Light loads and SEE?

[andym79]

I guys I am looking to develop a plinking/50 yard target load for .30-30 with a 165grn RNFP cast bullet! I apologize for asking silly questions like this but, do Red Dot, Green Dot, Blue Dot, Bullseye, 2400, H4227 or unique pose a risk of Secondary Explosive Effect in very light loads? Are they position sensitive? Do you think a squib is much more likely than SEE?

I refer to loads of loads like this Red dot 5.5grns 170grn RNFP .30-30 between 1000 - 1150fps!
Green Dot as above 6grns, Blue Dot as above 8.0grns!
Bullseye " 5.5grns
2400 " 8grns
H4227 " 10grns
Unique " 9grns

I am petrified of SEE!

After a little research into burn rates and density, Blue Dot, 2400, 4227, H4198 and H48955 don't seem so great as subsonic loads!

Where as International, Unique and Universal would appear better suited, but not ideal, having significantly slower burn rates than these powders:

5. Alliant Bullseye 9.398
8 Alliant Red Dot 7.077
14 Hodgdon Clays 6.8408
18 Trailboss 3.046
25 Alliant Green Dot 7.924

With the exception of Bullseye, All of these powder are bulky, Trailboss especially so. I find myself thinking that Trailboss and Red Dot, and possibly Clays, are probably the best choices!

Opinions?

[felix]

A wad of dacron is your friend with the bigger grained powder. Shotgun plastic ball filler over small or flat grained powder to barely touch boolit base is as well. ... felix

[sisiphunter]

Trail boss sounds.like a good option for ya...it gives light loads and you cannot double charge. Read the imr website...if i remember right it needs 75% case volume+ to work. I loaded up some.30-30 a few yrs ago with 160gr casts and they shot great to 50yds. They are fairly light tho but thats what it is meant for.

Unique is a good choice.as well...i use alot of unique. Just follow the load books and you will be fine.

[geargnasher]

Stick with book loads of Unique or Red Dot and you'll be fine. Probably won't need a filler of any sort with those, but a grain or less of Dacron poked down in the case and lofted up to fill the space between powder and boolit base will virtually guarantee complete initial ignition.

Personally I'd use Unique and scrub the filler because it hasn't shown any difference in my .30-30s, although it makes a BIG difference with 2400.

Gear

[quilbilly]

I have really enjoyed using 5744 with my Lee 160 gr. in the 30/30. Took it all the way down to subsonic and it shot fine but went back up to 15 gr at 1550 fps because of versatility. That light load is fun to shoot all day, accurate out to 300 yds and beyond, and the recoil is so light my wife enjoys it.

[**oneshot**]

I prefer bulky powders like 4759 and trailboss. They make light loads easy, and SEE will never come into play.

[3006guns]

First of all, I was under the impression that SEE only came into effect when using SLOW burning rifle powders in small amounts, not the faster burning powders listed.

Secondly, SEE was finally diagnosed as a bore blockage caused by the slow powder igniting, moving the boolit, boolit stops at throat for an instant as the remainder of the slow powder burns and is unable to escape due to the momentarily lodged boolit. Pressure spikes. Boom.

All of this from a thread some time back which finally diagnosed the problem thats baffled reloaders for years. About the only problem you'd have with the faster powders is position sensitivity, which can be solved by either lowering the firearm slowly before firing or using a tuft of Dacron. 2400 does not seem to be sensitive in this regard and Trail Boss fills the cases so well it's not an issue.

Just stick to the book load info and you should be fine. Just remember, no SLOW powders in small amounts.

[Bret4207]

You are looking at easily ignited. fairly fast burning powders in a relatively small case. SEE shouldn't be a factor at all. Double charges, maybe, but not SEE.

[1Shirt]

listen to Gear and Bret. I agree with them and their comments. Also thing you could not go wrong with trail boss for what you are looking for as 50 yd plinking loads. Good luck!
1Shirt!:coffee:

[lylejb]

I've used 8.5 to 10 grs of unique in 30-30 with a 31041 173gr and with the lee 150gr fp, without any problems.

I don't use filler. I've used various LR and LP primers, doesn't seem to matter, all worked fine.

I've also used 9 to 11 gr herco, with the same boolits, and the same results.

These are good fun/ inexpensive / plinker loads.

I've never achieved what I would call "target" accuracy with these. I get 2" to 3" at 50 yds, but I'm working on that.

My purpose for these is a fun load for my son to plink with, and the're just right for that.

[williamwaco]

I've used 8.5 to 10 grs of unique in 30-30 with a 31041 173gr and with the lee 150gr fp, without any problems.

I don't use filler. I've used various LR and LP primers, doesn't seem to matter, all worked fine.

I've also used 9 to 11 gr herco, with the same boolits, and the same results.

These are good fun/ inexpensive / plinker loads.

I've never achieved what I would call "target" accuracy with these. I get 2" to 3" at 50 yds, but I'm working on that.

My purpose for these is a fun load for my son to plink with, and the're just right for that.


Ditto.

8 to 10 grains of Unique is just about a universal cast bullet load in almost any rifle. I have used it in the .30-30 and the .38-55 with bullets from 150 to 250 grains. It is very accurate in every thing I have tried it in. I get 1.0" to 2.5" at 100 yards with either caliber. Velocities are moderate and so is recoil.

( We will get some disagreement here - ) It is totally position independent and needs no filler.

Try it - You will like it!



.

[geargnasher]

I have never found a load in any cartridge so far using Unique that showed any benefit from filler. There are probably proven exceptions like with just about anything, but I'm just sharing my experience.

Gear

[andym79]

8 to 10 grains of Unique is just about a universal cast bullet load in almost any rifle. I have used it in the .30-30 and the .38-55 with bullets from 150 to 250 grains.

From Lyman manual I have between 7 and 10.6grns for a .30-30 but 12 to 16 for a .30-06!

[Mavrick]

When using one of the double-base shotgun powders, you'll find ALMOST no position sensitivity. They're just too easy to ignite. As has been said, if you load way slow, in the sub-1000fps range, you will benefit using a filler. My preference, FWIW, is Dacron.
The quicker single-base powders, like IMR 4227 or 4198, maybe show some sensitivity.
I wouldn't worry about SEE except in your .244 H&H Magnum...You DO have one, right? Even then, if you're not loading to 1500fps with IMR 4831 or 7828, I wouldn't worry!
Have fun,
Gene

[zuke]

Use Trailboss and there's absolutely no way for a double charge to happen.
It would overfill the case and dump all over the bench.

[Jeffrey]

My 30-30 cat sneeze load for back yard shooting here in rural south mississippi is 3.5gr bullseye under a 150 gr LFN lubed with Johnson paste wax. Sweet. Sounds like a .22, hits like a .38. See http://castboolits.gunloads.com/showthread.php?t=94463 for a few more details. Jeffrey

[jdgabbard]

Here are two threads of interest. I reference them often.

10 Grs. Unique. The Universal Cast Boolit Rifle Load? (http://castboolits.gunloads.com/showthread.php?t=39923&highlight=unique+rifles)

Cast Bullet Loads for Military Rifles - Article (http://castboolits.gunloads.com/showthread.php?t=13425&highlight=unique+rifles)

They are of particular interest, and highlight the comments above about the 10grs of unique being the universal load.

[andym79]

My 30-30 cat sneeze load for back yard shooting here in rural south mississippi is 3.5gr bullseye under a 150 gr LFN lubed with Johnson paste wax. Sweet. Sounds like a .22, hits like a .38. See http://castboolits.gunloads.com/showthread.php?t=94463 for a few more details. Jeffrey

Thats good!

Really that light a load, a couple of questions!
1. Do you have any idea how many fps I am guessing 800!
2. How many such rounds have you fired!
4. Also did you use any filler, if not did you lift the round up before firing?
3. The 5/8" group is that bench?

Data here http://www.gmdr.com/lever/lowveldata.htm here has a 5grn load behind a 170gr bullet at 990fps!

[Centaur 1]

I've tried a few different powders and I keep going back to Trail Boss. I haven't shot them yet, but my latest experiment is with a 94 grain .32 S&W boolit over 7 grains of Trail Boss in 30-30. It should be a good round for rabid armadillos and zombie squirrels. :Fire:

[mdr8088]

The Lyman manual has some Unique loads you should look at. I use a small amount of poly in them.

[aussie rich]

Hey andym79

Trail Boss was designed for safe low velocity loads, and can be quite accurate to boot. I use it a lot in my 45-70, but you can use it in just about anything to produce a plinking round. The winner of this and last years postal match on Marlin Owners forum used TB for some great results.:drinks:

I haven't used Unique myself, expensive and hard to get over here, and I don't wish to start a war, but according to the internet TB burns a lot cleaner than Unique, though I would like to hear from people who have used both to clarify the point.

Whichever powder you use the best way to keep your hands and eyes where they should be is to stay within published data from a reputable source. The Lyman reloading manuals have low velocity loads for most calibers, and in my humble opinion generally make a good read too.

Also the Australian Defense Industries (ADI) smokeless powder handbook is available free from their website, I'm pretty sure ADI make TB for Hodgen/IMR to sell the States and they have a TB load in their manual for pretty much every caliber you can think of.

Good luck with your loads

Rich

[Jeffrey]

Thats good!

Really that light a load, a couple of questions!
1. Do you have any idea how many fps I am guessing 800!
2. How many such rounds have you fired!
4. Also did you use any filler, if not did you lift the round up before firing?
3. The 5/8" group is that bench?

Data here http://www.gmdr.com/lever/lowveldata.htm here has a 5grn load behind a 170gr bullet at 990fps!

1. FPS?... No idea. Do not have a chrony.
2. More than 20, less than 50.
3. No filler. For paper punching rifle was moved barrel up before firing. I've had a 'shoot, shovel, shut up' situation where the rifle was pointing at a downward angle.
4. Measured group was from 'bench'. Or more specifically picnic table, while resting on flotation vest.

Rifle is Marlin microgroove 336.

[uscra112]

Red Dot was Ed Harris' go-to for very light loads in almost everything. I finally bought a jug of it, and I now see why.

As has already been said, SEE is not a phenomenon of light loads and fast powders. It was BLAMED many a time in cases where a double charge was the real culprit, until researchers were able to reproduce SEE in the laboratory.

[BOOM BOOM]

HI,
With the pistol powders I have shot many 1,000 of rounds in my 7MM/06 & 7MM MAG. with no problem. Just use book suggestions & you will not go wrong.:Fire::Fire:
The SEE problem occurs when reduced rifle powders are used W/O a filler.

[noylj]

What is SEE?
Secondary Explosive Effect?
Is this the mythical "I blew up my gun with a light load of a slow powder" excuse to not admit that you may have used too much powder or the wrong powder?
Any time you work down in velocity, you go to faster powders. Otherwise, the "normal" result is a barrel and action filled with unburnt powder "gunk."
I have read too much about "ringing" barrels to ever want to add fillers to my cast bullet loads in rifles.

[uscra112]

I can see that the Handloader article on SEE needs to be reposted. Thanks to Larry Gibson for having posted it in the first place...

There's a graphic in the article that did not carry through to this post, so it's probably worth hunting up the original article in the Handloader archives.

Mystery Solved


Handloader- readers have doubtless heard of a term called secondary explosion effect (S.E.E.). It is a theory that attempts to explain the catastrophic failure of some rifles while firing seemingly reasonable handloads or reduced loads using slow-burning powders. Theories have been offered and debated in these pages and elsewhere, but they have been just that, theories, because no one has been able to reproduce effects under laboratory conditions. The purpose here is not to debate S.E.E. but rather to report on a specific incident and the results of tests done to discover the cause of catastrophic failure.

One of the great problems with attempting to theorize on the cause of catastrophic failures is that we must do so after the fact. We have the corpse, usually with some parts missing and must try to figure out what went wrong. Learned theories are offered, sometimes conflicting, and we end up with a bunch of folks shouting in print, 'You're wrong.' "No, you’re wrong." Since the event they're arguing about what without benefit of instrumentation, either one could be right. The events I describe here represent the first instance of an event produced under controlled laboratory conditions and documented on industry standard pressure measuring equipment that provides a plausible explanation offered to explain S.E.E.

The following is simple. It goes all the way back to Shooting 101 where we learned that bore obstructions blow up guns. There are no explosions, no mysterious wave amplifications; it's just a case of several factors, combining in worst case conditions to create a bore obstruction with the bullet.

In early 1989 a major manufacturer began development of a load for the 6.5x55mm Swedish that was to be added to their product line. Development was uneventful and all work was done using the copper crusher pressure measuring system, for there were no standards established for piezo-electric pressure measurement in the 6.5x55mm. The copper crusher method of pressure measurement has been with us for generations, but it is not without its limitations. The results obtained are not true "maximum" pressures, and it provides only a single data point. There is no way that one can deduce what is happening during the period the powder is burning, nor can one see other significant ballistic events.

A quantity of ammunition was loaded using a relatively slow-burning, non-canister propellant with a 140-grain bullet. After load development in ammunition manufacturer’s pressure guns, it is common practice to function test ammunition in a variety of available rifles to ensure satisfactory performance before it is released for sale to the public.

As function testing of the 6.5x55mm ammunition was begun using Swedish Mauser rifles, they noticed some of the same signs of excess pressure every handloader is taught to look for - flattened primers, enlarged primer pockets and heavy bolt lift. All the ammunition fired in the pressure gun had been perfectly acceptable, but SAAMI test barrels and chambers are made to tightly controlled specifications so the first supposition was that some element within the test gun was contributing to high pressures. Then a "spontaneous disassembly" occurred that destroyed the action but left the barrel undamaged. The bore was clear and showed no bulges. It was immediately identified as a high pressures failure and an investigation was begun. The barrel from the wrecked Mauser action was fitted with a collar that allowed it to be mounted in a universal receiver, and an industry standard conformal piezoelectric transducer was installed. Another test was performed using the Oehler Model 82 piezoelectric pressure measuring system equipped with a trace hold oscilloscope.

(Fig !)
round pressure (psi) velocity (fps)
1 48,820 2,601
2 53,849 2,662
3 57,609 2,708
4 57,999 2,720
5 54,093 2,687
6 58,634 2,731
7 62,150 2,754
8 82,120 2,875

Pressure tests are commonly done with a 10-round string and as you can see from the chart, pressures increased very gradually on rounds I through 4. At the fifth shot, pressure dropped and then continued to increase until, at the eighth shot, pressure, went to 82,120 psi; and the technician wisely stopped the test. The raw data was then used to prepare additional graphs (fig. 1) which show that, after ignition, pressures dropped momentarily to near zero on the graph before beginning to rise again.

To interpret this data we have to first understand the ground rules applicable to pressure testing with conformal transducers. The key term here is 'offset" which relates, primarily, to the specific cartridge and the brass used therein and must be determined for each transducer and lot of brass. The offset is the amount of pressure required to obturate the case to the chamber and begin to exert pressure upon the transducer. In this case the offset was 3,800 psi so when we look at the time/pressure curves produced in the test; we must understand that we are not actually seeing pressures below the level of the offset. There is a distinct dip in the curve, however, shortly after the pressure begins to rise when it drops to a level somewhere at or below the offset pressure. All we can say for sure is that, at this point, the pressure is <3,800 psi. Engineers calculated that for the specific bullet being used it would take pressure of at least 5,000 psi just to keep the bullet moving.

As I said, there are a number of variables at work here, but the main culprit is a very long leade or throat erosion. It takes relatively little pressure to eject the bullet from the cartridge case (de-bullet), which produces a significant increase in volume. Unless the rate of gas production is fast enough to keep up with the increase in volume, pressure must drop. The simple equation is PIVI=P2V' where P = pressure and V = volume. It is helpful in considering the phenomena reported here to view the rifle barrel and chamber as a cylinder whose volume is determined by the position of the bullet at any given point in time. If the bullet is moving, the volume is continuously increasing until the bullet exits the barrel.

If P2 is at or below the pressure required to keep the bullet moving it must stop. Then we run into our old friend inertia. Bodies at rest tend to remain at rest, but all the powder burning behind the resting bullet doesn't know about that. It keeps burning and pressure rises. Sometimes we get lucky and the bullet starts to move and relieve some of that pressure, but in a worst case of a rough bore and/or soft bullet it doesn't, and pressure continues to build until something else lets go. Most of the time this will occur around the primer pocket and gas will be released through the flash hole, but we're talking about events that are taking place quickly (milliseconds); and if pressure rises at a rate faster than it is being relieved, a catastrophic failure is inevitable It has been theorized that many 'accidents" represent a combination of effects which combine, in worst case conditions, to produce a catastrophic failure. Robert Greenleaf (Rifle No. 146) presents convincing evidence to show that conditions rarely remain the same, and the condition of the barrel and throat combined with different bullet characteristics can produce markedly different pressure levels for the same load. This is certainly seen in this data where a series of eight shots of the same ammunition delivered pressures ranging, and steadily increasing, from 48,820 psi up to 82,120 psi, at which point the test was stopped. We can, from looking at this test data, presume that all rounds (except perhaps the first) displayed some degree of temporary bore obstruction, but that the bullet was blown out of the barrel. Fortunately universal receivers are capable of containing considerable pressures, and it is certainly possible that the pressure generated by the last shot would have wrecked a standard rifle.

One factor that cannot be accurately measured with this data is the possible contribution of fouling from the bullet itself. It seems reasonable to assume that some accumulated fouling was blown out on the fourth shot, which accounts for the drop in pressure at shot No. 5.

When the engineers were able to examine and expand the time/pressure curves produced during this test, it became obvious that each shot showed a pronounced drop in pressure very early in the ignition/burning cycle and, on the shot where the pressure reached 82,120 psi, it dropped to the baseline before resuming a climb to the stratosphere. It would be easy to think that the fire went out, but a more reasonable explanation is that the burning rate of the powder became even slower. We know that pressure is a major component of the burning rate of any powder, and it depends upon adequate pressure levels being reached and maintained. In fact, what is shown in this case is that the amount of gas being generated was not sufficient to keep the bullet moving. If pressures drop below some optimum level, burning slows down and is often incomplete. Of course there will always be a quantity of unburned powder from any shot, and this observation has led to some of the conclusions regarding S.E.E.

In order for the pressure to rise to catastrophic proportions some other adverse conditions must also be present. These involve the cartridge case, the bullet, chamber and barrel and need to be discussed individually.

Bullet pull: We know that an adequate amount of tension between the case neck and bullet is a prerequisite for uniform combustion. This term, called bullet pull, is independent of the firearm and is routinely measured in the factories. Crimps may or may not be used to increase bullet pull, but most centerfire rifle cartridges depend primarily on tension between the case and bullet. If you've ever committed the sin of firing a cartridge into which you have neglected to dispense powder, you know that the primer alone is perfectly capable of propelling the bullet several inches down the barrel. Pressure generated by a primer alone can be as much as 4,000 psi in a conventional centerfire rifle cartridge; so it is certainly possible, in a normal round, for the primer impulse alone to be sufficient to get the bullet moving before little if any pressure has been generated by the powder charge.

Chamber: In the area of the case neck there must always be some clearance between the case and the chamber wall, but if this area is too large there is little resistance and the bullet can be released with very little pres sure behind it.

Condition of the barrel and throat: The impact of conditions within the chamber and throat are difficult for the handloader to analyze, and a throat that appears normal under cursory inspection may be revealed to be rough and irregular when seen through a bore scope. Greenleaf's report (Rifle No. 146) details how pressure increased as the number of rounds fired through a test barrel grew larger. This can only be attributable to a deterioration of the throat and leade on that particular barrel. In this instance SAAMI standard barrels were used and showed no irregularities, and it was only when the same ammunition was fired in a 'field' barrel with more generous tolerances and wear in these areas that problems were seen.

Bullet hardness and stiffness: The shape and construction of the specific bullet used can be a major factor in the levels of pressure developed by any given load. Bullets undergo some degree of deformation as they enter the bore, and the force required for them to engrave the rifling and obturate to bore dimensions can vary considerably.

Temperature: We know that pressures tend to increase as the barrel heats up, and a round that produces perfectly normal pressures from a cold barrel might show signs of excess pressure when the barrel is hot.

Work presented here answers questions. Some of the findings support theories offered to explain S.E.E. some don't. We haven't, for example, seen any evidence to indicate that there is ever an explosion, and many authorities doubt that there is. Perhaps what we need is a better name. Taken to its most basic component, what we have is that most fundamental cause of catastrophic failures: a bore obstruction. The difference here is that the offender is the bullet itself effect rather than some external source is both predictable and reproducible in the light of this new evidence, but it is highly dependent upon a combination of factors that produce disastrous results. If one or more is absent, everything will probably turn out fine; but when all come together, pressures rise and, sooner or later, sooner or later, something will fail. While it would appear that slow-burning powders contribute significantly, until now we didn't exactly know what to look for. I think it's at least theoretically possible for a bullet to stop in a barrel if the other conditions are bad enough with propellants other than the slower grades.

Have you ever fired a load that you had used often and suddenly gotten signs of excess pressure such as difficult bolt lift or flattened primers, and then fired another that seemed perfectly normal? I think this happens with some frequency, and our normal recourse is to shrug our shoulders and also be a bright red flag waving in keep on shooting; h6wever, this could front of our nose that is telling us that something is wrong. In the light of these findings, it could be telling us that a bullet did a stutter step before it went on out the barrel. The question then becomes what should we do about it. My first suggestion would be a careful investigation of the condition of the bore, especially the throat or leade to see if there is any erosion or roughness followed by thorough cleaning. A chamber cast might be in order to get precise measurements. If the barrel shows obvious signs of wear or throat erosion, the cure is obviously to replace it or set it back and rechamber. If the barrel appears to be within specifications, however, a change of bullet or propellant may be enough to solve the problem. The importance of this information is that it explains, with laboratory documentation, what can happen when the wheels fall off in the worst way. It seems like such a reasonable answer to many of the mysterious ka-booms that good reloaders have had with good handloads, and it is something we all need to keep in the back of our minds in case we encounter something out of the ordinary. While the data here was generated using the 6.5x55 Swedish cartridge, the observations are not specific to that round. They could occur with almost anything.

[45-70 Chevroner]

I like Jeffrey's load of 3.5 grs bullseye, I like the 110 RN cast boolit, it's a little faster than the 150 gr. and it shoots great out to about 50 yards. It will take a bunny out or a gopher. Ferrol cats just fall over DRT. I don't remember the MV but I think it should be around 700 FPS.

[uscra112]

Bottom line being that you really don't need to worry about S.E.E. in light loads of fast powders using cast boolits. The conditions that create S.E.E. don't exist in that type of load.

You DO need to worry about double charging, so set your loading procedure up to provide robust defenses against letting a double-charged round reach the chamber of your gun. Also "squibs" with no powder or not enough. How many revolvers have been blown up by a squib load followed by a full-charge round?

[squirrelnuttz]

[QUOTE=uscra112;1528129]I can see that the Handloader article on SEE needs to be reposted. Thanks to Larry Gibson for having posted it in the first place...

There's a graphic in the article that did not carry through to this post, so it's probably worth hunting up the original article in the Handloader archives.




[QUOTE/:]


Thank you kindly for posting this article. I had a semi customized military Swedish Mauser explode on me once, got off very luckily.Load was H4350 1gr below min., with 140 gr Barnes X and the second shot of that load in the string,preceded by 3 or 4 120 gr. loads that went off perfectly.The loads in question were carefully weighed by myself with a more experienced reloader literally looking over my shoulder. This on the heels of the bolt sticking shut with moderate loads in the work up stage, thus the reduction.

The explosion, sheared one action screw, shattered the stock,bent the bolt and tokk off the bolt heads, area blew out the top of the receiver, along a line where the receiver had been drilled and tapped for bases.Blew the scope right off in two pieces.The cartridge case was fused to the chamber, I got off with only brass bits in my face and a suspicious stain in my underoos.

This article is enlightening.Thanks again.

[noylj]

thanks for the article.
However, that was NOT a reduced load and does not support a "too light" load of a slow powder making a BANG.
That is a summation of a set of circumstances leading to a factory load going BANG.
Again, the cure, like many factory powder issues, is to go for a faster powder.
There is only so much energy a given amount of powder can release.
The rule still stands: if you are going to light/slower/lower pressure loads, it only makes sense to go to a faster powder.
Also, that filler some recommend could be a bore obstruction by itself.

Note: With some powders, that are right on the edge of burning well at or very near the cartridges max pressure, dropping that pressure will and has left unburnt powder globs in the barrel. This is the danger of even considering lowering the charge weight of H110/296.
I stay away from this particular powder just for that reason. I like 2400, an extremely accurate and well-behaved powder for magnums. Personally, I think the place for H110/296 would be where the starting charge is in the 40-50ksi pressure range--maybe in the newer "super" magnums of some carbine loads.

[Rattlesnake Charlie]

Red Dot.

Bulky, not position sensitive, and clean. I've used it in .30-30 for years. Maybe not as accurate as Unique.

[JeremyV]

I would vote for Trail boss.
I have made reduced loads for my 308 and 338 federal that shoot around 1020fps and as slow as 900 with jacketed bullets. I never have any trouble with them. They seem to group better around 1020 to 1300. my 338 federal shoots about 3/4 inch at 100 with the current load. and the case is full right up to where the bullet seats. (note do not compress trailboss)
Its impossible to double charge one and there is no way the powder can move around in the case.

[Larry Gibson]

Have to disagree. The reported incident, while it occured in a factory, was with a load worked up for production as noted with; "In early 1989 a major manufacturer began development of a load for the 6.5x55mm Swedish that was to be added to their product line. Development was uneventful and all work was done using the copper crusher pressure measuring system, for there were no standards established for piezo-electric pressure measurement in the 6.5x55mm."

The load was initially "worked up" (even factories use the same handloading tools we do in their load development) and tested in a standard SAAMI test barrel for CUP testing. These barrels have much tighter chambers and do not have the freebore that milsurp barrels have or that worn throats have or when shorter bullets are used that create long freebore. It was when the testing of the worked up load not yet in production occured in a M96 Swede rifle with a strain guage (peizo) attached that the SSE symptoms and event occured.

The load used was one with a slow burning IMR powder reduced to meet SAAMI MAPs for the 6.5x55. That and the use in the long freebored milsurp chamber set the stage for the SEE.

Larry Gibson

[hansumtoad]

10 gr of Unique and call it a day. Tangent Zero, Baby.

[felix]

PM from "Rusty W" today...... Pictures included

First shot on the target is the one in the circle, just below the dot center circle. Everything was normal, sounded normal, bolt opened normal, case looked normal. I fire the 2nd shot, it's high & right. Gas blows back in my face along w/other parts of the rifle. Gonna be a while until I get to shoot the Fireball again. The action is bent, bolt is bent, extractor is in the next county. Gonna have to cruise the pawnshops for another donor action looks like. I don't think I double charged. I'm going to pull the remaining loads & see if they check out. I tested a double charge & the powder level is up to the center of the neck. I shook the other loaded rounds and I can hear the powder shake loose inside the case.
Here's some pics...don't laugh tooo hard.

Conditions: 42 degrees, cloudy, close to 60 percent humidity. Ammo and gun close to same temp. 221 fireball stock sizing, 242646, 8 gr BlueDot, Rem std pistol primer, boolit off of the lands, no filler, minimum SAAMI std chamber, level shooting, Savage bolt gun w/Douglas barrel. ... felix

[303Guy]

There is another way a "SEE" can occur, only it's not a SEE, it's a "PEE". That's a Primary Explosion Effect. It too is caused by a bore obstruction from a bullet stopped in the throat. How it happens is a load with missing powder is chambered and fired and the bullet gets lodged in the throat. The shooter just hears a click, pauses, then opens the bolt to discover that he has somehow 'forgotten to chamber a fresh round' and chambers another one, the bullet gets pushed back into the case and since it's a reduced load there is plenty of room for the bullet to go. On firing, a PEE occurs!

How do I know about this? I survived one. It wasn't a reduced load and the bullet had nowhere to go so the bolt wouldn't close. I was lucky.

[uscra112]

A quick analysis in Quickload: A double charge of 16 grains Blue Dot does not fill a .221 Fireball case with no boolit seated. Seat a 45 grain boolit an arbitrary .200 deep in the neck, and you have only 6% compression of the load, easy to overlook when seating the boolit.

Quickload reports this combo at 88,000 psi.

Not at all impossible that this is another case of a heavy overcharge of fast powder being being passed off as S.E.E.

[felix]

Marlin lever guns are proofed at 80,000 psi. ... felix

[Rusty W]

While it isn't totally out of the question that it is possible it was a double charge, I will bet my gently used Mountain Man Sharpening Stone that I didn't double charge. I have been reloading since I was 13 years old, I'm 41 as of last Friday. Countless number of rounds have been shot through shotguns, pistols, & rifles. I've never had a double charge in all those years. Have I made mistakes? You bet. Squibs? Yep. But never a double charge in any cartridge. First time for everything some would say. Not me, not on this. I must admitt, I didn't really think SEE happened because I had loaded for years & never had it happen, till yesterday. I'm now a believer. Under the right conditions, when everything is just right...Boom. And no, I don't believe in BigFoot either...till I SEE one.
Now just for thought. Remember all the scare about cell phones at the gas pump? It's static electricity. When you get out of the car & aren't grounded, grab the pump handle & touch the tube w/the pump, the conditions are just right...boom. Same way with a grain mill. All that dust in the air just looking for the right time & place to go boom. Maybe not a direct correlation w/each other but just showing under the right conditions, strange things happen.

I looked at the Blue Dot cannister and can only find 2 sets of numbers. One is in a white box at the bottom of the bottle. CE 0519, and one is in yellow smudged ink. From what I can make out it reads...08 LOT 258. Not looking to place blame, just showing my findings.
I'm glad/lucky I wasn't hurt. The Savage held together, well kinda. The Douglas barrel is going back to Douglas to be checked out. The action is a gone'er though. At least I can salvage the stock & scope. Now to look for another savage/stevens with a 4.27 action bolt spacing & a .378 bolt head and SEE if I can do it again.
Just joking...

[felix]

Even it was a double charge, so what according to QuickLoad. 88K psi should not have destroyed a modern bolt gun. I bet guns (not unusual for BR guns) that operate at 65K average hit close to 80K on every shot for a microsecond's worth? ... felix

[44man]

Excellent article.
My friend and I both had SEE events in 6.5 Swedes within a month of each other. We both used a near top load of 4831 that we shot for years with great accuracy. Neither gun suffered damage but primers were GONE and a mallet was needed to open the bolts.
Yes, the free bore is a contributing factor. Bullets moved. The rifles were made for very long bullets.
I have switched to Varget and have had no further problems but who knows?
Now you know why I say to keep boolits in the brass in revolvers and do not blow them out with the wrong primer for the case size.
Without the pressure release at the gap, many would be blowing up revolvers. Imagine a LR primer in the .44! Why guys fool with such stuff baffles me.
Failures to fire in the .454 with the SR mag primer that runs out of fire with less then max loads of H110 and 296. Just what would happen if the powder in the barrel behind a stuck bullet DID ignite?
I read what guys do and the hair on the back of my neck stands up but there is always someone coming in that says they do it all the time. Even shooting loads with soft boolits with zero case tension and using a mag primer makes me shudder.
Thank your stars for the gas release at the gap. Wrong components might be the cause of top strap cutting, cone splits and cracked cones. Could it be a stopped boolit and all the gas going out the gap?
Sometimes you need to just sit at your loading bench and think. I am not an engineer or ballistics expert but some things posted are wrong. Stupidity breeds stupidity.
Can a fast powder also cause an SEE event? I suppose it could if the boolit went out and stuck before full ignition. I just do not know enough about it.

[felix]

Most SEE's that happen are not destructive, Jim. Apparently, 8 grains of smokeless is enough to cause havoc. It's a matter of how fast the powder expands (burns) VERSUS how fast the projectile is moving at the time when any remaining granules from an initial burn are instantaneously ignited. ... felix

[uscra112]

What 44man describes in his 6.5x55 is S.E.E. as understood from the data that Larry's source article published.

A large charge of powder is required. A long j-wart, having lots of bearing area for it's cross section helps a lot. That area enhances the static friction of the obstruction, making it much harder to get it to move once it's stopped. And the large charge is required to provide sufficient potential energy to generate the pressure behind that obstruction.

In this Fireball incident, I would ask two questions:

1.) Can the static friction of a single cast boolit ever be enough to sufficiently constrain the chamber volume to get an extreme pressure spike? Default start pressure for lead is 1/3 or less of a j-wart in the Quickload algorithms. (I have to presume that the values used there are supported by evidence.)

2.) Does 8 grains of Blue Dot contain enough potential energy to generate a pressure that would blow that gun up, even if there were a really obstinate obstruction?

I tried to get Quickload to analyze this, but it won't let me use a start pressure more than about 8400 psi. for 8 grains of Blue Dot. This is something like five times the default value for a plain lead boolit, yet the calculated pressure is not quite 21,000 psi.

I tried the same approximation for a full charge of 4831 in the 6.5x55, and it does give scary pressures. Why? Slow powder or no, there's so much more of it that the energy (joules per gram) is over 4 times the available energy in the Fireball load, yet there's only about 2 1/2 times the available case volume. This is only a very rough approximation, but food for thought.

[44man]

Most SEE's that happen are not destructive, Jim. Apparently, 8 grains of smokeless is enough to cause havoc. It's a matter of how fast the powder expands (burns) VERSUS how fast the projectile is moving at the time when any remaining granules from an initial burn are instantaneously ignited. ... felix
That is true, I agree. But why do fellas use loads with wide variations in accuracy? That should be a clue things are not right and a lot of it is caused by case volume changes at ignition.
Now a rifle can shoot great for years but just one bullet that is let go early can ruin a gun. I always worried about the Weatherby magnums with free bore. Free bore reduces pressure but the bullet must be kept moving. I have never heard of a Weatherby with a problem. Was it the shoulder? Or the size of the cases that absorbed primer pressure? I loved mine.
Would using a LP mag primer in the 6.5 eliminate all SEE events?
Food for thought.

[Larry Gibson]

I always worried about the Weatherby magnums with free bore. Free bore reduces pressure but the bullet must be kept moving. I have never heard of a Weatherby with a problem.

Saw a beautiful .257 Weatherby destroyed by SEE many years ago. Light load of old 4831 surplus under a 100 gr j bullet to fire form the cases made from new 300 Win Mag cases. It blew on the 5th shot.

Larry Gibson

[felix]

Light bulbs burn out on transients, like when they are turned on. The same with SEE set-ups. Measurements taken for Quickload are from normal data in normal circumstances. I very highly doubt anyone in their right mind will produce a product for general purpose use using full scale transient response data. Gun sales would approach zero, either by customer response or by governmental restrictions for our "safety". ... felix

[44man]

I always worried about the Weatherby magnums with free bore. Free bore reduces pressure but the bullet must be kept moving. I have never heard of a Weatherby with a problem.

Saw a beautiful .257 Weatherby destroyed by SEE many years ago. Light load of old 4831 surplus under a 100 gr j bullet to fire form the cases made from new 300 Win Mag cases. It blew on the 5th shot.

Larry Gibson
He was doing wrong fire forming that way. I made many Weatherby cases for the .300 out of .300 H&H brass. Always proper loads.

[felix]

We know that now, Jim! ... felix

[mpmarty]

Marlin lever guns are proofed at 80,000 psi. ... felix

Then why in heck do all the manuals restrict loads to 28,000 psi???

[blackthorn]

Quote "He was doing wrong fire forming that way. I made many Weatherby cases for the .300 out of .300 H&H brass. Always proper loads."

That is how I made reloadable .300 Wby brass years ago when I got my .300 Wby mag. All I did was load factory .300 H&H into the Wby and shoot. Worked like a charm and accuracy would have been good enough for deer hunting. The only thing was the fire formed case had a little smaller interior case capacity so I had to be careful working up loads.

[felix]

Proof loads are a one shot deal, hoping to prove the gun will take an average number of industry standard maximum shots at the suggested average pressure per shot for the gun that it is. This pressure is designated by the manufacturer as SAAMI factory loading specs. As far as I know, BR guns are not proofed for pressure by their makers because of the number of them produced kinda' makes them categorized as non-production. ... felix

[Larry Gibson]

He was doing wrong fire forming that way. I made many Weatherby cases for the .300 out of .300 H&H brass. Always proper loads.

Now isn't that the truth:Bright idea:....happened a long time ago before we knew what we know now.........I suggested at the time he use 4895 but he had lots of "cheap" 4831 and, after all, It was the powder for the 257 Weatherby...........:-?

Larry Gibson

[Larry Gibson]

Then why in heck do all the manuals restrict loads to 28,000 psi???

Didn't know Marlins were restricted to that psi????....SAAMI MAP is 42,000 psi for the 30-30.......but then I use Winchester lever guns:p

Larry Gibson

[felix]

I bet Marlin's are also. The big boy Winnies and Marlins are prolly higher and based upon industry standard already for the caliber in question. Don't know, but just guessing. Also, they might be proofed higher too. ... felix

[noylj]

Sorry guys. I still say you're blowing smoke. Handloader did NOT prove S.E.E. happens. Chemical reactions are not voodoo.