I've worked up a new hunting load using 40.8 grains of H4895 (MAXIMUM load = 40.9 grains of H4895) behind a 150 grain Nosler Ballistic Tip bullet sparked by standard Winchester primers in once-fired & "accurized" Winchester cases. This load seems pretty accurate and has a very consistent muzzle velocity which usually indicates an accurate load. I chronographed this load on two different days and got a consistent average muzzle velocity of 2635 fps on
both days.
11/5/08 - 2638 fps, 2642 fps & 2627 fps for an average MV of 2635 fps. Maximum deviation = 15 fps (+7 fps & -8 fps)
11/6/08 - 2633 fps, 2636 fps & 2636 fps for an average MV of 2635 fps. Maximum deviation = 3 fps (+1 fps & -2 fps)
H4895 is one of Hodgdon's "
Extreme" powders which is reportedly "temperature
insensitive" meaning the powder produces much the same velocity regardless of air temperature.
This is a revolutionary advance in rifle powders since most rifle powders lose some of their "punch" as the air temperature drops.
In extensive experiments with IMR4895, I found that muzzle velocity dropped as much as one foot/per/second for each degree of temperature drop... I.E., I chronographed my hunting load consisting of 41.5 grains of IMR4895 behind a 150 grain Nosler Ballistic Tip bullet sparked by a standard Winchester primer in "accurized" Winchester cases at 85�F & got an average MV of 2685 fps. Later in the year, I chronographed the same load at 35�F and got an average MV of 2630 fps... a 55 fps drop in muzzle velocity with a 50�F drop in air temperature.
This may have been a fluke... but those are the results I got.
The maximum listed load of H4895 (40.9 grains) behind a 150 grain Nosler B.T. averaged 2650 fps, but the standard deviation was larger. Therefore, I choose the load with the smallest velocity deviation which, in my experience, usually indicates "THE" most
accurate load since it is the most
CONSISTENT load... and I've found, as most bench-rest match shooters will tell you, that "consistency" tends to breed accuracy.
Incidentally, I used an overall cartridge length of the standard 2.600 inches to insure smooth feeding through the rotary magazine of my 1953 Model 99 (EG).
Sierra makes very accurate bullets... I am using 140 grain Sierra, flat-based ProHunter bullets to work up accuracy loads in my Ruger #1 International (w/Mannlicher-style stock) in 7x57. They should work just fine in working up accuracy loads... or even hunting loads for deer in your Model 99.
I worked up loads in my Model 99 using IMR4064 and found that as I approached the maximum load, I got "pressure signs" (flatten primers, etc.). In my rifle, 43.0 grains of IMR4064 was DEFINITELY a "maximum load" as was indicated in my loading manual.
Here are my notes made for tests done on 6/17/02.
.300 SAVAGE TEST RESULTS (6/17/02)
(temps 73� to 75�)
VELOCITY RESULTS using IMR4064, Rem.9� primer & Win. Cases
41.8 grains gave a 5-shot average of 2598 fps,
42.0 gr. = 2608 fps,
42.2 gr = 2635 fps,
42.4 gr. = 2628 fps,
42.6 gr. = 2623 fps,
42.8 gr. = 2609 fps
43.0 gr. = 2634 fps. (maximum load)
Accuracy was good with most loads printing (at 50 yards) 3-shot groups of 3/8th inch and 4-shot groups of 3/4th inch. However, there was always one �flier�� and occasionally 2 �fliers�.
Note the unusual variation in these loads wherein more powder yields less velocity with all other components remaining the same. Since this is normally unlikely, it is possible the relatively heavy crushing of powder granules during bullet seating may account for this unusual velocity differential.
CONCLUSION-IMR4064 RIFLE POWDER
The last 5 velocities attained in this test, from 42.2 grains to 43.0 grains are questionable. The 43.0 grain load IS definitely a �maximum load� and yields only 2634 fps. It is a heavily compressed load & this may be the reason for the unusual velocity readings. I doubt that IMR4064 is the best powder for my particular M-99 in .300 Savage caliber. Of course, it�s also possible a different primer (Rem. 9� was used) may yield different results.
PRESSURE INDICATIONS: 6/17/02 (74�)
IMR3031- Using 40.0 grains (max. load), loaded 5 rounds using each of the four different primers after short �work up� to that level. All primers showed some flattening with CCI-Bench Rest & Remington primers showing 95%-100% flattening. Winchester std. Large rifle primer showing about 80% flattening and Federal showing some machine marks and about 60% flattening.
IMR4895(loaded in 1999 using powder purchased in 1995)- At 41.5 grains (max. load) using Remington 9� primer and Winchester cases gave the following velocities in the order of 1 through 5 shots- 2728, 2718, 2696, 2702 & 2692 for an average velocity of 2707 fps. Primers were 80% flattened. These rounds were loaded in 1999 for use in the old M-99 w/22� barrel.
IMR4064- Loaded 5 rounds at each load-level starting at 41.8 grains increasing in .2 grain increments to 43.0 grains. The first 2 of 5 rounds @ 43.0 grains using Remington 9� primers had 100% flatten primers. This is definitely a �maximum load� at 2634 fps average velocity. The last 3 rounds flatten 90% , but still had some �rounding� to them. Next lighter loaded rounds (42.8 grains) showed no flattening of primers. In view of the above information, I'd suggest you try H4895 after you finish your tests with IMR4064. Of course, each rifle is an "individual"... and your results may not be similar to mine.
Strength & Honor...
Ron T.