Channeling P. O., Mauser blow up project

[copperlake]

You might slowly work up with a predictable powder like 4198 to find the point where the primer pockets fail and see how that corresponds to the Quickload calculated pressures. Once you start exceeding the strength of the primer pockets it may not take much more to totally destroy a case head and the receiver.

I've been mulling over two powders: 4227 and 4198. I know nothing about them other than 4227 is faster burning than the latter. I'm working at getting some 200 gr bullets used with a 3031 50.6 gr load. According to DCM's software, it will theoretically produce around 66,000 psi. That of course, is seriously above what would be considered a safe load for a '93-'96 action. Let's call it a good proof load. I'll shoot X loads, unscrew barrels and check for set back. That is, if they still are together! Then will proceed with some hotter loads to the end-o. As a matter of fact, according to DMC, the loads I've already tried (showing no signs of over pressure) are 'unsafe'.

The system works really well and the only thing wrong is just an annoyance; when firing, the bang makes a crazy penetrating sympathetic resonance in the various oxygen and argon tanks that shoots right through ear protection. Interesting.

Thanks for the input.

[paul h]

The thing to remember is you have two possible failure modes. One is a massive overload that will cause the steel to yield, the other is repeated overloads that cause fatique failure.

With a case hardened mild steel reciever I would expect a single massive overload to cause the action to yield somewhat like a baloon, i.e. just swelling up. With a fatigue failure or modern harder steels I'd expect more of a fragmentation type failure.

[Chicken Thief]

The system works really well and the only thing wrong is just an annoyance; when firing, the bang makes a crazy penetrating sympathetic resonance in the various oxygen and argon tanks that shoots right through ear protection. Interesting.

The old miners would open their mouths when blasting so the shockwave would hit both sides of the eardrum at the same time. No split eardrums.
Next time firing try holding your nose with one hand and have your mouth closed. The sound just might get in there the "back" way?

[copperlake]

Bummer. Well, I can't find a grain of 4227 or 4198 powder in driving distance. I haven't called anywhere in Anchorage but I'm not going to drive 225 mi. just for kicks. I can't even find 8mm 200 gr. bullets, so I'll get some off GunBroker to continue with the 3031 experiment. I've heard that ammo is tight these days but I had no idea.....Everyone I talked to in Kenai/Soldotna just laughed when I asked when they might be re-supplied!

[izzyjoe]

[QUOTE=copperlake; I've heard that ammo is tight these days but I had no idea.....Everyone I talked to in Kenai/Soldotna just laughed when I asked when they might be re-supplied![/QUOTE]

i know what you mean!

[EDG]

If you have any pistol powder and you cannot proceed otherwise you can duplex your load by adding one grain of pistol powder and subtracting one grain of 3031. Just put the pistol powder next to the primer and top off to a compressed load of 3031.

Bummer. Well, I can't find a grain of 4227 or 4189 powder in driving distance. I haven't called anywhere in Anchorage but I'm not going to drive 225 mi. just for kicks. I can't even find 8mm 200 gr. bullets, so I'll get some off GunBroker to continue with the 3031 experiment. I've heard that ammo is tight these days but I had no idea.....Everyone I talked to in Kenai/Soldotna just laughed when I asked when they might be re-supplied!

[copperlake]

If you have any pistol powder and you cannot proceed otherwise you can duplex your load by adding one grain of pistol powder and subtracting one grain of 3031. Just put the pistol powder next to the primer and top off to a compressed load of 3031.

ED, Ackley used duplex loads (see Ackley, Vol II Handbook for Shooters & Reloaders, pges 3-9) to great effect. As a matter of fact, I think he may have done so in order to wreck Jap actions! However, my sincere hope is to get as much data as we can from what we have. Alas I don't think there is a way to even hypothetically predict what pressures are produced from duplex loads. As has been stated by others here, I's not possible to have it all - a nice, work up to it, failure - but, I'd like to do the best we can to get the most bang for the buck. I do so much appreciate ll the input. This alone has made it worthwhile. Cast Boolits is an outstanding community.

It looks like I may be able to get some 220 gr. bullets from Anchorage. I haven't communicated with DCM yet on what we can cook up with 3130.

[copperlake]

The old miners would open their mouths when blasting so the shockwave would hit both sides of the eardrum at the same time. No split eardrums.
Next time firing try holding your nose with one hand and have your mouth closed. The sound just might get in there the "back" way?

I am going to try that! Thanks for the tip, it makes sense.

[EDG]

Glad to see you want to get the data. I don't think it is possible to ship haz mat but it is possible to ship loaded ammo. I wish I had a few 50 BMG cases. I could load them with the powder you need and a cast 50-70 bullet.....

[DCM]

Update on shipping ammo.
Fed-Ex won't do it anymore, USPS never has.
I spent a ton of time sifting through the UPS website and ended up calling them.
UPS will BUT it Must be Ground only, they will not let you do it between Alaska and the lower 48 as it can't go through Canada and can only be shipped ground.
The package can have a maximum weight of 66 Lbs., Ammo must be 50cal. or smaller, Must be tightly packed in an inner package(double boxed, not loosely packed) and it must be labeled cartridges small arms Orm-D (approximately 3"X5" label) on front.

Terrorists and obamites make things complicated!

[copperlake]

DCM, you've gone way beyond the call! Today I got some 220gr. Sierra Game King SBT bullets from Sportsman's Warehouse. I was able to cram, and I mean cram, 51.5 grs. of 3031 into a case. I'll PM you the COL and bullet particulars tonight.

[Multigunner]

The system works really well and the only thing wrong is just an annoyance; when firing, the bang makes a crazy penetrating sympathetic resonance in the various oxygen and argon tanks that shoots right through ear protection. Interesting.

I noticed the same effect when firing a silenced .22 pistol not far from a half full heating oil tank, pointed away from the tank of course.
There was no decernable report from the pistol but a sound came from the tank as if it had been struck by a iron rod.
Near as I could figure whatever sound did escape the silencer was in a frequency above or below human hearing, but the echo was stepped up or down the frequency scale by reflecting from the tank.
I never noticed that sort of effect with an empty or full steel tank of any kind, only the large half full oil tank.

[waksupi]

I experienced something like this some years ago, hunting antelope over on the east side. I was in a large bowl valley, with a huge corrugated metal barn in the bottom. I shot across the bowl at an antelope, and you would have though that whole barn had fallen down. Kind of scared me, as I had never experienced anything like that before, or since.

[copperlake]

waksupi and Multigunner, thanks for those comebacks, very much similar to what I experienced. It's all out of proportion to what one would expect and thus shocking. When this happens with what I'm doing it is most unpleasant; it almost has a neurological component.

On the blow-up front, DCM reported that said load would produce 101 KPSI, a little more than I want and could easily (?) total the actions so asked if he could come up with something shy of 85 KPSI, which is where brass begins to flow. Soon, somethin' be happenin'!

[EDG]

>>>On the blow-up front, DCM reported that said load would produce 101 KPSI, a little more than I want and could easily (?) total the actions so asked if he could come up with something shy of 85 KPSI, which is where brass begins to flow. Soon, somethin' be happenin'! <<<<

sounds like an opportunity to "work up" a load lol

Regardless of what the software says, the brass will only take XX 1000 psi before it leaks. Anything above that may blow the case head and destroy your action.
The software has no idea what the limit on your brass is but you can find it by working up to it. If you start too high you will only get a one shot test.

[Multigunner]

Some cartridge brass is a bit tougher than others. The 65K CUP-85K PSI figure is for common commercial cartridge brass, and may not apply equally to every type of cartride case according to casehead design.
I think it was in reference to Mauser/DWM design type case heads, which includes many rimmless full power cartridges such as the .30-06.
I'm fairly sure that DWM did not invent the rimmless casehead, but they did develop it to a high degree.

Proof test cartridge cases used by governments are often of a more durable brass, but some privately owned testing facilities use standard commercial Winchester/Olin cases for most testing. At least some reproductions of records from HP White seemed to indicate this.
Most proof test cartridges are in the 75,000 PSI or less category. The U S Army HTP cartridge for the 7.62 NATO generates aprox 64,000 CUP.

In attempts to break a Garand receiver the Army used special heavy duty cases and loads of 125,000 CUP.

Some long range target shooters have tried two piece cases with a brass case body threaded into a steel case head.

[copperlake]

Huston, we have ignition.

DCM got back to me and I went out and set a few off. Here are the results:

FIREARM:1896 Swedish action 1919, 8mmTurk barrel
BULLET: 8mm Sierra 220 gr. Game King spitzer boat tail at 3.075" COL
CARTRIDGE: Remington
PRIMER: Remington
Stock cartridge head diameter - .468

LOAD DATA by DCM:

52g 3031 will be ~104,716 PSI
51.5 - 101,179
50.5 - 94,484
49.0 - 85,305 ALL COMPRESSED LOADS
47.1 - 74,983
46.0 - 69,592

ROUND

1) 48 grs. 3031 No sign of excessive pressure, easy extracion
head dia. .468

2) 49 grs. 3031 No sign of excessive pressure, easy extracion
slight polishing on cartridge head face from bolt. Head dia. .467

3) 50 grs. 3031 Flatened primer, slight bolt stiffness, slightly harder
extration. More pronounced polishing. Head dia. .470-.474, shaping
itself to bolt head.

4) 51.5 grs. 3031 Primer blown away, not a trace of it found, more
polishing. Head dia. .481, Primer pocket .224 (.205 normal).

Here is a pic of the cases:


Extraction was very easy until last round. A 1/4" wood dowel just pushed by hand for the first three, then a tap with a hammer on the third, then a metal rod and hammer tap on the last. Seeing as I was behind a wall, I did not see anything or hear any shrapnel from the disappearing primer. On the last two rounds there was a very strong odor of ammonia after ignition, something I've never experienced before. These hot loads did not produce the strange resonance from the first try. For all the world the first three rounds behaved as one would expect, absolutely nothing untoward. One would think that this gun was absolutely designed for the 8mm Mauser.Of course, my kisser wasn't in proximity but honestly I expected more bad. The bolt I used has been modified to handle gas better with three holes along the outboard right side above the extractor. The adiosed primer left nothing detectable, which is amazing. I mean I can't find a speck. No damage was done to any of the parts. The firing pin is pristine.

So there you have it; round one. All of these loads no sane person would want to be using for any reason. The highest official published load I could find was a 225 gr. bullet and 45 grs. of 3031. I wish I had a chronograph. The last three loads one could here the grains crunching when I mashed the bullet down! Maybe I could fit 52 gr. in a case but that would be moot at this pint. So now What to do? I think I'm going to fire X more rounds at 49 gr. and unscrew the barrel to check for set back. Then I'm going to feed the same regimen to the '93 Spaniard. Then I'm gonna need some other powder to make things get even more interesting.

Here's a pic of Betsy:

[fouronesix]

I'm still following this thread and so far- very interesting! Actually what you are seeing is what I would have expected with these actions. They are fairly forgiving of out and out burst failure but tend to give a little at a time. While at some point, as you may find with measuring set back, they do "fail" in matters of degree. It is something I noticed with the one absolute torture test I did on the Modelo 1936.
Would be interesting to run the 7x57 load I used through QL (which I don't have). The load was 37 gr Bulleye under 625 gr "projectile".

One thing I see in the latest test with the 3031, maybe?, is that the pressures as predicted by QL may be slightly overstating what is happening in your tests. Seems like loads 1 and 2 should have shown more head expansion and primer flattening at the predicted pressures of 75-85Kpsi. ??? don't know really- what is your take on it?

[shredder]

Been following this as well. Nice work.

Have you measured headspace after firing those loads? I for one would love to know your "before and after" headspace measurements. Looking for lug setback after de-barrelling the action is a good idea as well.

[copperlake]

I'm still following this thread and so far- very interesting! Actually what you are seeing is what I would have expected with these actions. They are fairly forgiving of out and out burst failure but tend to give a little at a time. While at some point, as you may find with measuring set back, they do "fail" in matters of degree. It is something I noticed with the one absolute torture test I did on the Modelo 1936.
Would be interesting to run the 7x57 load I used through QL (which I don't have). The load was 37 gr Bulleye under 625 gr "projectile".

One thing I see in the latest test with the 3031, maybe?, is that the pressures as predicted by QL may be slightly overstating what is happening in your tests. Seems like loads 1 and 2 should have shown more head expansion and primer flattening at the predicted pressures of 75-85Kpsi. ??? don't know really- what is your take on it?

I know nothing about ballistics and even less about Quick Load. I'll leave it to someone else to answer your question more intelligently than me. Just look at what happened between 50 gr. and 51.5 gr. So it may not be too out of whack to not see too much deformation at 49 gr. This is virgin brass. My guess is that running them through dies 5-6 times and we'd have a different story. I have to say I'm impressed by two things; until the primer blew things seemed completely normal and what happened to the primer? Did it vaporize? Away's back a poster suggested to wrap the inside of the torture chamber with cellotex to capture particles, maybe a good idea. As for your test with the Mexican '36 and what QL says, I'd PM DCM, who I profusely thank for his generous donation, and ask him. He'd need to know bullet specifics and COL to figure.

One other thing I noticed after looking at everything more closely is that the bolt face got a nice hot gas torch job during primer removal. Here's a pic, that ring was not as pronounced before. About 90% of the used bolts you find from this era show some erosion.

Oh, yeah, one other detail for those of you that like detail; absolutely dry chamber and bore before testing, swabbed with acetone.



Sadly, this rodeo is going to slow down some because >GASP< I have to go back to work. I build aluminum boats and was between, and now have to get in the front, for the next three months or so. Not that I'm going to stop, just slow down. I talked to the local supply, Kachemak Gear Shed, and have to put in an order for some hotter powder in order to finish the project. In the meantime, I've twisted up some rounds @ 49 gr. that I'm going to fire five in the Swede and unscrew the barrel. Then, fire five in the Spaniard and unscrew the barrel. I'm also intrigued with this blown primer deal. On another thread here I 'modernized' a '95 to handle gas better. I want to intentionally make that happen (blow primers) and see if some of these simple things make them safer.

ALSO, pretty please, if anyone would be so kind as to loan me, or nominally rent me, a 8X57mm reamer to do the next thing, which is to put 8mm bullets through a 7mm barrel so as to continue my channeling P. O., that would be most excellent, or 'awesome,' as my too (and two) grown daughters would say.

I have really enjoyed this project and thank you all so much for being part of it. Remember, if you have something you want to throw in the hat, no matter how wacky,
I'll consider it. In the end these puppies are goin' to heaven