, it might be a SEE if it was a military gun. They seem to be the main culprit when SEE is mentioned.

[Ball Caster]

Well gentlemen, a lesson has been learned. I used a Dacron filler because I was told that a light load might give inconsistent results if the powder was not up against the primer. I never used a filler before and I suppose I should have asked for details.

I am using the Starting Loads as suggested in both my 1967 and the latest Lyman handbooks. Neither of them suggests the use of a filler.

The lesson learned of course is details, details, details, I am pretty sure I did not double charge but I am human. My case Trim to Length Dimensions were all at the long end of the tolerance and I might have had an extra-long case. Or, it is possible I packed the filler in to tight. These are all points to consider.

I want to thank the folk who have helped me and wish them all good shooting in the New Year.

Merry Christmas
Ball Caster

[Rocky Raab]

You have my sincerest congratulations. There are far too many who would say "It can't have been me, so what else can I blame."

You may or may not be at fault here - we'll probably never know. But you 'fessed up that it might be, and have learned from that. Bravo.

[unique]

There are so many theories about 'SEE' I am convinced it is sort of like religion where everyone has there own view of it. So when someone says it was or wasn't a 'SEE' I am not sure they are all talking about the same thing. 'SEE' has been described as pressure waves building up, bore constriction due to hang fire (of sorts), or to random powder detonation just because.

Anyway, one possibility based upon some testing I did is powder position and follows hang fire scenario. Typically, if you have large case relative to powder volume and tilt muzzle up before firing you will get higher velocity/pressure than if you tilt muzzle down before firing. Makes sense in terms of powder location relative to primer meaning if you tilt muzzle up before firing then powder will tend to bunch up near primer flash hole.

Now every so often when you tilt muzzle down before firing you can get some really serious velocity/pressure increases and the reason is a sort of quick hang fire where bullet is pushed in lands/bore by primer force before powder begins to burn since powder is away from primer flash hole. If you do this often enough you can even perceive the click/boom. Three powders I experimented with were 2400, IMR4227, Reloder 7 with the latter having the wildest variations which makes sense since it is slowest of the three meaning takes a little more to light.

Now given the Swedes generous throat I can envision the bullet is lodged further down the bore before stopping and powder burn really would be inhibited because of rapid expansion of powder of volume. That is to say, as bullet move down towards lands the volume occupied by powder expands and has 'chilling effect' on temperature of powder so burning is retarded until bullet stops in lands. That is well know physics at work with result that a bullet is lodged in the bore and not moving so when powder does take back off pressures will soar since start pressure for even a lead bullet in the lands is much greater than normal.

Anyway this is the kind of stuff that makes our hobby more interesting and it helps to be aware of these things.

[Larry Gibson]

Unique

'SEE' has been described as pressure waves building up, bore constriction due to hang fire (of sorts), or to random powder detonation just because.

The "pressure wave" and "detonation" theories are still unproven. The "bore obstruction" theory is documented and is laboratory reproduced. I have posted the Handloader article documenting such several times.

I also have found the same indications of the onset of a probable SEE in my own psi testing with the 6.5 Swede. Your additioal "possibility" is also quite real in setting up for an SEE. A documented case of such was with a "starting load" of 2400 in a 45-70 case using a 300 gr jacketed bullet. This occured in a Contender that had been throated long for use with 400 gr bullets seated out. The pistol was held muzzle down and simply raised level to fire. Obviously the small charge of 2400 was at the front of the case against the bullet as no filler or wad was used. This set the stage for the force of the primer of the 3rd shot to drive the bullet out of the case and lodge/stick it in the now foulded throat. The powder then began to burn and with the bullet stuck in the throat the psi reached was extreme before the bullet bega to move but the the bullet could not move quick enough and the SEE occured when the psi exceeded the structural strength of the Contender. The Contender was destroyed and fortunately there was only minor injury to the shooter.

I have also observed extreme psi's whn smaller amounts of 2400, H110/296, 4227 and similar powders were prepositioned to th front of the case. This is why the selection of powder for such loads should be based on it's ignition capability in the case selected with the bullet weight selected. "Just because" we already have the powder or the powder is "cheap" are not, many times, a good selection criteria.

Larry Gibson

[303Guy]

The "pressure wave" and "detonation" theories are still unproven. I have seen evidence to support the "pressure wave" theory - reduced load of shotgun powder with filler. Pressure indications were low. The primer looked like no powder was present - not quite though. The case neck locked into rust pitting in the neck area. Normal loads that showed healthy (but moderate) primer flattening did not lock into the rust pitting. That sounds like a "pressure wave" thing.

One of the powder manufacturers had developed a new powder and tested it in a 6.5 Swede test barrel and developed a new factory load. Final testing was done on a military 6.5 Swede and blew it up! It was identified as a SEE and was reproducible. It was to do with the long throat and the bullet moving forward and stopping on the leade IIRC.

Dacron or polyester filler (not quite the same thing) would hardly constitute a wad that would trap gas in front of it nor a piston to ram into the boolit base. 1/2 to 3/4 gr is a lot and would surely fill the case volume?

I've done a fair bit of experimenting with fillers. I'd be cautious with the Swede and would select a filler that flows easily. Dacron would be my first choice. Even the 303 Brit can trap filler behind the shoulder but so far all it's done is leave a ring of filler in the case. It depends on the shoulder angle and Brit shoulder angles are all over the place. The Swede however has a 25° non-included angle which is not all that steep so Dacron should be fine. Not so much the choice of powder. I would not be using 4227 in the Swede.


If it was a double charge, I'd bet a dollar our lucky friend uses loading blocks.I'm not sure how a loading block would result in a double charge - please enlighten me before I blow up a gun.

I have had powderless rounds from not using a block and I've also had double charges from not using a block. Think powder overflowing all over the place as one removes the case from the powder measure (accompanied by appropriate language!) I do try to select powders that fill the case. It costs more as more powder is used plus more lead is used for the heavier boolits required to make the stuff burn consistently.

But I do sometimes use H4227 under a heavy boolit in a Brit with heavy-ish boolits. I do that to raise the pressure and keep velocity moderate. I also use filler - not Dacron but wheat germ (which has some bulk filling properties which Dacron doesn't) and I do so to prevent the possibility of a SEE. So, if I'm treading a perilous path I need to know and soon - before I damage a precious rifle! Or my pretty face.

[swheeler]

I'm not sure how a loading block would result in a double charge - please enlighten me before I blow up a gun.

I have had powderless rounds from not using a block and I've also had double charges from not using a block. Think powder overflowing all over the place as one removes the case from the powder measure (accompanied by appropriate language!) I do try to select powders that fill the case. It costs more as more powder is used plus more lead is used for the heavier boolits required to make the stuff burn consistently.

But I do sometimes use H4227 under a heavy boolit in a Brit with heavy-ish boolits. I do that to raise the pressure and keep velocity moderate. I also use filler - not Dacron but wheat germ (which has some bulk filling properties which Dacron doesn't) and I do so to prevent the possibility of a SEE. So, if I'm treading a perilous path I need to know and soon - before I damage a precious rifle! Or my pretty face. 303 man you are too late!!!!!:):kidding:

[Rocky Raab]

Well, since you asked three times....

People who charge all the cases in a loading block and then "look into every case" risk skipping some cases and/or double-charging others. Humans simply can't do that kind of repetitive action consistently. That's been proven time and again. Worse, the eye can easily be fooled when looking at a loading block of cases. You believe you looked into every one, but your eye can skip over some or get lost - even looking at different cases with each eye. That's also been proven. It's worse with small charges and bottleneck cases.

However, reloaders who handle one case at a time to charge and then immediately seat a bullet eliminate both of those potential hazards.

[w30wcf]

Ball Caster,
Your experience reminds me of a story some 20+ years ago that was written in the "Fouling Shot" the Cast Bullet Association's publication. I don't remember the caliber nor the powder but in that case, the fellow was loading reduced loads with no filler.

After locking the bolt on his rifle he did an investigation and found that at least some of the cases he used had already been charged with powder previously with a tuft of dacron holding it in place.

He did not complete the loading operation at that time then, somehow, got them mixed in with other primed cases. You can imagine what happened. He made some handloads with faster burning powder using no filler and, unknowingly, double charged those cases that were already loaded............

stay safe,
w30wcf

[1Shirt]

Am not a betting man, but if I were, would go for a double charge. With any of the fast powder loads, unless they fill at least half of the case, I weigh the finished ctgs to avoid a double charge on a small digt scale. If there is more than a slight weight variance, I pull the blt, and check. A lesson learned the hard way! I shoot a lot of 2400 in rifles with cast, and in almost all cases use a filler, and have had not problem. Not a recommendation, just my practice and experiance.
1Shirt!

[Larry Gibson]

Larry, is 16 gr of 4227 really that low a charge? And I don't consider a 6.5 x 55 a "large case". I also think the filler would vastly improve ignition of the powder as it is held against the primer.

I still vote for double charge. And I agree with Rocky, a loading block is often a culprit. Never use them any more.

Lyman's current starting load is 17 gr with the 140 gr cast in the 6.5 Swede. Considering that data (#49 Manual) is listed with pressure readings it was tested in a pressure barrel. There is then probably a very good reason for the 17 gr starting load.....more than likely Lyman's technicians found erratic ignition below that.

My vote is on a double charge also.

Larry Gibson

[blackthorn]

I use load blocks! I use two blocks, I prime the cases and place them into a block mouth down. When I start to charge the cases I take one, turn it right side up, add powder and place it into the second loading block. Once I have all the cases charged, I do a visual check using a good light and then start to seat the bullets. Been doing it that way for 45+ years and no double charges or empty cases (yet)!

[swheeler]

The real answer is we will never no why. The answer to that is because the realoader cannot say for certain that he did not double charge a case, use a case too long or tamp the dacron into wad leaving an airspace between wad and boolit base. Now everything mentioned is nothing more than a WAG, live and learn is my motto.:)

[unique]

Now everything mentioned is nothing more than a WAG:)

Well wouldn't be a much of a forum if everyone expressed
Absolutes. I would say most everything we believe starts as a
Guess.


Unique

[303Guy]

... You believe you looked into every one, but your eye can skip over some or get lost - even looking at different cases with each eye. That's also been proven. It's worse with small charges and bottleneck cases. ...

However, reloaders who handle one case at a time to charge and then immediately seat a bullet eliminate both of those potential hazards.Thanks, Rocky. I can relate to that. Once a buddy and I were out on a farm and we saw all these strange plough like cuts all over the grassy hills and could not figure out what they were for. On the return we found a pine tree planted in one such cut, then another and another then realised the whole damn countryside had been planted! But we saw nothing going in. Nicks, zada, zilch! Both of us! It was a scary eye opener. :shock:

But I have done boo boos with handling one case at a time so I would suggest we should all seriously examine our individual preferences and find the one that suites us each the best. I am pretty anal about checking and double checking so I hope I have a safe system for me. But I will think on this and re-examine my practices.

[Rocky Raab]

That's more or less my point, 303guy: we humans can screw up darn near anything. Knowing that, however, some of us can find a way to minimize the chance of making a mistake. The "one round at a time, no load blocks" reloading technique is one such method.

Good for you guys who use load blocks safely - so far. But it's a bit like running blindfolded across the interstate. You can do it successfully any number of times -- until the last time.

[btroj]

I use a method like Rocky mentioned. I have a small bin of primed cases. Dump powder, sera bullet. Repeat. No blocks used at all

[lwknight]

Its already been suggested a few times but I have to affirm the ( forget 4227 in bottle neck cases theory).
Its best served in straight wall cases with heavy bullets.

[brassrat]

I started reloading three yrs ago and had two squibs, at beginning, which I caught ( after firing) lol. I was doing the one at a time method. I have since been using the block method, with no trouble. My bench has a magnifier light which is the only source of light. The mag part of the light is constantly used during reloading and during case inspection. I will look a couple times and no way that I will mess up. I also sometimes charge randomly so am always looking into block. I use the Belding/Mull drop tubes, so the cases are put in the block and stay there.

[44man]

My friend loaded one at a time. Had the case in his hand, his son asked him something so he forgot to charge the case and seated a boolit. It stuck in the bore and the next shot blew the gun.
Use a block and look in every case before seating. I can't make it more clear.

[SlippShodd]

Dagnabit! Read the whole thread and still have to express my igornance. What is the usage of S.E.E. here? Single Event Effect? Standard Error Event? Standard Error of Estimate? Signing Exact English?

mike

[cbrick]

I used loading blocks for a long time but haven't for several years now. Now what I do is use the MTM ammo box as a loading block, I prime the entire lot of brass that I'm going to load, then I charge a case and seat the boolit and put it back into the MTM ammo box. I go through all of them this way and if it's a cartridge that will be crimped I go back through them and crimp.

So far so good. Haven't yet had a Ka-Boom or un-charged case.

Rick

[Rocky Raab]

S.E.E. stands for Secondary Explosion Event and is used to describe what seems to be a genuine explosion in what should be a deflagration of gunpowder. In other words, a KABOOM instead of a bang. It usually is associated with overly reduced charges of slow powder in large-capacity cases, but some folks use the acronym to describe almost any over-pressure event - hence a good deal of confusion.


44man, anecdotal "evidence" works both ways. There are also tales of "a guy who used load blocks and..." If you use a loading block and get distracted during the practice, you are just as likely to have a problem as the guy you described. If you are distracted during reloading, you stop and re-examine what you've done - period. I'll just say it again: Optical illusions are MUCH more likely when looking at a mass of similar items than when looking at only one item.

[dnotarianni]

Time for my 2 cents worth. First shot was fine and second was the problem. First shot went bang and second one had bad or loose crimp causing bullet to move forward in the magazine creating an air space between powder, filler and head and causing detonation in the chamber from too light a load in too big a case. I don't believe a double charge as 16 vs 32 grains I don't believe would fit in the case.

Dave

[Larry Gibson]

The term "S.E.E. stands for Secondary Explosion Event " was coined well before it was understood proven in a lab by ballisticians what actually causes it. It is not a "deflageration" or "explosion" of the powder. It is indeed a very high pressure event caused when the bullet becomes stuck, or momentarily stuck, in the throat. As noted in the above post and in the lab tests it is after one or more shots that the event most often occurs as the throat becomes fouled. Fouling of the throat is more common with reduced loads because the powders are not burning clean and the primer residue (small grit particals) are not blown out thus the bullet gets stuck in the throat (a rough eroded throat exasperates the problem, especially a long throat or a free bored throat).

The results of the SEE from the bullet momentarily sticking in the throat are identical to an actual bore obstruction ahead of the bullet. The results are also the same as if we overload (as in a double charge in this instance) the cartridge......damge, many times total, to the firearm is the result.

We know the cause of SEE as we can readily reproduce it in the lab and on the range. Why we keep theorizing and bringing up the old unproven and wrong theories is beyond me..........

Larry Gibson

[blackthorn]

So---Anyone going to comment on the article in the December issue of "Hanloader" Page 46 by Terry Wieland titled "Chamber Pressure Revelations"??

[44man]

Larry has it right. It is not detonation but rather a reversal of pressure from a stopped bullet no matter how short. Even a "stutter" is bad. The bullet becomes a bore obstruction plain and simple.
A double charge usually blows the gun but most S.E.E events do not destroy the gun, just the brass. You know which is which by the primer. If the pocket is enlarged it is an S.E.E. but if just flat, it is too much pressure from the load.
Of course you can have all kinds of destruction from each.
With the S.E.E events I have seen, the primer was not even found, brass is destroyed and bolts need driven open. Yet measurements showed no rifle damage and they are still shooting.
An observation that you do not take to the bank, just my opinion.
I have always wondered how many S.E.E events happen with revolvers every day with no case tension, high pressure primers, soft lead, etc and the cylinder gap is saving everyone?

[shooter93]

Might want to call them minor SEE events in a revolver 44man. Recently Mic McPherson noted that identical very safe loads when shot in a revolver showed greater pressures than the same load fired in a closed chamber....a 44 mag in this case. In his research he talked to the Casull people who told him they discovered it yrs ago when developing the 454. And the Speer people concurred (one of their ballisticians mentioned the same thing to me in a conversation I had with them in the early 70's) telling him they saw such a drastic rise in pressures from the stutter you describe when the bullet actually paused when striking the forcing cone that they redesigned their jackets. It would be greater with jacketed as opposed to cast but it does happen. Charlie Dell did a lot of research into ringed chambers, bulged barrels etc and makes a very credible theory. I'm not sure how to reference his paper as I have it in one of his books but it is a very interesting read.
As far as using loading blocks or not.....either way has caused accidents. The safest way is the way you feel most comfortable using and practice the utmost safty when using it. We are human and we are flawed....we will make mistakes and shooting/reloading are very serious proposistions. In my life I have probably seen the results of atleast a 100 catastrophic failures. Some we could pretty wll figure out what happened while others were like the one mention in the first post....we'll probably never really know. The vast majority rsulted in no serious injuries while others were devastating.

[Bullwolf]

For checking light charges of fast powders in bottle neck cases, go to Wally World and pick up a tire gauge with a square reader stem. Remove reader stem and drop it into charged cases. Light charges, heavy charges and double charges show up instantly. Infinitely better than a flashlight.

Took me a while to remember where I had first seen this tip, so I could give credit to the original author.

It was on Page 8 of the Share Your Tip Of the Day sticky.
http://castboolits.gunloads.com/showthread.php?110506-Share-Your-Tip-Of-The-Day&p=1440990&viewfull=1#post1440990

Go out and buy, or disassemble an existing tire pressure gauge much like this one.

http://www.atvconnection.com/Departments/ATV_Tech/images/tire_pressure_gauge.jpg

You have probably already thrown away one that was lurking in the bottom of a dirty bucket of wheel weights.

Pull out the measuring stick inside.

http://static.ddmcdn.com/gif/pg-parts.jpg
You can use the gauge to easily check the depth of powder charges that are difficult to visually inspect.
(for example: inside small caliber bottle neck rifle cases)

This gives you a compact numerically scaled powder check gauge. It's even handy for double checking straight wall pistol and rifle case powder charges that don't look quite right. It's not fool proof, but it's handy if you don't quite trust what you see even when using a good light.

This is another step you can take to help prevent a squib load, or an overcharge. Do this with every powder charge that you throw, and it will become readily apparent if there is a problem with your powder measure.

When a powder charge looks suspicious on the stick, pour it out and re-weigh it. Check and double check to help eliminate any squib loads, under charges, overcharges, or double charges.

If you must load with a progressive press, try to make sure that you can see each powder charge. A very bright light also helps with this, as well as using a powder cop die.

There is always going to be the basic probability of human error, but if you are vigilant you can curtail many potential problems by simply practicing smart reloading habits.



- Bullwolf

[Tao77]

I use load blocks! I use two blocks, I prime the cases and place them into a block mouth down. When I start to charge the cases I take one, turn it right side up, add powder and place it into the second loading block. Once I have all the cases charged, I do a visual check using a good light and then start to seat the bullets. Been doing it that way for 45+ years and no double charges or empty cases (yet)!
+1 IMHO it's right path.

[Larry Gibson]

So---Anyone going to comment on the article in the December issue of "Hanloader" Page 46 by Terry Wieland titled "Chamber Pressure Revelations"??

I will comment on it; a very poor article. Talks about SEE, restates the "wave detonation" theory of 40+ years ago then goes on to discus the articles/book by Dr. Brownell regards to how overloads cause high psi (like duh!) in a comparison of the 280 Rem to the 284 Win. The "pressure excursions" were mentioned as happening in large capacity magnums with slow burning powders using jacketed bullets yet the picture shows a standard cartridge with a cast bullet an low density charge of faster burning powder(?). Wieland mentions leaving his 257 Weatherby ammo in the hot sun and having pressure problems (again like duh!) which has nothing to do with the subject of SEE or even the "wave theory" for that matter. All in the article leading the unknowledgable reader to believe the "wave theory" is correct. Again, a very poor article and very disappointing.

Most of us who paid attention "back in the day" will remember SEEs started with the 25-06 and the 257 Weatherby with an occasional .270 thrown in. All were reloaded with reduced loads of surplus 4831 and light for caliber jacketed bullets. What causes SEE is proven, documented and reproducable. It has nothing to do with the so called "wave theory". Wielands article is misleading at best and *&%$*** at worst. Ask me what I really think of it sometime..............

Larry Gibson

What is even worse about the article is absolutely no mention of the Handloader article that showed what really causes an SEE by either the author, Terry Wieland, or even and inserted note by the editors of Handloader referring to that Handloader article! Absolutely amazing!!!!!

[popper]

What causes SEE is proven, documented and reproducable. It has nothing to do with the so called "wave theory"
Not sure I can agree with you there Larry. After watching many, many hours of DOD H.S. movies of propellant explosions, classified as S.E.E or 'uncontrolled' burn rate, my conclusion is that extreme pressure spikes break things. As you have stated, powder burn rate is a function of pressure. Pressure wave generated by burning also has a rate and position. Yes, a stuck bullet (even temporary) will cause pressure spikes. So does lighting both ends of a 'candle'. And pushing an improperly spaced wad into the back of the bullet. Best case is a 100% load burning from primer forward to the base. Anything else is a WAG.

[unique]

We know the cause of SEE as we can readily reproduce it in the lab and on the range. Why we keep theorizing and bringing up the old unproven and wrong theories is beyond me..........
Larry Gibson

Whoa there friend. That's like saying the only way to wreck a car is to hit a telephone pole. Putting the definition of 'SEE' aside for now, I suspect that the the cause in this case was as you described, a bullet acting as obstruction leading to higher than normal pressures.

However, that doesn't mean wave theory 'crashes' never occur. I am sure they do as resonance waves in the chamber. Just doesn't happen that often. Using the term 'SEE' is like using the term car crash.

So when my wife comes home and says she wrecked the car I always ask, anyone hurt, how bad is the damage, and what caused it. Same thing applies here although nine crashes later I think the real cause isn't a great mystery.

Unique

[Larry Gibson]

popper and Unique

The "wave" and the "powder detonation" theories have yet to be proven despite the best efforts of many ballisticians. What causes SEE and the factors involved are known, have been known for about 30 years now and can easily be proven (if either of you would care to donate a M96 6.5 Swede I will take it to destruction with an SEE and show you the documented pressures. Will do it with you or other witnesses present.). That the theories are stated over and over again and regurgitated often does not make them fact. My comments of such as you've quoted stand in reference to the article in Handloader and it remains a poorly written and constructed article. That article in Handloader did nothing to substantiate either the wave theory or SEE, it only regurgitated the wave theory leading the unsuspecting to think it was THE cause of SEE.

In the instance under discusion in this thread I have stated it was either from an SEE (caused by a bore obstruction as most all the classic indicators of an SEE are there) or more lkely from a double charge of powder. A double charge of powder put into a case (if possible) is a far more common place error that is an actual SEE occurence.

Larry Gibson

[swheeler]

I will comment on it; a very poor article. Talks about SEE, restates the "wave detonation" theory of 40+ years ago then goes on to discus the articles/book by Dr. Brownell regards to how overloads cause high psi (like duh!) in a comparison of the 280 Rem to the 284 Win. The "pressure excursions" were mentioned as happening in large capacity magnums with slow burning powders using jacketed bullets yet the picture shows a standard cartridge with a cast bullet an low density charge of faster burning powder(?). Wieland mentions leaving his 257 Weatherby ammo in the hot sun and having pressure problems (again like duh!) which has nothing to do with the subject of SEE or even the "wave theory" for that matter. All in the article leading the unknowledgable reader to believe the "wave theory" is correct. Again, a very poor article and very disappointing.

Most of us who paid attention "back in the day" will remember SEEs started with the 25-06 and the 257 Weatherby with an occasional .270 thrown in. All were reloaded with reduced loads of surplus 4831 and light for caliber jacketed bullets. What causes SEE is proven, documented and reproducable. It has nothing to do with the so called "wave theory". Wielands article is misleading at best and *&%$*** at worst. Ask me what I really think of it sometime..............

Larry Gibson

What is even worse about the article is absolutely no mention of the Handloader article that showed what really causes an SEE by either the author, Terry Wieland, or even and inserted note by the editors of Handloader referring to that Handloader article! Absolutely amazing!!!!!

Ah yes 1971 for me, friend came back from elk hunt with biggest shiner and scratched up face I'd seen in a while. When teasing Dale about who had cleaned his clock, he told me his Weatherby had blown up, a 300 shooting 180's and starting charge of 4831 had splintered the stock and spit the barrel out on the ground. In our wisdom we all decided it was a barrel plugged with snow. Fast forward to 1993, shooting a 35 Whelen with a WAG starting load of IMR4227, 25 grs under a 200 gr boolit. First shot delayed ignition, never experienced a click bang except in my 50 ML-what the hay-it's all good, second shot WOW! Pounded bolt open and ejected a belted case, had a primer as big as that of a 50BMG, everthing held-God watch out for fools and children. Still have the 35W and still shoot it, but it will get rebarreled some day soon. No permant deformation of metal that I can tell but a little more cautious these days, no more of the who cares you got ten fingers and two eyes. Since then I've learned a MINIMUM load is there for a reason, fillers and how to correctly use them, and three powders(two never with filler or not-1 I will use but only with a filler) that are not FOR ME in reduced loads in bottle necked cases(funny what you can learn with a chrony and some common sense), I've made it this long with all my fingers and both eyes, no kabooms in 49 years of reloading. Funniest thing, in 19 years of trying to find out about pressure excursions and total wipe outs about 90% involve one powde, I'll let you guess which one. So I have to say I agree with Larry until it comes to IMR4227 powder, I have my own ideas but someone smarter than I will have to come up with the answer, probably one of our "powder gurus" on here. Survivor:)

[unique]

Larry,

I like all my Swedes and will pass on your offer to blow one of them up. There is no doubt in my mind that your version of 'SEE' exists and can be produced at will. However, you must realize just because you haven't seen proof of wave theories or detonation doesn't mean it can't exist.

Here is something to try that doesn't involve blowing up an innocent Swede. Put 10 grains or so of Bullseye on a solid metal surface and smack it really hard with hammer and see what happens but make sure you wear earmuffs and safety glasses because I am pretty certain it will detonate... at least it has every time I tried it.

Unique

[popper]

wave theory leading the unsuspecting to think it was THE cause of SEE I don't state the 'wave' causes the secondary burn, but that the secondary burn causes a pressure spike which causes the damage. I also don't believe the wave can bounce off the exiting projectile and cause a pressure spike. I do believe that a layer of powder on the bottom of the case can ignite at 2 separate points and cause a pressure spike. Not a ballistician but I do believe evidence from naval ordinance personnel working on rocket motors in the 50s & 60's. Yes, they even had propellant plugging the orifice too. They had plenty of SEE to observe, some of the film was of internal SEE.

[swheeler]

I don't state the 'wave' causes the secondary burn, but that the secondary burn causes a pressure spike which causes the damage. I also don't believe the wave can bounce off the exiting projectile and cause a pressure spike. I do believe that a layer of powder on the bottom of the case can ignite at 2 separate points and cause a pressure spike. Not a ballistician but I do believe evidence from naval ordinance personnel working on rocket motors in the 50s & 60's. Yes, they even had propellant plugging the orifice too. They had plenty of SEE to observe, some of the film was of internal SEE.

Oh yes I believe it is far more complicated than us mortals can comprehend, that's why we have the sage advice of our internet gurus, otherwise where would we gain our knowledge, gun wrags????

[303Guy]

Put 10 grains or so of Bullseye on a solid metal surface and smack it really hard with hammer and see what happens but make sure you wear earmuffs and safety glasses because I am pretty certain it will detonate... at least it has every time I tried it. That made me sit up and take notice!

I do think pressure waves exist but am not sure they cause SEE's. I just don't know. (I have evidence of pressure waves - not proof). I do think that where there's smoke there's fire - or smoldering. Usually.

[swheeler]

That made me sit up and take notice!

I do think pressure waves exist but am not sure they cause SEE's. I just don't know. (I have evidence of pressure waves - not proof). I do think that where there's smoke there's fire - or smoldering. Usually.

I do think that is sound thinking, unless you want to post on here "I had a KaBOOM" I cannot express the hundreds of people that have related to me of having hangfires/delayed ign and continued shooting, some people are just lucky I guess? I consider a hangfire as warning!, you are about to screw the pooch. But enough of this hype, load whaT YOU WILL AND ENJOY, I'll reaD IT IN THE FUNNIES. Good night and good luck

[Larry Gibson]

Larry,

I like all my Swedes and will pass on your offer to blow one of them up. There is no doubt in my mind that your version of 'SEE' exists and can be produced at will. However, you must realize just because you haven't seen proof of wave theories or detonation doesn't mean it can't exist.

Here is something to try that doesn't involve blowing up an innocent Swede. Put 10 grains or so of Bullseye on a solid metal surface and smack it really hard with hammer and see what happens but make sure you wear earmuffs and safety glasses because I am pretty certain it will detonate... at least it has every time I tried it.

Unique

That's ok, no one else has taken me up on producing an SEE in a Swede or any other rifle either. No, we have not seen any proof that the "wave theory" exists in cartridges as under discussion. Other than regurgitated in magazines, books and internet posts there has not been one single piece of evidence to support any specific cause of a "wave" detonation of the powder in cartridges. Thus I'm not saying it idoes not exist just that there is not a single shread of evidence that it does nor can it be reproduced.

To the contrary we know what the causes of SEE's are (a bore obstruction caused by the bullet sticking in the throat before the powder burns sufficiently enough to keep it moving) because there is lots of evidence obtained over the years and it can be reproduced/proven. In every reported incident of an SEE most all of those causes are present. The evidence from the destroyed firearms is there in this case also. What is confusing many times though is the end result of an SEE is almost identicle to a double or over charge of powder (if the double charge produces sufficient psi for firearm destruction.....many "double charges" are still safe loads though). What we should also note is that the end result is exactly the same as if an actual bore obstruction was in the barrel; the same type of destruction is present in all 3 cases.

Sorry but I don't really see pressure caused through sudden compression, heat generation and friction as consistent with the discusion of a pressure "wave". I will try to keep from loading my hammers in cases with my Bullseye loads based on your example though:bigsmyl2:. By the way; I have fired many, many reduced loads and have measured the velocity AND the psi of many of them. Powders do burn differently at reduced psi (extremely high psi also). Thus a powder "smoldering" (as mentioned) can move the bullet into a roughened and fouled throat where the bullet sticks. The powder then begins to burn and since powders burn very quickly they can reach max psi before the bullet starts moving again. The result can be a hang fire or an SEE. As swheeler mentions; I consider a hangfire as warning!, you are about to screw the pooch. Probably a good idea to heed that warning.

Larry Gibson

The original question here was about the article in Handloader, not whether or not the "wave theory" exists. My comments are directed to the article which regurgitates the "wave theory" and suggests it is the cause of SEE but then gives no substantiation of that ascertion in the article. That is "problem" I addressed in my comments regarding thearticle.

[popper]

Rocky Raab Not an argument - just a definition and the only one I can find.
"(...) is a phenomenon known as Secondary Explosive Effect (SEE).(...) SEE is the result of slow or incomplete ignition of small amounts of smokeless powder. The powder smolders and releases explosive gases which, when finally ignited, detonate in a high order explosion. ". Using the universal gas law - P,V,T - who cares if it is pressure or temp causing the gas ignition. It is dieseling! So combustible gas that re-ignites causes an extreme pressure spike. We know the burn rate of gas is much higher than a liquid or powder. So, slow, partially decomposed (old) powder @ low load density = possibility of S.E.E. In reality, anything that allows a faster than spec. burn rate will cause the pressure spike.

[303Guy]

Deiseling? That's a thought. If that were to occure then a pressure was could well be set up. But I would think a pressure wave would produce symptoms of detonation rather than extreme pressure. A small charge of fast burning powder might set up a pressure wave which might exibit a higher pressure in one portion of the chamber than another. This is what I'm seeing - or what appears to be. It looks like the beginning of chamber ringing.

[44man]

Hard to respond but my belief is gas formed from burning powder can no longer burn as oxygen is used up. Closed container and only powder creates it's own oxygen. That is limited. I do not believe in detonation either with smokeless.
Pressure wave? don't know but what if the pressure is reversed to the case head instead of pushing a bullet?
Just different then too much powder that creates too much pressure. Blown guns from each will show pressures at a different place on the brass and steel with over pressure leaving the primer and pocket looking normal.
S.E.E has more affect at the back of the brass.