What makes a cartridge efficient
- Thread starter calgarycanada
- Start date
There goes the sticker statement on the car I just got . Thanks Larry
Thanks dkhunt14. This exactly was my question and reasonings behind it.
"Cartridge efficiency is defined as:
velocity - per powder weight, at a given bullet weight:
another variable that could enter into the problem is how much pressure a case is rated for."
Does the type/brand of powder have anything to do with cartridge efficiency,
If ALL aspects of the Load/case/componets are kept the same, except powder type?
Tia,
Don
velocity - per powder weight, at a given bullet weight:
another variable that could enter into the problem is how much pressure a case is rated for."
Does the type/brand of powder have anything to do with cartridge efficiency,
If ALL aspects of the Load/case/componets are kept the same, except powder type?
Tia,
Don
Exactly, the car I can easily tell you why(won't go in details).
It's like one 1.5 litre engine produces 120 horsepower and another 3 litre engine produces 180 that to me means 3 litre engine is not as efficient. The reasons behind that are well understood and 3 litre engine can be built to produce 240 horsepower.
But in case of cartridges there is no explanation out there and so we don't know how to make bigger cartridges more efficient.
dmoran
Donovan Moran
The OP's subject and thread topic is "Cartridge Efficiency". While cartridge efficiency can point to inherent accuracy, powder burn characteristics, and potential ballistic capability, it is not linear or direct correlation to target accuracy. It tells us with a given weight bullet and a given powder energy level, the internal cartridge efficiency of the combination.
Even with in a same cartridge, it can tell us what combinations have more efficiency, with probability to inherent accuracy potentials. Example:
<> 6Dasher / 105-Hybrid / RL-15 at 33.0 / 3000-fps = 56.5% efficiency
<> 6Dasher / 105-Hybrid / H4350 at 36.0 / 3000-fps = 51.8% efficiency
*Comparison = 4.7% efficiency advantage to RL-15 over H4350
Target accuracy comes from an entire shooting system, not singly by cartridge efficiency probability.
My 2-Cents
Donovan
Even with in a same cartridge, it can tell us what combinations have more efficiency, with probability to inherent accuracy potentials. Example:
<> 6Dasher / 105-Hybrid / RL-15 at 33.0 / 3000-fps = 56.5% efficiency
<> 6Dasher / 105-Hybrid / H4350 at 36.0 / 3000-fps = 51.8% efficiency
*Comparison = 4.7% efficiency advantage to RL-15 over H4350
Target accuracy comes from an entire shooting system, not singly by cartridge efficiency probability.
My 2-Cents
Donovan
Donovan, I couldn't think of any better word then efficiency.
I didn't limit efficiency with any one powder. You are right Dasher+105s+RL 15 is more efficient in your example but now compare that combo with
243AI + 105s + any powder available today
Efficiency (lack of word) drops significantly. In 243AI we are using lot more powder(again any powder) to get relatively small gain in velocity.
I didn't limit efficiency with any one powder. You are right Dasher+105s+RL 15 is more efficient in your example but now compare that combo with
243AI + 105s + any powder available today
Efficiency (lack of word) drops significantly. In 243AI we are using lot more powder(again any powder) to get relatively small gain in velocity.
dmoran
Donovan Moran
calgarycanada -
From 1998 until 2004 I used 243 and 243-AI's for LR. Then in 2004 I switched to a 6Dasher, in part for those very reasons you point out. It's efficiency gains is why it can create velocity of similarity to many larger 6mm/243 cartridges. That efficiency advantage points to probability of inherent accuracy, and no doubt why it has proven itself well to target accuracy and LR capability in comparison.
I know I was a believer instantly.... lol
I see the same thing with the 300-WSM in comparison to other 30-cal Magnums.
Donovan
From 1998 until 2004 I used 243 and 243-AI's for LR. Then in 2004 I switched to a 6Dasher, in part for those very reasons you point out. It's efficiency gains is why it can create velocity of similarity to many larger 6mm/243 cartridges. That efficiency advantage points to probability of inherent accuracy, and no doubt why it has proven itself well to target accuracy and LR capability in comparison.
I know I was a believer instantly.... lol
I see the same thing with the 300-WSM in comparison to other 30-cal Magnums.
Donovan
IMHO
I would not call it "cartridge efficiency",
but would instead call it "Ballistic Efficiency",
which requires the careful consideration of the whole package being used,
case capacity,
powder type/brand,
bullet weight,
barrel length,
case psi values etc.
As Donovan has shown, powder types can change Ballistic Efficiency,
All the below have the same bullet weight, same bbl length and,
use 2 different powders and have the same chamber pressure,
and same case size.
Norma 123 powder results,
17 cal-29 gr bullet@ 21000 psi-22" bbl= 1841 fps= 2.85 grs of powder = 40.0% ballistic efficiency,
20 cal-29 gr bullet@ 21000 psi-22" bbl= 1964 fps= 3.94 grs of powder = 33.7% ballistic efficiency,
22 cal-29 gr bullet@ 21000 psi-22" bbl= 2098 fps= 5.07 grs of powder = 29.2% ballistic efficiency,
Bullseye powder results,
17 cal-29 gr bullet@ 21000 psi-22" bbl= 1477 fps= 1.21 grs of powder = 47.1% ballistic efficiency,
20 cal-29 gr bullet@ 21000 psi-22" bbl= 1685 fps= 1.63 grs of powder = 45.5% ballistic efficiency,
22 cal-29 gr bullet@ 21000 psi-22" bbl= 1878 fps= 2.12 grs of powder = 44.5% ballistic efficiency.
Tia,
Don
I would not call it "cartridge efficiency",
but would instead call it "Ballistic Efficiency",
which requires the careful consideration of the whole package being used,
case capacity,
powder type/brand,
bullet weight,
barrel length,
case psi values etc.
As Donovan has shown, powder types can change Ballistic Efficiency,
All the below have the same bullet weight, same bbl length and,
use 2 different powders and have the same chamber pressure,
and same case size.
Norma 123 powder results,
17 cal-29 gr bullet@ 21000 psi-22" bbl= 1841 fps= 2.85 grs of powder = 40.0% ballistic efficiency,
20 cal-29 gr bullet@ 21000 psi-22" bbl= 1964 fps= 3.94 grs of powder = 33.7% ballistic efficiency,
22 cal-29 gr bullet@ 21000 psi-22" bbl= 2098 fps= 5.07 grs of powder = 29.2% ballistic efficiency,
Bullseye powder results,
17 cal-29 gr bullet@ 21000 psi-22" bbl= 1477 fps= 1.21 grs of powder = 47.1% ballistic efficiency,
20 cal-29 gr bullet@ 21000 psi-22" bbl= 1685 fps= 1.63 grs of powder = 45.5% ballistic efficiency,
22 cal-29 gr bullet@ 21000 psi-22" bbl= 1878 fps= 2.12 grs of powder = 44.5% ballistic efficiency.
Tia,
Don
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Alex Wheeler
Site $$ Sponsor
I think some of what we see is pressure holding ability. Theres no free lunch and I am sure we are running these dashers at a much higher pressure than a 243 case would take.
jds holler
Gold $$ Contributor
I think any talk of efficiency must be tied to "intended purpose". If you need to shoot iddy biddy groups at fifty yards, 22 LR is ideal, and anything more powerful would be considered inefficient. Stretch that range to a hundred yards, and the 22 doesn't become simply inefficient, but insufficient. You better step up to one on the moderately powered centerfire cartridges and debate their merits of efficiency.
Comparing ALL CARTRIDGES for efficiency seems unrealistic unless you narrow the purpose/use to smaller parameters.
A Freightliner truck rolling down the interstate at sixty five MPH, with a 45,000 lb. payload is pretty efficient; take away the 45,000 lb. load, (it's intended purpose), and it's damned inefficient. jd
Comparing ALL CARTRIDGES for efficiency seems unrealistic unless you narrow the purpose/use to smaller parameters.
A Freightliner truck rolling down the interstate at sixty five MPH, with a 45,000 lb. payload is pretty efficient; take away the 45,000 lb. load, (it's intended purpose), and it's damned inefficient. jd
.243 Winchester with 100 grain bullet and 49.0 grains of powder @2980 fps = 50 ft lbs of energy per grain of powder.
.308 Winchester with 150 grain bullet and 41.3 grains of powder @ 2887 fps = 67 ft lbs of energy per grain of powder.
The .243 produces more velocity, but the .308 produces more energy per grain of powder, while using a smaller amount of powder, which shows it's efficiency.
.308 Winchester with 150 grain bullet and 41.3 grains of powder @ 2887 fps = 67 ft lbs of energy per grain of powder.
The .243 produces more velocity, but the .308 produces more energy per grain of powder, while using a smaller amount of powder, which shows it's efficiency.
You are right but I'm not comparing two different calibers here.
I'm only trying to compare two different cartridges using same bullet with any powder and why one cartridge can launch same bullet - at same pressure-at similar velocities with less powder.
Please read all my posts above, as I tried to make myself as clear as possible.
Yep, to make any test comparing the Dasher case to a 243AI case would need the 243AI case to have been fire formed from Palma brass... Then you have a test..
It still would take more powder to get the same speed as a Dasher. Yes you could get more top end but it takes a lot more powder to do it. Matt
6.5x284 and 6.5x55 improved. The 6.5x55 improved easily equals the velocity of the 6.5x284, using less powder and operating at substantially lower C.U.P. Operating at lower pressure and burning less powder for equal velocity and energy = efficiency.
Edit: both cases using the same weight bullet.
Another example is the 6PPC & 6MM BEGGS. The BEGGS holds 2 grains less powder than the PPC, with equal velocity and energy, shooting the same weight bullet.
Edit: both cases using the same weight bullet.
Another example is the 6PPC & 6MM BEGGS. The BEGGS holds 2 grains less powder than the PPC, with equal velocity and energy, shooting the same weight bullet.
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OK, but are they both using the SAME powder, or NO???
IF NO, you can't call one case more "efficient" than the other.
The POWDER itself is what is allowing for the perceived "efficiency" of the case...
The case merely represents a volume of space where a given powder combusts in, generating the necessary energy to do work (generate velocity) upon a constant mass (same weight bullet).
Did you guys flunk Physics, or did you not even take the class?
Either way, there's no free lunch that allows for "X" case to cheat the laws of thermodynamics.
Nvreloader illustrated an accurate comparison, using constants to calculate 'efficiency' within a given case.
Unless someone can document a test that isolates the CASE ITSELF as the determining factor of "efficiency", while everything else remains a constant, the notion of one case being "more efficient" than another remains a subjective opinion.
But hey, if it makes ya feel better to shoot one, then keep on keepin' on about it, LOL
Same powder for the first example, and same for the second example.
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