swedish mauser incident at the range yesterday

[danyboy]

I went shooting yesterday with my Swedish mauser and got scared ****less when the extractor bent, got a unusual case head separation and got powder in my face coming out of the vent hole.

I had used my usual lucky pet load of 17 gr. SR4759 with a GC cast 150gr boolit. Can't figure out what the heck happened.

[OS OK]

Holly Cow…I'm glad to see you posting this from home, not the hospital. I bet you had to change your drawers!

OS OK

[Dan Cash]

34 grains of SR4759 will do that to you.

[.455 Webley]

Glad your not injured, that could have been much worse. Just out of curiosity how did you manage to open the bolt with the extractor bent like that? What brand of case was that loaded in?

[country gent]

Could be several causes of this here. I would pull down and closely check the remaining rounds as to powder weight, bullet sizes and cases conditions. Head seperation could be over pressure, aged brass or overworked brass. Im not making judgments here but powder bridging on one round and droping with the next thrown charge isnt unussuall. Brass thats been reloaded many times may fail also. old brass may be brittle with age hardening and fail. There are many things here may be one or a combination of several. Im not sure of the top of my head where 17 grn of sr 4759 and 150 puts it pressure wise so not going to comment there. You need to look at the remaining ammo and try to determine whats going on. I would also recomend pouring a little sr4759 in a bottle cap to compare powder from remaining rounds to. Not real scientific but may give an idea.

[danyboy]

NO, I double checked every case before seating bullets to make sure all cases have the same amount of powder and that none of them has a double charge.

[danyboy]

Federal case. The bolt was a pain in the *** to open. Took the stock off, put the action in a vise and in the process, bolt handle broke off. Managed to open the bolt anyway. Had a hard time removing the case. It was exactely like in the picture before attempting to remove it. Cut like a half moon at the head.

[danyboy]

I was shaking all wright. The guy next to me didn't see anything. I wiped my face to check if I was bleeding cause I had felt like powder in my face (thank god I was wearing glasses) but I was allwright.

[danyboy]

I will check all that. Anyhow, It's going to the gunsmith for sure .

[leebuilder]

Could of had a squib prior to your last. Definitely over preasure. Glad you are OK. I had an over pressure once in 6.5 as well. I was pushing the limit with 4895 and j-thingys. My rifle stuck shut and broke the bubba'ed bolt of and blew the casing apart and blew out the primer. Lots of gas in the face.
Be safe

[303Guy]

Looking at that case (a closer zoomed photo would be helpful), I would tend to rule out brittle brass failure. Brittle brass would crack and open up letting out gasses. What you have there is case head expansion with complete failure on one side. Over pressure. The question is, what could have caused that. A double charge or a double bullet would be the first two suspects but you checked the powder levels in the cases before seating so the mystery deepens. Powder bridging is one cause of over charging but then there would have to be an undercharge in there and if it was fired then you would never know for sure, but again, you checked the powder levels so that would seem pretty unlikely. That leaves a mystery!

Is SR4759 a powder that clumps? None of the powder's I use clump. I would imagine SR4759 won't S.E.E. or could it?

[Frank46]

4759 doesn't always measure out through a powder measure as well as we would like. I've been using a lyman electronic scale and a dribbler for years and have loaded a bunch of 7.62x54r with cast bullets and never had a problem. I had some Lapua 6.5x55 match ammunition that was berdan primed. Punched a hole in a primer and got a divot on the firing pin had to replace the firing pin. Rifle is good to go. Frank

[danyboy]

One thing I did that I had never done before with this caliber and petload was using COW filler. Now, would this cause the pressure to go high enough to have something like this happen, could be. I usually do it for pet loads in larger cases and won't ever do it again with the Swedish. Also, perhaps my brass was overused. I will head up to my gunsmith and see what solution he has for me.
Thanks to all for your ideas. Will follow up on this.

[victorfox]

Wow this is ugly... Well I'm on the opposite side of an expert but looks like you have your answer. COW is used to push cases out in fireforming and since there a 6.5mm "obstruction" of steel ahead of the chamber the case went backwards... Thank God you are fine.

[HangFireW8]

One thing I did that I had never done before with this caliber and petload was using COW filler. Now, would this cause the pressure to go high enough to have something like this happen, could be.

Not just "could be." Yes, filling the case with COW is going to greatly increase pressure. The gas has nowhere to expand if the case is full of a solid.

Think of it this way. Your previous pet load had pressure X. X is created by a quantity (defined by your powder charge weight) of hot gas filling a given volume (the empty case minus bullet intrusion). If you had the same mount of powder in a huge case, say 416 Rigby, your pressures would be lower, right? Now let's go in the opposite direction.

Halve the available case volume by replacing air with a solid, and you (roughly) double the pressure. Halve it again and you double pressure again. Keep going until you have no air space for the hot gas to expand into. Your pressure is now off the charts.

You can get away with topping off large loads of medium-slow powder with COW, because you aren't taking away much, and debulleting occurs sooner. Take away all the case volume from a near full pressure load of fast-burning powder, that's another matter entirely.

[DougGuy]

^^ I'm going with this one. Not counting the primer, there are basically only three ways to increase pressure and that is add more powder, add more boolit weight, or reduce the volume where the powder burns. In the scheme of things I think this is a plausible explanation of what happened, because cow is a solid so it is the same as reducing volume even if it is dispersed in the case because it displaces air and doesn't compress like air does.

Since air compresses as pressure rises, I will differentiate between the words static and dynamic. Static volume being the absolute case volume minus the stem of the boolit. Dynamic volume being the amount of volume that is compressible by combustion.

Adding cow does nothing to change the static volume, but has a drastic effect on pressure because it greatly lowers the dynamic volume.

Editing, let's say the case has an absolute volume of 3.6cc's and a factory load is duplicated with 17.0gr of SR4759. The powder takes up 2.7cc's of volume, leaving 0.9cc's of empty space. You add 0.9cc's of cow to keep the powder positioned in the case as it was loaded and assemble the round with the boolit.

So in this scenario the dynamic volume of the case was reduced by 25%. Now, go find a cartridge that has basically 75% of the static volume as the Swedish Mauser load, and extrapolate the same boolit weight and the same 17.0gr of SR4795. Is this way off the end of the max recommended charge weight for the smaller cartridge? Now we have the scenario that set up this KB.

By the same token, if you compute the volume of the cow you intend to add, and you then go find a cartridge where the case volume equals your remaining volume after subtracting the volume of the cow, then run your intended load data into the equation and see if it is within suggested min. and max. of the smaller cartridge. If it is, then it is likely safe enough to shoot. If it is not, it is likely to enable another over pressure event.

[wddodge]

Ok, I have to ask... What is COW?? I've used bits of dacron as a filler but have no idea what this is.

Denny

[HangFireW8]

Cream of Wheat.

Really.

I've used it to fireform .257 Roberts into .257 RAI with light powder charges. It was such a hassle I switched to using full-up loads of 4895. The hassle part was a little COW would stay in the shoulder of even the most well-formed cartridge, and on extraction litter the chamber and magazine.

[William Yanda]

14 posts later we find out the change included COW. And they say insanity is doing the same thing over and over, expecting different results.
Glad you weren't hurt. Guess I won't be using COW like that.
Bill

[Hamish]

One thing I did that I had never done before with this caliber and petload was using COW filler. Now, would this cause the pressure to go high enough to have something like this happen, could be. I usually do it for pet loads in larger cases and won't ever do it again with the Swedish. Also, perhaps my brass was overused. I will head up to my gunsmith and see what solution he has for me.
Thanks to all for your ideas. Will follow up on this.

What was Frank Barones saying on "Everybody Loves Raymond"??????

or

Dude, you missed out on your Darwin Award by *that* much,,,,,,,,,,,

[curator]

Cream of Wheat cereal will compress into a near-solid mass under pressure. The 6.5X55 Swede is a very bottle-necked case where the COW may not "flow" through the shoulder area and can compress into a solid plug. Pressures can go through the roof causing what you have experienced. COW is GREAT in straight wall or tapered cases, but can and will give problems in bottle necked cases. If you need a filler to keep the SR4759 at the rear of the case, use dacron fluff or Spherical plastic shot buffer. Both of these work without raising chamber pressures on the Swede except a little bit as they flow easily into the bore. I have had similar extreme high pressures using "Puff-lon" filler in the swede and not use powders like Alliant 2400 or IMR 4198/3031 or 4895 instead of relying on fillers to get a clean burn,

[JeffinNZ]

Please, please, please DO NOT do this sort of thing again. You are lucky to be alive and thank goodness for strong bolt actions.

[Silverboolit]

I don't think that I have ever seen factory ammo with breakfast food listed as a component.

[victorfox]

Well as no one told you yet pull all the remaining loads and burn the tainted powder in the garden and use the rest of the COW to make your "mingau"....

[danyboy]

Hangfirew8,
Makes a lot of sense. I must have bumped up the pressure way too high by filling with the COW.

[danyboy]

I don't think that I have ever seen factory ammo with breakfast food listed as a component.
You will never find factory ammo with cast boolit and reduced powder charge either.

[danyboy]

No worries, never again.

[danyboy]

curator,
You're wright. I have used fillers with 11.15 x 60R cases which are almost similar to 45-70 cases without a problem. This was the first time with a bottle neck case, and the last one.

[dverna]

There was an interesting study done a few years ago by a SASS shooter using COW in a 45LC. Over a period of months he began to see signs of higher pressures. It seemed the stuff "caked up". I will never use something like that as a filler

Use Dacron or a powder that does not need a filler for reduced loads.

[country gent]

Adding a filler to an existing load with out starting low and working back up again is very dangerous. The filler changes cases load density by filling airspace. In some instances it even creates a compressed loading. In reality it also increases the projectile wieght by what its adding to the mix. IE a 150 grn bullet with 20 grns of filler is for practical purposes a 170 grn projectile now. A border max load with filler added can become over max easily. Another is some powders react diffrently with little to no airspace or compressed. Cream of wheat, grex, and others have been used for a long time with good results when the load is worked up with them from the start. Also Kapoc, dacron, toilet tissue and other fibers are used but from the start of load work up. Older tired cases, a filler added to the load, may be the combination here.

[hardy]

Hey DougGuy ,I,ve read your post a few times and am confused.17 grains of 4759 is 1.6 cc.s or thereabouts so 1,9 cc,s of COW is being used to fill the case,and that ratio is trouble looking for an outlet!Apologies if I missed your point but those(my) figures are way out of line.I personally use grits in nothing smaller than 7mm and then only after care working up my loads with slower powders and hence less volume of filler. Be safe,Cheers,Mike

[ELFEGO BACA]

Years ago a friend was shooting my cast bullet handloads in my swede.
He had one shot with a sharp recoil.
I attributed it to a double charge of SR4759.
I now weigh each cartridge after manufacture.
This should reduce the potential of a double charge.
I have also found a doubled bulletted 30/06 handload using this weighing process.
Be careful!

[303Guy]

Years ago a friend was shooting my cast bullet handloads in my swede.
He had one shot with a sharp recoil.
I attributed it to a double charge of SR4759.
I now weigh each cartridge after manufacture.
This should reduce the potential of a double charge.
I have also found a doubled bulletted 30/06 handload using this weighing process.
Be careful!
Any idea how that might have happened?

[ukrifleman]

I will check all that. Anyhow, It's going to the gunsmith for sure .

Apart from anything else and for piece of mind, make sure that the headspace is checked and get the locking lugs on the bolt crack tested.

ukrifleman

[John Boy]

Swedish Mauser = bottle neck case
Believe your 4759 powder charge with COW in that bottle neck case created an abnormal position sensitive with high pressure condition that ruptured the web of the case on ignition

[gwpercle]

One thing I did that I had never done before with this caliber and petload was using COW filler. Now, would this cause the pressure to go high enough to have something like this happen, could be. I usually do it for pet loads in larger cases and won't ever do it again with the Swedish. Also, perhaps my brass was overused. I will head up to my gunsmith and see what solution he has for me.
Thanks to all for your ideas. Will follow up on this.

Heck Yes....I don't care what "others" say, stay away from cream of wheat , and cornmeal fillers and small bores. It can be a problem. Tufts of Dacronor kapok fiber might be safer....I prefer to use no fillers whatsoever .
Gary

[Wayne Smith]

What Curator said. By using COW you created a smaller airspace and essentially created a bore obstruction as well as that cartridge sized mass of COW tried to get out the neck of the case.

[PS Paul]

So are you fellas tryin' to say that one should not use cream of wheat as a filler in 6.5x55?

[John Boy]

I reload under this adage: Never use fillers in any bottle neck cases ... using position sensitive or not powder

[Scharfschuetze]

Fillers designed as such can improve your ballistics and accuracy in some cases. Their use can be time consuming, but the results can be worth the effort if you are nailing down that last smidgen of accuracy. Puff-Lon is what I use from time to time in rifles that will recognize the improved ballistic uniformity. Grex shot load buffer is also useful.

The use of these materials can reduce the extreme spread in velocities by half and the Sd by a third. Accuracy is often improved by over a hundred percent.

Mentioned in posts above is the use of Dacron (pillow filler). It has also proven to impact accuracy and uniformity positively if used correctly. A large bag of the stuff is pretty cheap and can be bought at any sewing store. Larry Gibson at one time had a very informative sticky on its use.

Examples:

10 shot groups: With the issue sights fired off a bench rest with the same load on the same day without and with a filler in the 7.65mm Mauser at 50 yards. The accuracy holds well at extended ranges and I often out shoot scope sighted modern rifles at 200 yards from both the bench and off hand with my best loads using the filler.

[DougGuy]

Hey DougGuy ,I,ve read your post a few times and am confused.17 grains of 4759 is 1.6 cc.s or thereabouts so 1,9 cc,s of COW is being used to fill the case,and that ratio is trouble looking for an outlet!Apologies if I missed your point but those(my) figures are way out of line.I personally use grits in nothing smaller than 7mm and then only after care working up my loads with slower powders and hence less volume of filler. Be safe,Cheers,Mike

Actually I should have clarified that I was just using the volumetric figure I used as an example, and it should have been noted that the figure used does not accurately reflect actual volume of powder, I was just using those figures to show an example of how the reduction of the dynamic volume could be figured out before the load is assembled.

Grits, COW, any solid used as a filler will reduce case volume, so yes you approached it in the correct manner afaict.

[hardy]

DougGuy,Gotcha loud and clear.Cheers,Mike

[Don Fischer]

I have never understood the using of COW as a filler. I do use 1/4 sheet of TP in my 30-06 when using Red Dot. All it's for is to keep the powder at the flash hole. If I was blowing out case's, I just load a mild enough load to get the job done.

[leadman]

I use alot of 4759 and and have found no need for a filler with it. I do use COW in fireforming cases with no projectile in bottlenecked cases. I use polyfil in some cases as a filler but one has to back the powder charge down and work back up when adding a filler to an existing load.
I also weigh each powder charge, especially when using 4759 as it will bridge in the powder measure.
Glad you were not hurt.

[gnoahhh]

I have never understood the using of COW as a filler. I do use 1/4 sheet of TP in my 30-06 when using Red Dot. All it's for is to keep the powder at the flash hole. If I was blowing out case's, I just load a mild enough load to get the job done.


Have you ringed any chambers yet with that approach? 1/4 sheet of tp tamped in tight enough to secure the powder at the base of the case is in effect a secondary projectile inside the case, and when it contacts the base of the bullet it stops for "a second" with pressure building up behind it. Result, sooner or later: an unsightly ring in the chamber. Don't believe me? Research the phenomenon. A filler needs to be light and fluffy and take up all the air space, not leave air space exposed between it and the bullet. That's why pillow stuffing and the old standby kapok excels at the task.

While I concede the efficacy of filler use, in some circumstances, I shy away from their use.

[danyboy]

Please, please, please DO NOT do this sort of thing again. You are lucky to be alive and thank goodness for strong bolt actions.
For sure, I will not do it again in bottleneck cases. I since used tiny bit of cotton puff against the powder for my Mauser 43 pet loads as I have been for decades without any issue but the COW in the Swedish mauser was the first and last time. COW is convenient and safe for fireforming without a bullet .

[robg]

I don't use fillers in any loads ,if your worried about powder position tip the barrel up between shots.I use shooting glasses too ,they did their job OK.

[Char-Gar]

Cream of Wheat cereal will compress into a near-solid mass under pressure. The 6.5X55 Swede is a very bottle-necked case where the COW may not "flow" through the shoulder area and can compress into a solid plug. Pressures can go through the roof causing what you have experienced. COW is GREAT in straight wall or tapered cases, but can and will give problems in bottle necked cases. If you need a filler to keep the SR4759 at the rear of the case, use dacron fluff or Spherical plastic shot buffer. Both of these work without raising chamber pressures on the Swede except a little bit as they flow easily into the bore. I have had similar extreme high pressures using "Puff-lon" filler in the swede and not use powders like Alliant 2400 or IMR 4198/3031 or 4895 instead of relying on fillers to get a clean burn,

Bingo...we have A winner!

[HangFireW8]

Bingo...we have A winner!

Not really. CoW can ring chambers in straight walled cases, and has, which is not what I would call "great". The rest of the post is good.

[gwpercle]

One thing I did that I had never done before with this caliber and petload was using COW filler. Now, would this cause the pressure to go high enough to have something like this happen, could be. I usually do it for pet loads in larger cases and won't ever do it again with the Swedish. Also, perhaps my brass was overused. I will head up to my gunsmith and see what solution he has for me.
Thanks to all for your ideas. Will follow up on this.

Unfortunately ...yes. Fillers in bottle neck cartridges , in my opinion, are to be avoided. And what has happened in your case tends to reinforce that thought. Lots of fellows will say they have done it for 40 years with nary a problem....then this happens. Proven load, except for COW filler, and oops .

Sorry about your rifle but thank the Lord you are not hurt. You can can get another rifle , hard to get another you or new body parts.
Gary

[GONRA]

GONRA sez read Char-Gar for a great exlaination of wots going on.
BUT - any fluffy filler can do this. Dacron etc, too - NOT just COW.
(Personal 7.62x54R Russian experience decades ago...)
Jurt have to use too much. (Whatever THAT is.)

[Buckshot]

http://www.fototime.com/88A840C9F95788A/standard.jpg

Double charge of 4227 under a Lyman 311284 in a low number 1903 NRA sporter.

http://www.fototime.com/2FC3C32627AA38A/standard.jpg
Boltface. You can see the metal that was blown or broken off by the high pressure gas.

http://www.fototime.com/940A4AEA7C819EE/standard.jpg

Bottom of the receiver and lug recess. Pictures I took, but which didn't come out were of the lug setback on the receiver, and where the 3rd "safety" lug setback into the rear bridge.

In case anyone is interested the slug tripped the PACT chronograph at 3018 fps.

................Buckshot

[swheeler]

In case anyone is interested the slug tripped the PACT chronograph at 3018 fps.

................Buckshot

Geeeesus, if you wanted a 300 Ultra Mag you should've bought one!:kidding:

[Dutchman]

Scrap the receiver.


Dutch

[izzyjoe]

I agree with Dutchman, hang on the wall in the back of the shop, and from time to time look at it and be thankful that you were not injured!

[Tar Heel]

Assuming your reloading practices are sound and you did not have Bullseye powder on the bench.....

You experienced either:
1. Firing another round into a bore obstruction after a squib round fired.
2. You double charged the case which is very common in very light loads.
3. You experienced a "pressure excursion" using minimal powder charges in bottle-necked cases. This is called "detonation" by the ballistic experts and while a rare event, does occur.

Glad you are OK.

[Hamish]

I seem to remember Buckshot posting that long ago, IIRC, I don't believe it was his rifle,,,,,,

[swheeler]

You are correct that he posted it long ago, I think on the site before this one. IIRC it was his rifle and was loading 4227 powder, figured he got a double charge.

[Char-Gar]

We have fought the "filler wars" on this board and it's predecessors for many years and I had thought they were about over. I don't think there will be any agreement this time around either.

There are some folks who believe that a Dacron fillers is a good thing. There are others who trace ringed chambers to it.

There are others who feel that organic fillers like Cream of Wheat, Oatmeal, Coffee and the like are great things. However as illustrated in this post, when used in bottle neck cases, they can form a hard plug and push pressures through the roof. They tend to absorb moisture and form a very hard plug.

There there are the folks who use non-organic fillers such as Grex like materials. Precision Shotshell Buffer is a common choice. Unlike organic materials there won't hardened and form a plug, just blow out the muzzle. There is a small white cloud at the muzzle that smells like hot plastic.

I hold the opinion that fillers have limited use. I only use PSB when using very slow machine gun ball powder (WC872) to fill the case to form a compressed charge, which greatly assist in a clean burn. Even then, I only use 1 to 1.5 ccs of PSB. I have found 50/WC872 to be a great powder charge for the 30-06, .308 Win and 30-40 Krag. Only the larger 30-06 requires any PBS to form a lightly compressed load. This will push 165 to 200 grain cast gas check bullets 1.8K to 1.9K fps depending on all the various factors involved.

There are so many powders that require no fillers for good cast bullet performance and it seem hardly worth the effort and risk to play with them.

[Char-Gar]

You are correct that he posted it long ago, I think on the site before this one. IIRC it was his rifle and was loading 4227 powder, figured he got a double charge.

That is my memory as well. I lifted the pics at that time and still have them on my hard drive. They illustrate quite well what happens when a low numbered 03 lets go. They turn into fragments whereas the high number 03s. swell up and lock up when they let go.

The low number 03 don't fail at any higher rate or pressure than the higher number versions. The difference is what happen when they do let go.

The Krags had the same imperfect heat treatment as the low 03s, but the design doesn't trap the gas like the 03 design does.

[Sur-shot]

By the way, the test pressure for every 6.5x55 Swedish Mauser gun is 65,992 psi, with no adverse effect. Every gun must stand up to one round of that blue pill, pressure test. So you were way above the standard pressure of a 30-06.
Ed

[Buckshot]

..............Yup, it'd been posted several times over the years. A very valuable lesson, especially for one who thought his reloading habits were top notch. Not so much as the results show :-) No injuries. The action was shattered (and that's the correct word) because the casehead let go. This old NRA sporter had belonged to my great grandfather. My grandfather gave it to me along with quite a collection of factory/military 30-06 ammo. I happily and gleefully shot it all up over the years. Amazing to me is that the bore wasn't trashed due to corrosive priming, as I KNOW a lot of it was old military stuff. All I ever used was Hoppe's #9, because that's what g'pa had :-) I had it all shot up before I could drive, and only shot it on the occasional visit.

After I got out of the Navy in '73 is when my real shooting/reloading started and that old "Sprangf'ld launched many a factory round and reload (cast AND jacketed) downrange. What I learned is that simply peering down though a case's mouth (especially one as long as the '06) is no bueno por ca-ca, as per the example of the result in the photo's. Ever since, I use a 1/4" x 3" wooden dowel as a positive check on partial/light loads.

I also got to see the aftermath of a guy shooting one of his buddies reloads at the range one time. I dis-remember the cartridge but the rifle was a stainless Savage bolt action, which managed to blow the barrel out of the action into the dirt about 10' in front of the bench. His scope's objective was bent straight up, and other then the missing barrel nothing else seemed amiss :-)

..............Buckshot

[Kestrel4k]

By the way, the test pressure for every 6.5x55 Swedish Mauser gun is 65,992 psi, with no adverse effect. Every gun must stand up to one round of that blue pill, pressure test. So you were way above the standard pressure of a 30-06.

I was curious to model the OP's two loading configurations with Quickload:

From my understanding of the OP's postings (please correct if wrong), the standard load was 17gr of SR4759 w/ a 150gr cast bullet; then the excess case capacity was eliminated via Cream of Wheat to result in the outcome posted in this thread.

Although QL doesn't have a powder file for SR4759, I substituted 2400 for a comparable burning rate.
Big assumption I know, but it could still give us a ballpark figure.

The initial (& functional) 150gr cast load could have had a peak chamber pressure of ~21,000 psi - sounds reasonable so far.

Eliminating the unfilled case capacity with an uncompressible solid (COW in this case) could yield a new peak chamber pressure of something on the order of ~115,000 psi.

This assumes the COW was able to flow through the bottleneck and didn't compress into a unit, further increasing pressures beyond this figure.

Again, some pretty big assumptions for modeling, but it at least provides something to work with. Idle curiosity on my part is all.
Best regards,

[EDG]

use 4227 as a substitute for SR4759


I was curious to model the OP's two loading configurations with Quickload:

From my understanding of the OP's postings (please correct if wrong), the standard load was 17gr of SR4759 w/ a 150gr cast bullet; then the excess case capacity was eliminated via Cream of Wheat to result in the outcome posted in this thread.

Although QL doesn't have a powder file for SR4759, I substituted 2400 for a comparable burning rate.
Big assumption I know, but it could still give us a ballpark figure.

The initial (& functional) 150gr cast load could have had a peak chamber pressure of ~21,000 psi - sounds reasonable so far.

Eliminating the unfilled case capacity with an uncompressible solid (COW in this case) could yield a new peak chamber pressure of something on the order of ~115,000 psi.

This assumes the COW was able to flow through the bottleneck and didn't compress into a unit, further increasing pressures beyond this figure.

Again, some pretty big assumptions for modeling, but it at least provides something to work with. Idle curiosity on my part is all.
Best regards,

[Shiloh]

I went shooting yesterday with my Swedish mauser and got scared ****less when the extractor bent, got a unusual case head separation and got powder in my face coming out of the vent hole.

I had used my usual lucky pet load of 17 gr. SR4759 with a GC cast 150gr boolit. Can't figure out what the heck happened.

DO you trickle powder?? I loaded that powder in a Springfield. I used a designated caseful of powder for trickling. Somehow it got mixed in.
I was about four gr. over maximum load for a cast boolit. I was able to open the action and straighten out the extractor. Been shooting it for years since with no issues. Thank goodness it was an '03 rather than a Krag. I now double check, no longer trickle charges, and weigh the finished rounds.

I learned my lesson.

Shiloh

[guicksylver]

:drinks:..ata boy...so now we know why COW MAY at times be appropriate for STRAIGHT walled cases like the 45-70 , 38-55, 32-40..BUT NEVER in a bottle neck case...

Also ..ALL powders will bridge given the right conditions..throw away the loading blocks when using fast powders in rifle cartridges... weight each charge AND load them ONE AT A TIME...too slow..you say ..I've had no problems you say..well NOT YET..you haven't..but now you know what you've got to look forward too..

As for the other Dacron type fillers ..perhaps they work..they don't for me ..but if you're not experienced enough and know exactly what you're doing they can blow groups and ring a barrel..I know guys are going to chime in here who have used them successfully...but not everyone follows the best practices for doing so and have ended up either ruining groups or barrels..

Really glad you got through this unharmed..sorry for the loss of your gun...eat the rest of your COW, get a new gun, forget the fillers and load one at a time..SLOW DOWN..

[jsn]

IIRC the concept is that anything that is a de facto wad in a bottle neck case could lead to ringing the chamber or worse.

COW, an actual wad, filler compressed that acts like a wad, etc.

I have been hand weighing all of my rifle charges and any magnum pistol for some time. There's too much at stake.

[Larry Gibson]

The key to using a Dacron filler is to use it correctly. Just like most everything we do in reloading there are correct ways to use/do things. There are also incorrect ways. Do them the incorrect way is what gets you into trouble.

I do not recommend a COW filler, even in straight walled cases.

I never recommend a wad which leaves a space between the wad and the base of the bullet.

There is a distinct difference between a wad and a filler for the use discussed here.

The OP stated this;

"One thing I did that I had never done before with this caliber and petload was using COW filler. Now, would this cause the pressure to go high enough to have something like this happen, could be."

The obvious answer to his question is; YES.

Classic case of using the wrong type of filler and not understanding the correct use of a filler thus using it incorrectly. Both serious errors, fortunately the OP was not injured.

[yeahbub]

Wow, what a wake-up call! That case condition tells what happened, though not what led to it. Not only massive extrusion, but major separation as well. From experience, I attribute this to three things: the decrease in expansion space occupied by the cream of wheat, the added mass, and the plug it formed when slammed forward blocking the exit. The interlocking nature of the granules under such pressure likely compressed it into a near-solid mass which had to be made to flow through a 6.5mm hole to escape. Very fortunately, it did. Unfortunately, not before some damage was done, but you were uninjured! What a generous blessing!

The M93 Mauser action is stronger than commonly given credit for. Some years ago, H. P. White Labs was tasked with testing two Swedes to destruction when they began to be imported and people were concerned about their safety. IIRC, one blew at 98,000 psi and the other at 106,000 psi. The report is published, for those who are interested, but I no longer have the link for it.

[prsman23]

Glad you are ok!


Sent from my iPhone using Tapatalk

[Larry Gibson]

but yet I still can find 8 year old posts through google searches using Cream of wheat as a filler

You can find a lot of things via a google search that are unsafe. Just because it is on the internet does not mean it is true, factual or safe.

I have measured the pressures of enough loads in a "straight walled" 45-70 case using different powders with a COW filler to know how quickly and sometimes dangerously if raises the psi. It was so indicative of excessive psi in the 45-70 there is no way I would even test it in a bottle necked cartridge.

[rintinglen]

Over forty years ago, The American Rifleman ran a public safety article disavowing the previously recommended practice of using Cream of Wheat Fillers. There had been numerous reports of ringed chambers and damaged rifles, to the point that they finally declared that practice to be unsafe. The use of dacron and kapok fillers was also thrown into the discard at that time.

I do not use fillers anymore. I can't easily replace my firearms anymore, and the cost of repairs has grown exponentially over the years.

[richhodg66]

The key to using a Dacron filler is to use it correctly. Just like most everything we do in reloading there are correct ways to use/do things. There are also incorrect ways. Do them the incorrect way is what gets you into trouble.

I do not recommend a COW filler, even in straight walled cases.

I never recommend a wad which leaves a space between the wad and the base of the bullet.

There is a distinct difference between a wad and a filler for the use discussed here.

The OP stated this;

"One thing I did that I had never done before with this caliber and petload was using COW filler. Now, would this cause the pressure to go high enough to have something like this happen, could be."

The obvious answer to his question is; YES.

Classic case of using the wrong type of filler and not understanding the correct use of a filler thus using it incorrectly. Both serious errors, fortunately the OP was not injured.

There's a sticky about fillers in which, Larry gave an excellent write up on when it's appropriate and how to do it correctly. I've followed this advice and it has helped a good bit in some instances and I never had a problem. I always scratched my head about using cream of wheat, just never seemed like a good idea so I never did it. The Dacron works in some applications.

Sticky here;

http://castboolits.gunloads.com/showthread.php?109280-The-proper-use-of-fillers