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What makes a cartridge efficient
- Thread starter calgarycanada
- Start date
Heck, ya coulda just had a hummer of a barrel on one, and/or a bummer of a barrel on the other?
Are we to assume they were both the same length barrel, too?
Same manufacturer?
Same twist rate?
It'd have to be different barrels, unless you were able to re-chamber the same barrel to the other cartridge?
If so, how could you keep barrel length a constant to fairly compare velocity???
How bout reamer design, same lead & throat dimensions for both cases???
Are we to assume they were both the same length barrel, too?
Same manufacturer?
Same twist rate?
It'd have to be different barrels, unless you were able to re-chamber the same barrel to the other cartridge?
If so, how could you keep barrel length a constant to fairly compare velocity???
How bout reamer design, same lead & throat dimensions for both cases???
Are you starting to see how foolish it would be to attribute "efficiency" to the CASE, alone???
Fredo, I very respectfully ask you to stop increasing your post count, create an argument and destroy this thread please.
Obviously some of us are on same page and you are not.
We are all here to learn and in my physics class they didn't teach about cartridge efficiency. Let's not argue and please don't post in this thread. Did I say please???
Again respectfully
Av
Some more Food for thought,
To add more info on/about cartridge ballistic efficiency,
I believe that powder type used and PSI values of the case design,
along with bbl lengths, Can and DO change Ballistic Efficiency of a case/load.
Here is the same case loaded to the MAX PSI values of the case design,
all the same spec's as before:
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, same bullet seating depth etc.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2283 fps= 3.57 grs of powder = 47.4% ballistic efficiency,
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2455 fps= 4.74 grs of powder = 42.8% ballistic efficiency,
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2627 fps= 6.01 grs of powder = 38.7% ballistic efficiency,
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 1850 fps= 1.77 grs of powder = 50.5% ballistic efficiency,
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2125 fps= 2.33 grs of powder = 50.6% ballistic efficiency,
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2373 fps= 2.99 grs of powder = 49.2% ballistic efficiency.
BARREL LENGTH changed to 11", no other changes made to load data,
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-11" bbl= 2047 fps= 3.57 grs of powder = 39.5% ballistic efficiency,
20 cal-29 gr bullet@ 43000 psi-11" bbl= 2216 fps= 4.74 grs of powder = 34.9% ballistic efficiency,
22 cal-29 gr bullet@ 43000 psi-11" bbl= 2357 fps= 6.01 grs of powder = 31.1% ballistic efficiency,
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-11" bbl= 1712 fps= 1.77 grs of powder = 43.2% ballistic efficiency,
20 cal-29 gr bullet@ 43000 psi-11" bbl= 1968 fps= 2.33 grs of powder = 43.4% ballistic efficiency,
22 cal-29 gr bullet@ 43000 psi-11" bbl= 2191 fps= 2.99 grs of powder = 41.9% ballistic efficiency.
As you can see the,
FPS and % of BE changed,
when everything else stayed the same.
Tia,
Don
To add more info on/about cartridge ballistic efficiency,
I believe that powder type used and PSI values of the case design,
along with bbl lengths, Can and DO change Ballistic Efficiency of a case/load.
Here is the same case loaded to the MAX PSI values of the case design,
all the same spec's as before:
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, same bullet seating depth etc.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2283 fps= 3.57 grs of powder = 47.4% ballistic efficiency,
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2455 fps= 4.74 grs of powder = 42.8% ballistic efficiency,
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2627 fps= 6.01 grs of powder = 38.7% ballistic efficiency,
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 1850 fps= 1.77 grs of powder = 50.5% ballistic efficiency,
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2125 fps= 2.33 grs of powder = 50.6% ballistic efficiency,
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2373 fps= 2.99 grs of powder = 49.2% ballistic efficiency.
BARREL LENGTH changed to 11", no other changes made to load data,
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-11" bbl= 2047 fps= 3.57 grs of powder = 39.5% ballistic efficiency,
20 cal-29 gr bullet@ 43000 psi-11" bbl= 2216 fps= 4.74 grs of powder = 34.9% ballistic efficiency,
22 cal-29 gr bullet@ 43000 psi-11" bbl= 2357 fps= 6.01 grs of powder = 31.1% ballistic efficiency,
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-11" bbl= 1712 fps= 1.77 grs of powder = 43.2% ballistic efficiency,
20 cal-29 gr bullet@ 43000 psi-11" bbl= 1968 fps= 2.33 grs of powder = 43.4% ballistic efficiency,
22 cal-29 gr bullet@ 43000 psi-11" bbl= 2191 fps= 2.99 grs of powder = 41.9% ballistic efficiency.
As you can see the,
FPS and % of BE changed,
when everything else stayed the same.
Tia,
Don
In your opinion,
What has the greatest effect on cartridge BALLISTIC Efficiency,
of the below provided examples?
As we all should know,
every case/load combo will change the effects of Ballistic Efficiency,
on what the end user wants to accomplish etc.
1. Bullet caliber,
2. Bullet weight,
3. Bbl length,
4. Powder type used,
5. Case capacity,
6. Combo of any of the above, which ones?
7. Some other aspect, not listed?
Why did you pick that aspect??
Here is the same case loaded to the same spec's:
Barrel length = 11"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-11" bbl= 1712 fps= 1.77 grs of powder = 43.2% ballistic efficiency,
20 cal-29 gr bullet@ 43000 psi-11" bbl= 1968 fps= 2.33 grs of powder = 43.4% ballistic efficiency,
22 cal-29 gr bullet@ 43000 psi-11" bbl= 2191 fps= 2.99 grs of powder = 41.9% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-11" bbl= 2047 fps= 3.57 grs of powder = 39.5% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-11" bbl= 2216 fps= 4.74 grs of powder = 34.9% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-11" bbl= 2357 fps= 6.01 grs of powder = 31.1% ballistic efficiency.
Barrel length = 22"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 1850 fps= 1.77 grs of powder = 50.5% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2125 fps= 2.33 grs of powder = 50.6% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2373 fps= 2.99 grs of powder = 49.2% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2283 fps= 3.57 grs of powder = 47.4% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2455 fps= 4.74 grs of powder = 42.8% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2627 fps= 6.01 grs of powder = 38.7% ballistic efficiency.
Barrel length = 33"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-33" bbl= 1919 fps= 1.77 grs of powder = 54.3% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-33" bbl= 2202 fps= 2.33 grs of powder = 54.3% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-33" bbl= 2462 fps= 2.99 grs of powder = 53.0% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-33" bbl= 2348 fps= 3.57 grs of powder = 54.3% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-33" bbl= 2574 fps= 4.74 grs of powder = 47.1% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-33" bbl= 2764 fps= 6.01 grs of powder = 42.8% ballistic efficiency.
Tia,
Don
What has the greatest effect on cartridge BALLISTIC Efficiency,
of the below provided examples?
As we all should know,
every case/load combo will change the effects of Ballistic Efficiency,
on what the end user wants to accomplish etc.
1. Bullet caliber,
2. Bullet weight,
3. Bbl length,
4. Powder type used,
5. Case capacity,
6. Combo of any of the above, which ones?
7. Some other aspect, not listed?
Why did you pick that aspect??
Here is the same case loaded to the same spec's:
Barrel length = 11"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-11" bbl= 1712 fps= 1.77 grs of powder = 43.2% ballistic efficiency,
20 cal-29 gr bullet@ 43000 psi-11" bbl= 1968 fps= 2.33 grs of powder = 43.4% ballistic efficiency,
22 cal-29 gr bullet@ 43000 psi-11" bbl= 2191 fps= 2.99 grs of powder = 41.9% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-11" bbl= 2047 fps= 3.57 grs of powder = 39.5% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-11" bbl= 2216 fps= 4.74 grs of powder = 34.9% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-11" bbl= 2357 fps= 6.01 grs of powder = 31.1% ballistic efficiency.
Barrel length = 22"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 1850 fps= 1.77 grs of powder = 50.5% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2125 fps= 2.33 grs of powder = 50.6% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2373 fps= 2.99 grs of powder = 49.2% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2283 fps= 3.57 grs of powder = 47.4% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2455 fps= 4.74 grs of powder = 42.8% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2627 fps= 6.01 grs of powder = 38.7% ballistic efficiency.
Barrel length = 33"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-33" bbl= 1919 fps= 1.77 grs of powder = 54.3% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-33" bbl= 2202 fps= 2.33 grs of powder = 54.3% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-33" bbl= 2462 fps= 2.99 grs of powder = 53.0% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-33" bbl= 2348 fps= 3.57 grs of powder = 54.3% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-33" bbl= 2574 fps= 4.74 grs of powder = 47.1% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-33" bbl= 2764 fps= 6.01 grs of powder = 42.8% ballistic efficiency.
Tia,
Don
Last edited:
CJ6
Silver $$ Contributor
This says it all IMHO. It's the SUM of total package that makes it efficient or not. edit to add, Type of use would be added also.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,
Don
Last edited:
In your opinion,
What has the greatest effect on cartridge BALLISTIC Efficiency,
of the below provided examples?
As we all should know,
every case/load combo will change the effects of Ballistic Efficiency,
on what the end user wants to accomplish etc.
1. Bullet caliber,
2. Bullet weight,
3. Bbl length,
4. Powder type used,
5. Case capacity,
6. Combo of any of the above, which ones?
7. Some other aspect, not listed?
Why did you pick that aspect??
Here is the same case loaded to the same spec's:
Barrel length = 11"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-11" bbl= 1712 fps= 1.77 grs of powder = 43.2% ballistic efficiency,
20 cal-29 gr bullet@ 43000 psi-11" bbl= 1968 fps= 2.33 grs of powder = 43.4% ballistic efficiency,
22 cal-29 gr bullet@ 43000 psi-11" bbl= 2191 fps= 2.99 grs of powder = 41.9% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-11" bbl= 2047 fps= 3.57 grs of powder = 39.5% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-11" bbl= 2216 fps= 4.74 grs of powder = 34.9% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-11" bbl= 2357 fps= 6.01 grs of powder = 31.1% ballistic efficiency.
Barrel length = 22"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 1850 fps= 1.77 grs of powder = 50.5% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2125 fps= 2.33 grs of powder = 50.6% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2373 fps= 2.99 grs of powder = 49.2% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2283 fps= 3.57 grs of powder = 47.4% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2455 fps= 4.74 grs of powder = 42.8% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2627 fps= 6.01 grs of powder = 38.7% ballistic efficiency.
Barrel length = 33"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-33" bbl= 1919 fps= 1.77 grs of powder = 54.3% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-33" bbl= 2202 fps= 2.33 grs of powder = 54.3% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-33" bbl= 2462 fps= 2.99 grs of powder = 53.0% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-33" bbl= 2348 fps= 3.57 grs of powder = 54.3% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-33" bbl= 2574 fps= 4.74 grs of powder = 47.1% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-33" bbl= 2764 fps= 6.01 grs of powder = 42.8% ballistic efficiency.
Tia,
Don
Obviously I'm not being able to communicate properly. I'll add this and it may help others understand as well.
Now run same bullet as above in a case that has twice the volume then your case above. If not available in real world, let's assume we can design a new case for this study. Assume body taper, shoulder angle etc stay the same.
Use any powder suitable for that case volume.
Let's keep anything/everything else the same.
Run the numbers again, bring pressure upto 43000 psi.
Forget about ballistic efficiency percentage for now.
Does velocity of same bullet doubles? Or even come close to double?
Different powders can have different energy output so atleast we should be able to bring velocity upto 180% or so, right?
If yes, I'm just more stupid then I like to admit and thread ends here.
If not, why not? And that my friends is the whole question.
To double the velocity of a given bullet we have to pick a case with lot more then double the volume of original case? Don't we?
To everyone, please don't be offended, I'm not arguing, I'm seriously asking.
Av
Here is the spec's for double and triple the case capacity,
using the same spec's/info as the above data spec's,
I have added the % of BE as the results are there when doing the test.
I am not offended, I like to learn and better understand also.
Barrel length = 22"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 1850 fps= 1.77 grs of powder = 50.5% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2125 fps= 2.33 grs of powder = 50.6% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2373 fps= 2.99 grs of powder = 49.2% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2283 fps= 3.57 grs of powder = 47.4% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2455 fps= 4.74 grs of powder = 42.8% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2627 fps= 6.01 grs of powder = 38.7% ballistic efficiency.
----------------------------------------------------------------------------------------------------
Double case capacity info
Barrel length = 22"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2244 fps= 3.06 grs of powder = 43.0% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2506 fps= 3.81 grs of powder = 44.6% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2650 fps= 3.98 grs of powder = 46.1% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2506 fps= 5.58 grs of powder = 41.6% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2967 fps= 7.43 grs of powder = 41.3% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 3112 fps= 8.09 grs of powder = 40.3% ballistic efficiency.
Triple case capacity info
Barrel length = 22"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2943 fps= 5.42 grs of powder = 41.7% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2770 fps= 4.93 grs of powder = 40.7% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2943 fps= 5.42 grs of powder = 41.7% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 3425 fps= 10.53 grs of powder = 37.3% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 3207 fps= 9.16 grs of powder = 37.8% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 3425 fps= 10.53 grs of powder = 37.5% ballistic efficiency.
Tia,
Don
Here is the spec's for double and triple the case capacity,
using the same spec's/info as the above data spec's,
I have added the % of BE as the results are there when doing the test.
I am not offended, I like to learn and better understand also.
Barrel length = 22"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 1850 fps= 1.77 grs of powder = 50.5% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2125 fps= 2.33 grs of powder = 50.6% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2373 fps= 2.99 grs of powder = 49.2% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2283 fps= 3.57 grs of powder = 47.4% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2455 fps= 4.74 grs of powder = 42.8% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2627 fps= 6.01 grs of powder = 38.7% ballistic efficiency.
----------------------------------------------------------------------------------------------------
Double case capacity info
Barrel length = 22"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2244 fps= 3.06 grs of powder = 43.0% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2506 fps= 3.81 grs of powder = 44.6% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2650 fps= 3.98 grs of powder = 46.1% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2506 fps= 5.58 grs of powder = 41.6% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2967 fps= 7.43 grs of powder = 41.3% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 3112 fps= 8.09 grs of powder = 40.3% ballistic efficiency.
Triple case capacity info
Barrel length = 22"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2943 fps= 5.42 grs of powder = 41.7% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2770 fps= 4.93 grs of powder = 40.7% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2943 fps= 5.42 grs of powder = 41.7% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 3425 fps= 10.53 grs of powder = 37.3% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 3207 fps= 9.16 grs of powder = 37.8% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 3425 fps= 10.53 grs of powder = 37.5% ballistic efficiency.
Tia,
Don
Av
I am doing a 243 -vs- 6mm (standard cases) with 6 different powders using the 105 gr bullet.
Will post info in the am.
Tia,
Don
I am doing a 243 -vs- 6mm (standard cases) with 6 different powders using the 105 gr bullet.
Will post info in the am.
Tia,
Don
Av
Here is the spec's for double and triple the case capacity,
using the same spec's/info as the above data spec's,
I have added the % of BE as the results are there when doing the test.
I am not offended, I like to learn and better understand also.
Barrel length = 22"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 1850 fps= 1.77 grs of powder = 50.5% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2125 fps= 2.33 grs of powder = 50.6% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2373 fps= 2.99 grs of powder = 49.2% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2283 fps= 3.57 grs of powder = 47.4% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2455 fps= 4.74 grs of powder = 42.8% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2627 fps= 6.01 grs of powder = 38.7% ballistic efficiency.
----------------------------------------------------------------------------------------------------
Double case capacity info
Barrel length = 22"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2244 fps= 3.06 grs of powder = 43.0% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2506 fps= 3.81 grs of powder = 44.6% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2650 fps= 3.98 grs of powder = 46.1% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2506 fps= 5.58 grs of powder = 41.6% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2967 fps= 7.43 grs of powder = 41.3% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 3112 fps= 8.09 grs of powder = 40.3% ballistic efficiency.
Triple case capacity info
Barrel length = 22"
Bullseye powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 2943 fps= 5.42 grs of powder = 41.7% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 2770 fps= 4.93 grs of powder = 40.7% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 2943 fps= 5.42 grs of powder = 41.7% ballistic efficiency.
Norma 123 powder results,
17 cal-29 gr bullet@ 43000 psi-22" bbl= 3425 fps= 10.53 grs of powder = 37.3% ballistic efficiency.
20 cal-29 gr bullet@ 43000 psi-22" bbl= 3207 fps= 9.16 grs of powder = 37.8% ballistic efficiency.
22 cal-29 gr bullet@ 43000 psi-22" bbl= 3425 fps= 10.53 grs of powder = 37.5% ballistic efficiency.
Tia,
Don
There we go, so doubling the capacity doesn't double the output. Even tripling the capacity doesn't give us double the velocity.
"So there is a point of diminishing return. Some small cases can push same bullet almost as fast as same caliber bigger cases."
That's what I have been asking since start of this thread, why is that?
Av
There are several reasons, "Why is that",
Some of them are,
The TYPE of propellants we use,
The type of cartridge case MATERIAL we use,
brass/primer pockets only works well to about 65,000 psi,
then things start to get on the ragged edge,
and weapons/loads can go "BOOM" in a heart beat.
The design and strengths of weapons we use,
plus others items,
BUT, work very well to a certain point.
I am speaking in general terms,
To give you some info and answer to you question,
here is what would be needed to DOUBLE the speed of the first case example,
17 cal-29 gr bullet @ 43000 psi-22" bbl= 1850 fps= 1.77 grs of Bullseye powder = 50.5% ballistic efficiency.
17 cal-29 gr bullet @ 172912 PSI- 22" bbl = 3700 fps = 8.85 grs of Bullseye powder = 40.4% BE.
As you can see, the case is the first limiting factor,
the second is the strength of the weapon, plus other factors.
Tia,
Don
There are several reasons, "Why is that",
Some of them are,
The TYPE of propellants we use,
The type of cartridge case MATERIAL we use,
brass/primer pockets only works well to about 65,000 psi,
then things start to get on the ragged edge,
and weapons/loads can go "BOOM" in a heart beat.
The design and strengths of weapons we use,
plus others items,
BUT, work very well to a certain point.
I am speaking in general terms,
To give you some info and answer to you question,
here is what would be needed to DOUBLE the speed of the first case example,
17 cal-29 gr bullet @ 43000 psi-22" bbl= 1850 fps= 1.77 grs of Bullseye powder = 50.5% ballistic efficiency.
17 cal-29 gr bullet @ 172912 PSI- 22" bbl = 3700 fps = 8.85 grs of Bullseye powder = 40.4% BE.
As you can see, the case is the first limiting factor,
the second is the strength of the weapon, plus other factors.
Tia,
Don
There we go, so doubling the capacity doesn't double the output. Even tripling the capacity doesn't give us double the velocity.
"So there is a point of diminishing return. Some small cases can push same bullet almost as fast as same caliber bigger cases."
That's what I have been asking since start of this thread, why is that?
To accelerate the bullet, there has to be gas pressure at the bullet base. So you need not only accelerate the bullet, but also the mass of propellant gases behind it to the same speed (and more). In high power cartridges, more and more of the propellant is eaten up for accelerating the propellant gases, not the bullet.
In the old 105 mm M68 tank cannon, pressure at the projectile base was typically 30 percent less than measured in the chamber. With high power rifle cartridges you have a similar effect.
This is the main reason for the observation of diminishing effect.
In the old 105 mm M68 tank cannon, pressure at the projectile base was typically 30 percent less than measured in the chamber. With high power rifle cartridges you have a similar effect.
This is the main reason for the observation of diminishing effect.
To accelerate the bullet, there has to be gas pressure at the bullet base. So you need not only accelerate the bullet, but also the mass of propellant gases behind it to the same speed (and more). In high power cartridges, more and more of the propellant is eaten up for accelerating the propellant gases, not the bullet.
In the old 105 mm M68 tank cannon, pressure at the projectile base was typically 30 percent less than measured in the chamber. With high power rifle cartridges you have a similar effect.
This is the main reason for the observation of diminishing effect.
Now this makes sense. Thanks
The larger the caliber and case, and heavier the bullet weight,
the less efficient the load is.
I believe, that any load that is over 25-30% in BE, is a very good load,
per Dr. K Howell, IIRR.
Tia,
Don
the less efficient the load is.
I believe, that any load that is over 25-30% in BE, is a very good load,
per Dr. K Howell, IIRR.
Tia,
Don
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