A-Square data:

49,800 psi = 43,660 CUP
**********

by piezo transducer, assume 70 degrees F, with:

RL-15 80.0 grains, and
*****************
400 grain A-Square Dead Tough soft
**********************************
16.54" RH twist
0.423" groove
6 groove
0.412" bore
0.141" groove width
26" barrel length
velocity was 2379 fps ... may have been one of those old sloppy chambered antiques.

This should be very comparable to my Varget Extreme load with 81 grains powder and 400 grain Woodleigh RNSP. I got 2401 fps at 78 degrees F in my 24" McGowen 10" twist barrel.
This is a 95% load density with the Woodleigh and Varget.

Looking back at an 82 degree F day test of H4350 with the Woodleigh 400 grain RNSP, 87 grains is a 100% load density, and gave 2329 fps in my rifle.

I would have to use a drop tube AND compressed loads if using H4350 or IMR-4381, to achieve what I easily get with 95% to 98% loads of Varget:

81gr + 400 grainer >2400 fps: 95.3% = 50,000 psi (SWAG), surely way less than 55,000 psi
83gr + 380 grainer >2500 fps: 97.6%
87.6gr + 340 grainer >2700 fps: 97.3%

I am way below 60,000 psi on all my loads, by Scientific Wild Assed Guess.

Anyone with any other actual pressure data to add, please do.

Varget and RL-15 which need no compression nor drop tubes is especially interesting.

To Alf, I ask him to analyze the A-Square pressure in PSI with his internal ballistics program and see how far off his program is from A-Square pressure data.

I plan to keep this conversation with myself alive forever.

btt

Same A-Square data source as post above:

45,600 psi
**********
86.0 grains of H4350
********************
400grain Dead Tough
********************
Velocity in same rifle as first post = 2221 fps.
They must have been using the old slow H4350. The new Extreme version is faster, and would give higher pressures and velocities. Seems they just stopped around 99% load density.

Changing powder specs over the years, and even lot to lot variations in the same time-neighborhood, make these comparisons need interpretation.

Great information keep it comming. Do you have any data for 10.75x68?????

lb404,
I am hoping "sumbuddy who know" will add some 10.75x73 (and 10.75x68 if you wish) pressure data to this thread. All I have is the A-Square manual data.

Maybe Alf will post some pressure data for the .404 Jeffery. He gave some 350 grain X-Bullet pressures once, IIRC, but I have lost track of it. Maybe he has some more?

btt
Chamber pressures of .404 Jeffery ammo please,
sumbuddy who know?

RIP,

Are you getting sticky extraction, flat primers or brass flow?

Ron,

What exactly do you want, simulation data or real data measured off of a rifle's barrel?

Simulation data is cheap and easy, the other isn't .

ASS_CLOWN

quote:

Originally posted by 500grains:
RIP,

Are you getting sticky extraction, flat primers or brass flow?

500grains,
I am getting none of the signs or symptoms you list. I am just getting poo-poo-ed for shooting higher velocity, lighter bullet loads in my .404 Jeffery. I think my Varget loads are fine, don't want to change anything.

quote:

Originally posted by ASS_CLOWN:
Ron,

What exactly do you want, simulation data or real data measured off of a rifle's barrel?

Simulation data is cheap and easy, the other isn't .

ASS_CLOWN

AC,
We have already proved that the computer generated velocities and pressures are BS. Real measured data only please, and even that is fraught with calibration issues, etc.

As a side note, with woodleigh 400 grain WeldCore RNSP's, seated and crimped on cannelure, I found 100% load density to be:

Varget Extreme: 85 grains
H4350 Extreme: 87 grains

With the North Fork 380 grain SP seated and crimped as deeply as possible, 100% load density was:

Varget Extreme: 85 grains

With the North Fork 340 grain SP seated and crimped as deeply as possible, 100% load density was:

Varget Extreme: 90 grains

That's where the shaking and rattling stops.

Bullet length was 1.254" with the 340 grainer, and 0.550" of it is seated into the case. 3.554" is the COL. Brass trim-to length is 2.860".

If anyone wants to run some numbers for laughs, I welcome it, as long as it is a program other than "Load from a Disk" or "AccuLoad," as they are looney tunes on this issue with the 340 grain .423. They go into default errors on case capacity, etc.

Use a case capacity of about 114 to 115 grains grains water please.

RIP,

All this data you've collected; does this mean your .404J will kill stuff?

regards,

Pete

quote:

Originally posted by Pete E:
RIP,

All this data you've collected; does this mean your .404J will kill stuff?

regards,

Pete

Very funny, ass wipe. It has only killed one bison so far, but I am itching to try it out on anything that comes along.

Actually there is very little real pressure data on the .404 Jeffery. That is what I am looking for.

RIP,

I was talking to a chap in our hunting club about 9.3x62 loads the other week, and he mentioned pressure testing.

It seems one of the ammo makers in the UK will test fire and take pressure readings ect of your homeloads for around $5 per round...I think you can get the same thing done at the Birmingham Proof house too...

You must have similar facility's in the US? You could ship off a couple of rounds in say three or four different loadings and get all the data you need...

Regards,

Pete

RIP,

You might want to take a look at the Birmingham Proof House website at:
http://www.gunproof.co.uk/

It would seem that for a "small charge", they will research a given firearms related subject in their records/library and forward you any information they hold.

You would think they should know a thing or two about the .404J although it may be more related to the older factory loadings rather than homeloads...

Regards,

Pete

Pete,
That is an interesting link. I will be looking around on my side of the pond. I need to visit A-Sqaure and see if I could coax them into testing the Varget loads in .404 Jeffery. How good a customer of theirs would I have to be for that to happen? "I'll buy a T.Rex Hannibal if you will test these 10 rounds of ammo for me???"

I have some 10.75x68 loads but the only pressure data I have is on the 401 gr. 10.75x68 RWS factory round at 2200 FPS and it operates at 36,000 PSI....I thought that impressive...my source is Rifle No. 134, march/April 1991....

The articale gave some interresting load information:

RWS FMJ 401 gr.
74 grs. WW-748 2208 FPS
56 grs. IMR-4198 2140 FPS

347 RWS SP
58 grs. IMR-4198 2411
60 grs. AR-2207 2404

AR-2207 is the same as IMR-4198

I substituted 350 gr. Woodleigh .404 bullets for the above and got the same results and these loads were mild to the extreme....A load of 74 grs of IMR-5350 gave me 2109 FPS and recoil of a 30-06 it seemed to me...very nice.

If the 10.75x68mm Mauser can do that, think how low the pressures mut be in the 10.75x73mm/.404 Jeffery for the original 400 grainers at 2150 fps.

Thanks Ray. I will go back and look through the "10.75mm Alternative" article. Your data will add some interest to this thread. Now where is Alf's actual pressure measurement data for the .404 Jeffery?

I am glad I was goaded into trying the .404 Jeffery by Ray and Mickey and Alf being the primary promoters here. It is now one of my favorite rifles.

The 340 grain North Fork at 2700 fps, with Varget 87.6 grains, shot into 0.554" for three shots at 100 yards, and just over 2" for three shots at 300 yards. The scope is set for 3" high at 100 yards, and dead on at 225 yards, and low by 7.75" at 300 yards.

A second scope and peep sight will be set for dead on at 100 yards with the 380 grain North Forks.

One amazing thing with this rifle of mine is that it shoots the 340 grainers at 2710 fps to the same POI as the 380 grainers at about 2530 fps, at 100 yards, so the same scope or peep could be used with both bullets and be dead on at 100 yards, if so sighted.

This is a very happy occurrence. 3" high is a little too much at 100 yards.

btt
Calling all .404 Jeffery Pressure Measurements, and 10.75x68 too.

I broke down and ordered a .404 reamer today.

lawndart

RIP

You DO know (or I hope you know) that a pressure test of your load in any other gun, has very little meaning. A moderately stout load in my gun turned out to be a mouse fart load in yours. I could test it, lawndart could test it and it still wouldn't mean whether it was safe or unsafe in yours or anyone else's gun. I do wish folks would get off this "powder charge equals pressure" fantasy becasue it just isn't so. There are just too many variables. The only thing a pressure test MIGHT tell is whether it is possible to reach a certain velocity with a certain powder. If it does tell that, that is as good as your are going to get. Short of equiping your own gun, you will never know exactly what is happening inside of it.

Mike

.

quote:

Originally posted by NFMike:
RIP

You DO know (or I hope you know) that a pressure test of your load in any other gun, has very little meaning. A moderately stout load in my gun turned out to be a mouse fart load in yours. I could test it, lawndart could test it and it still wouldn't mean whether it was safe or unsafe in yours or anyone else's gun. I do wish folks would get off this "powder charge equals pressure" fantasy becasue it just isn't so. There are just too many variables. The only thing a pressure test MIGHT tell is whether it is possible to reach a certain velocity with a certain powder. If it does tell that, that is as good as your are going to get. Short of equiping your own gun, you will never know exactly what is happening inside of it.

Mike

Agreed. I am satisfied that my loads are not excessive in my rifle.

And your .423/340 grain soft point will surely deliver the mail.

Thank you Mike Brady, Bullet Maker Extraordinaire.

Still, if anyone comes across any pressure data, it would sure be interesting, to demonstrate just how low the pressures are in the .404 Jeffery.

So I have to fit my own rifle with a strain guage to mean anything. I am back to watching brass as my strain guage, ala Mike375. So far no problems.

And of course lot-to-lot variation of powder is another fly in the ointment, along with rifle-to-rifle variation.

I have headspace guages too, to watch for any changes with the no-go guage.

So far looks good in my rifle:

Varget 81 grains with 400 grainers >>> 2400 fps
Varget 83 grains with 380 grain NF's >>> 2500 fps
Varget 87.6 grains with 340 grain NF's >>> 2700 fps

These are mild loads in my rifle. Back to brass.

.

quote:

Originally posted by ALF:
FNMIKE:

" Powder charge equals pressure fantasy" "Cause it isnt so"

Sorry Mike but maybe you should wish to retract that statement cause it is flat wrong !

Alf,

I think you are misinterpreting what Mike said.

A given powder charge may cause a pressure problem in my rifle but not in yours. So there is not necessarily any particular powder charge that can be considered safe or unsafe because of the different pressure results we see with the same load in different rifles.

For example, in a .338 Win mag, I use a 250 grain Sierra over 76 grains of H4831. NO PRESSURE SIGNS AT ALL. But any loading manual will say that I am off the deep end.

Likewise, I use 80.0 grains of H4831 in a 7mm STW behind a 140 grain ballistic tip. No pressure issues, but the reloading manuals differ with me.

Part of it is that I use match grade barrels, so the friction of the bullet moving down the bore is less than if I were using a R700 or a Savage 110.

Part of it might be that I am shooting these loads at high elevations.

But it would be wrong to conclude that I have a pressure problem just because my loads are off the deep end per the reloading manuals.

Ron,

Here is what my simulation results are for your loads.

400gr bullet, 87gr of H4350
Your MV = 2329 fps (from your data)
Chamber pressure = 45560 psi (max avg)

340 gr bullets, Varget loads as follow:

85gr Varget
MV = 2622 fps (your data)
Chamber pressure = 54273 psi (max avg)

86gr Varget
MV = 2654 fps (your data)
Chamber pressure = 55605 psi (max avg)

87gr Varget
MV = 2683 fps (your data)
Chamber pressure = 56826 psi (max avg)

88gr Varget
MV = 2709 fps (your data)
Chamber pressure = 58085 psi (max avg)

89gr Varget
MV = 2740 fps (your data)
Chamber pressure = 59544 psi (max avg)

90gr Varget
MV = 2768 fps (your data)
Chamber pressure = 60862 psi (max avg)

ASS_CLOWN

Ditto 500grains.
My McGowen barrel has wide grooves and narrow lands, is .423 in the grooves, and the lands look to project the normal amount about .010".
I am sure it would be a low friction barrel, as 500 grains is saying, even though it is a 10" twist stainless. It sure works well with the grooved North Forks, which might reduce friction further over a solid bearing surface bullet. I cleaned it after 40 rounds last time and had almost no copper fouling. It looked clean before I cleaned it, and the wipe out produced only a trace of blue copper color, mostly just the black of powder fouling.

quote:

Originally posted by ASS_CLOWN:
Ron,

Here is what my simulation results are for your loads.

400gr bullet, 87gr of H4350
Your MV = 2329 fps (from your data)
Chamber pressure = 45560 psi (max avg)

340 gr bullets, Varget loads as follow:

85gr Varget
MV = 2622 fps (your data)
Chamber pressure = 54273 psi (max avg)

86gr Varget
MV = 2654 fps (your data)
Chamber pressure = 55605 psi (max avg)

87gr Varget
MV = 2683 fps (your data)
Chamber pressure = 56826 psi (max avg)

88gr Varget
MV = 2709 fps (your data)
Chamber pressure = 58085 psi (max avg)

89gr Varget
MV = 2740 fps (your data)
Chamber pressure = 59544 psi (max avg)

90gr Varget
MV = 2768 fps (your data)
Chamber pressure = 60862 psi (max avg)

ASS_CLOWN

AC,
That looks like a good approximation of my reality. How did you do that? Thank you very much.

Ron,

I use a combination of thermodynamics, rectilinear motion, and empirically derived pressure curves. For powders that I do not have pressure curves for I 'guess' from relative burn rate charts.

I hope the data was helpful to you. I have found that the commercial programs all suck to lesser or greater degrees. Therefore, I haven't been convinced to part with any of my money for them (besides I paid considerably more money to get trained to perform this type of analysis anyway).

By the way, if we assume a standard deviation of chamber pressure equal to 7.5% of the average peak pressure then your worse case load (90 gr of Varget and a 340 gr NF) would provide a maximum achievable 3 Sigma pressure of 74556 psi. If the SD was increased to 10% the maximum achievable 3 Sigma pressure would be 79121 psi.

The 3 Sigma values would be considered maximum individual pressure readings. 3 Sigma distribution means that 99.7% of your individual pressure readings would fall between the +3 Sigma and -3 Sigma values of individual pressure.

Just a little more information to muddy the waters.

ASS_CLOWN

quote:

Originally posted by ASS_CLOWN:
Ron,

I use a combination of thermodynamics, rectilinear motion, and empirically derived pressure curves. For powders that I do not have pressure curves for I 'guess' from relative burn rate charts.

I hope the data was helpful to you. I have found that the commercial programs all suck to lesser or greater degrees. Therefore, I haven't been convinced to part with any of my money for them (besides I paid considerably more money to get trained to perform this type of analysis anyway).

ASS_CLOWN

And you swear this is not imagineering? Way over my head!

Before I call I wish you would explain it a bit more.

Ron,

I have found that my approach works better than the simple generic expansion equations apparently used by many software programs.

In cases where the bullet ballistics are known, such as your case, I calculate the MEP (mean effective pressure) to achieve the claimed bullet ballistics. I then calculate the throttle of the case (404 Jeffery in this case). The burn rate of the powder is directly effected by the case throttle effect. I have peak pressures for various case throttles, and I then compare the case under analysis to the data base to acquire a peak average pressure multiplier. The peak averagae pressure multiplier is then applied to the MEP to achieve the peak average chamber pressure of the case under analysis.

It is done differently if I do not know the bullet's ballistic performance, but only the powder charge, bullet weight, bore diameter, and barrel length.

Now call 'BS' all you want. I was only offering the data for what it is, it won't even get you a cup of coffee anywhere I know of.

ASS_CLOWN

AC,
That sounds real to me, and it is beyond my ability to comment any further. I could dig it but it would take some work. You are not an imbecile, of course, but I feel like one for looking the gift horse in the mouth. Thanks again.

Rip,

Just ship the rifle out here for a month. I'll put the strain gauge (it measures.4 x .8 cm + small wire leads) on the bottom of the barrel where no one can see it. I'll run your favorite loads through the computer chips and will send you a lovely print out of the pressure curves. I'll even find a Grateful Dead stick to put on the stock.

lawndart

Ron,

I wasn't upset so don't feel bad (this is a simulation afterall). If you let John strain gage your rifle and shoot your loads, I would appreciate it if you would share the pressure trace data. I would add it to my data base for future reference. I currently do not have any actual pressure curve data for a 404 Jeffery, so I estimated it for your loads based off of cartridges with similar throttles but different bore efficiencies (read potential for some small error).

You are most welcome, by the way.

ASS_CLOWN

AC,
Cartridge "throttle" is new terminology to me. Can you elaborate on that a bit please? I'll certainly get back to you with any pressure data on this rifle. Thanks.

lawndart,
Shipping my rifle off for a month would be too traumatic. I will have to look into the Oehler pressure setup. Everybody ought to have one. Thanks anyway.

Ron,

A throttle is basically a flow restriction. In a bottlenecked case (the only ones with throttles) the throttle is dictated by the dimensions of the shoulder area. The throttle speaks directly to how quickly the pressure rise occurs for any given powder in a particular case.

ASS_CLOWN

.

Alf,

I suspect what you are calling MBP is the same thing that I am calling MEP (that is an engine term, so I guess my background is showing).

What I have for Varget is a MEP to Chamber pressure multiplier of ~ 2 for the 404 Jeffery (roughly the same as 4831 in an 06). This is for MEAN pressure. As I stated in an earlier post depending upon what the standard deviation is the actual maximum individual chamber pressure could be MUCH higher (easily 79,000 psi). Strangely that is is ~ 18,000 psi higher than my calculated mean or average max chamber pressure. I would also note that since I have no direct data to correlate the model to an actual 404 Jeffery, that the model could be off by 5% to 10% quite easily.

No simulation is ever perfect, Alf. If mine is wrong I am sorry, the error was not done intentionally, and one referencing simulations data MUST ALWAYS REMEMBER THAT IT IS SIMULATION DATA NOT, I REPEAT NOT, REALITY . (Bold face caps for emphasis not to indicate yelling).

I wonder if there is a little statistical margin in those programs.

I stopped using them when I strain gaged several rifle barrels and routinely got higher muzzle velocitied for any given chamber pressure. I strongly suspect that the math models in commercial software have been massaged just a tad to save the reloader from himself, if you get my drift.

By the way, I am not saying it is ok for Ron to overload his 404 Jeffery (relative to CIP pressure specifications). He is a grown man and from all accounts an experienced handloader, so I figure he knows the risks.

I have loaded a 416 Rigby to over 2850 fps with a 340 gr Woodleigh. Pressures measured in the upper 60s, IIRC.

I can do the stress calculations on the Norma 404 Jeffery case if you supply the dimensions you referenced. If it is anything like the Norma 416 Rigby though, it is MIGHTY strong.

The elastic properties of C26000 cartridge brass are:

Young's Modulus = 16E6 psi
Poisson's Ratio = 0.34
Rupture Modulus = 6E6 psi

Tensile strength of H06 = 65,000 psi
Tensile strength of H02 = 52,000 psi
Tensile strength of H01 = 40,000 psi

Volumetric expansion ratio is a major contributor and is helpful to select an appropriate burn rate powder. However, I find that it os somewhat lacking in accuracy when you introduce the bottle necked cartridge. The bottle neck does precisely what it's name implies, it creates a back pressure, which is not comprehended by the overly simplistic volumetric expansion ratio. Therefore, it is my contention that by introducing the throttle effect into the equations the pressure calculations become more accurate.

ASS_CLOWN

.