Powder efficiency for energy created(my findings with my research in developing hunting loads for my rifles)

[bitbythebug]

I have been hunting and reloading for 50+ years and got smitten with the long range bug about 10 years ago. One of the first things you discover is the need for precise accuracy. I thought, at first, that all I needed were good new scopes, because I had hunted successfully for 40+ years before that with the 3-9 V-X Leupold's that I had. The good scopes quickly illustrated how inadequate the rifles I had been using were. They would hit something at 300-400 yards but, after range testing them, was amazed that I had ever hit anything longer than that. They weren't very accurate. But was it the gun or were my reloads to blame. So the quest began. Finally, 7 custom rifles later and many months at the range, I had the tack-drivers that were required and life is now good. Now, though, being 73 and Idaho having no mule deer left, I have slowed down. I still take the horses into the back country and enjoy what God has given to all of us. I still shoot and reload.
I noticed, going through my shooting notes, that my 300 Win mag with either the 210 Nosler long range accubond or the Hornady 212 ELD-X, came very close to the ballistics of my 300 Ultra mag shooting the same bullets. However , the 300 Win mag did it on 16 grains less powder. I gained much respect for that cartridge and I wondered what other rounds were as efficient in producing not only velocity but down range energy efficiently. I went back over my notes and compiled this list comparing how much energy was produced with every grain of powder. I know it is basically meaningless but it was interesting to me and I thought it might be interesting to others.

Powder Energy Efficiency Most Energy Created by 1 Grain of Gun Powder in my hunting rifles​
Cartridge	Bullet	weight	G1 B/C	Powder	Grains	Muzzle Velocity	1000 yard Velocity	Muzzle Energy	1000 yard Energy	Energy per Grain@1000yds	Figured @ 6000'
243 Win	Berger VLD Hunting	105	.545	RL-23	43.5 gr.	3050 avg.	1792	2169	748	17.2 lbs. per Grain of powder	26" barrel
264 Win Mag	Hornady ELD-X	143	.623	RL-33	76 gr.	3200 avg.	2042	3251	1324	17.42 lbs. per Grain of powder	26" Barrel
7mm STW	Hornady ELD-X	175	.689	WC-857	90 gr.	3210 avg	2148	4004	1793	19.92 lbs. per Grain of powder	26" Barrel
30-06	Hornady ELD-X	212	.663	Unknown Powder	57.5 gr.	2708 avg.	1724	3452	1399	24.33 lbs. per Grain of powder	24" barrel
300 Win Mag	Hornady ELD-X	212	.663	RL-26	74 gr.	2970 avg	1925	4152	1745	23.58 lbs. per Grain of powder	26" Barrel
300 Ultra Mag	ELD_X Nosler LRAB	212 210	.663 .661	RL-25	90 gr.	3050 avg.	1987	4379	1859	20.62 lbs. per Grain of Powder	26" Barrel
338 Ultra Mag	Nosler LRAB	265	.778	RL-25	90	2855 avg.	1971	4796	2285	25.39 lbs. per Grain of powder	26" Barrel

All ballistics listed were shot by me with my guns at my private range at 5860' above sea level.

• The velocities were gathered using a Magneto Speed and shot through a Caldwell chronograph mounted on a tripod 15' away from the barrel. There was an average of 10-20 fps difference between the two but attributed it to the distance out of the barrel to the Caldwell. They were always close and I used both just to check for anomalies.
• All of these loads were developed after years of testing and thousands of rounds and several new barrels in my guns. They should not be viewed as proper loads for your guns and should be approached very carefully. I pressure test all my loads before I chrono and shoot for accuracy. All of these loads are very accurate IN MY GUNS. They may be terrible in yours.
• I did this just to see what caliber utilized powder most efficiently. I got to wondering after noting that my 300 Win mag got nearly the same velocities as the 300 RUM on 16 grains less powder.
• Most efficient (from best to worst) Keep in mind these are only my guns. I am not drawing any conclusions other than from my guns.
• 338 Ultra mag-25.39 2) 30-06 – 24.33 3) 300 win mag – 23.58 4) 300 RUM – 20.62 5) 7mm STW – 19.92 6) 264 Win mag – 17.42
• The surprising part to me was that the 30-06 was very efficient (as expected) but very respectful in 1000 yard retained energy (which wasn't expected). Hope this is interesting if not helpful to others.

The Chart attached weird. I hope you can make sense of it. Also the unknown powder is a five pound jug that was given to me but all markings were lost. I started testing with it and it was great with some cartridges(243,30-06 especially). I wish I knew what it was, sorry. RL 22 and Superformance come very close to it in the 30-06.