03 July 2009, 18:45
lawndartHi Mike,
I think I have some MRP loads that should be close to the H4831SC. Don't put yourself to any trouble, but if you run into those loads during the normal course of your days, feel free to e-mail me@ johnnoak@cableone.net, or just fax them to 208 337 3262.
I'll fiddle around with length, crimp and pressures at 3.6"
I'll likely offer something slower with Woodleighs at the shorter lengths for M-98 conversions.
BTW, I'm doing a switch barrel on a Model 70 Classic. I'll either use the 7mm STW or the 300 RUM depending on wich magazine and follow work best with the basic 404 Jeffery case. Oh yeah, the other barrel will be a 9.3 x 70mm. It is just a Jeffery case with the neck squeezed down. It only requires one pass with Redding dies.
Just something on the "to do" list.
Thanks,
LD
Bro' Lawndart,
If you can get any pressure readings with the 404 Jeffery, you will be a real scientist!
I am especially interested in what you might get with Varget, and what barrel you will be using.
My favorite 404 Jeffery load:
Norma brass
F215 primer
380-grain soft: "Original Mike Brady North Fork Lion Fang (NFLF)"
.423/380-grain SSP
COL 3.590": works fine in the M70 box from a 300RUM Winchester.
83.0 grains of Varget Extreme
Muzzle Velocity = 2526 fps at 83 degrees F
average of 6 shots chronographed
sd = 5.5 fps
3/4 MOA accuracy is routine
24" barrel
Beware of different makers' barrels, with groove diameters that vary
from .4226" for Lothar-Walther
to .424" for Krieger.
Other aspects of land/groove configurations vary also.
Variations in twist between 10" and 14" have negligible influence on pressure and velocity,
but the groove diameter differences and land bearing surface are more significant.
My barrel is a McGowen stainless with 1:10" TWIST, 24" long, and it is looser than Mike's Lothar-Walther, it seems.
Any of the barrels will work wonders with Varget. Just start low and work up, and stop where you want.
Saeed used a tight LW barrel (IIRC) and Varget, and got results in velocity faster than mine.
I have looked for his postings of that in the past, could never find them again.
I think he deleted them out of pressure concerns.
Another sweetheart load in my rifle is: 340-grain North Fork SSP
87.6 grains Varget >>> 2706 fps MV at 54 degrees F.
COL = 3.554" with the stubbier bullet.
Other components same as above.
At 100 yards, that one shoots 3 shots into 0.557".
At 300 yards, 3 shots into 2.126" (Maybe I flinched?).
Varget is great with the 400-grain Woodleighs (RNSN),
other components same as above,
Varget chronograph results:
72 grains >>> 2125 fps MV (Classic 24" barrel stuff)
75 grains >>> 2233 fps
77 grains >>> 2275 fps
79 grains >>> 2336 fps
80 grains >>> 2360 fps
81 grains >>> 2401 fps
82 grains >>> 2428 fps
83 grains >>> 2462 fps
84 grains >>> 2490 fps
All above 400grRNSN Woodleigh loads were 3-shot chronograph averages.
However the 81.0 grain load of Varget with 400-grain Woodleigh RNSN did stand out: only a 6 fps extreme spread, sd = 3 fps, for the miniscule sample of 3 shots.
The 83.0 grain charge gave 30 fps extreme spread and sd = 15 fps for the miniscule sample of 3.
I stop at 81.0 grains of Varget for the 400-grain RNSP, 80 grains for the 400-grain FMJ, Woodies.
I stop at 83.0 grains of Varget for the 380-grain "North Fork Lion Fang" bullet
(NFLF),
and
87.6 grains of Varget for the 340-grain "North Fork African Sheep" bullet
(NFAS),
not quite a full case load, still a little shake.
There is never any compression required with Varget, never a need for a droptube.
For the "classic" low velocity load, just add enough Dacron fluff to lock the powder in place, no shake.
That will uniform the load and might then require only 71 grains of Varget to get 2125 fps classic 24" MV.
Lesser amounts of Dacron can be used as the powder charge is increased.
Just like RL-15 in a Nitro Express.
Varget and Dacron filler worked wonders in lb404's 500 Jeffery too.
That load will definitely get tried in the 500 Mbogo, since all 500 Jeffery load data is directly applicable to the 500 Mbogo, which is of similar case capacity and a better-designed cartridge.

Some folks think they get better results with RL-15 than Varget.
They will, however, get about double the velocity/temperature variation with the RL-15. Still O.K., just expect it.
RL-15 is a fine powder.
Very close to Varget.
80 grains of RL-15
was equivalent to
81 grains of Varget
in my testing
of the 404 Jeffery
with 400-grain Woodleigh RNSP.
Both gave about 2400 fps.
Both are good powders, and the RL-15 has midrange temperature sensitivity, good enough.
Varget Extreme has the least temperature sensitivity, best in that regard.
For an M70, no worries about pressure.
For an antique on an opened-up standard M98, use the classic ballistics of 400-grainer at 2125 fps from a 24" barrel.
Using the Varget or RL-15 loads with Dacron filler will allow that with minimum recoil,
so as to be gentle on the termite food.
That would be around 70 to 72 grains of RL-15 or Varget.
14 July 2009, 09:14
lawndartYep,
No need to touch the bolt face. Call up the Browning/Winchester parts shop just south of St. Louis. Order both the 300 RUM and 7mm STW followers and springs. Also get a spring or two from Jim Wisner. Play "Mix and Match" until you get the feeding as good as can be done short of sending $18,000.00 USD to D'Arcy Echols.
We'll offer a "traditional" load @ 2,125 - 2,150 with Woodleigh bullets. That will be for opened up modelo 98s. The "modern" load will be with North Forks matched soft and flat nosed.
I like the idea of Varget, and may even use that in my 416 Remington Magnum loads at 2,350 fps.
FWIW It is looking like Dacron, gray foam (a la Kynoch/Kynamco) and Puff-Lon all provide the same results.
Dacron is easiest for home loads, cheapest as well.
Puff-Lon just needs the correct Lee scoop.
Foam is regulated by the thickness of the original sheet that you cut your plugs from. One piece will work over a wide range of compressions.
I appreciate the feedback on the various barrel brands. I will make sure to get a true .323" barrel for test work. That is what the NFs and Woodleighs were designed for.
Thank you all for your help!!
LD
PS The specified barrel length for measuring 404J pressures and velocities is 24".