Approx Muzzle Velocity-Bullet Weight Graph

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Underclocked

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This old graph was made by Walt (Twanger). This is calibrated for a White 97 using Triple 7 FFg but can be used to approximate your muzzle velocity from most any (non-smokeless) m/l rifle for a given load volume and bullet weight. Figure if the powder is hotter, add a bit and if the powder isn't as hot as T7 FFg subtract a bit. It should get you in a close ballpark of what your rifle/load will actually produce.

Divide your VOLUMETRIC powder charge (in grains) by the actual weight (in grains) of the projectile, find that spot on the horizontal axis and go straight up to the blue curve. Where it intersects that curve, read the velocity directly to the left on the vertical axis.

ie2w41.jpg


As you can see, there is also a line calibrated for the White Javelina and T7 FFFg. That should yield results very close for the CVA/Traditions/Knight or any other long barrel single shot BP pistol.

SabotLoader and/or Cayugad, you guys might want to save this somewhere in case I lose it on my host. Fairly useful graph.
 
Mods:

Is the image from this post salvageable? It doesn't display. (Here or over at thedwbs)

Thanks!
 
JStanley said:
Mods:

Is the image from this post salvageable? It doesn't display. (Here or over at thedwbs)

Thanks!

I believe UC has deleted it from his picture storage site - so it is lost to the forum..
 
Ok, thanks SL.

UC - any chance you could repost that graph? Until I get around to buying a chronograph, that graph was extremely useful! I promise, I'll save the image somewhere for safe keeping :wink:
 
I didn't delete it. My internet provider decided to do away with all personal storage without even notifying me. Sorry for the troubles but I had nothing to do with it, dayum 'em!

I've been trying to fill in the gaps as I locate them but haven't had much luck doing so. Luckily, I have a backup of the image and have just uploaded it elsewhere. This upload may not last long or it may be there indefinitely, can't rely on the host. So please, a few of you should save a copy of this picture in case it is needed again.

ie2w41.jpg
 
I know these are appromimates but can anyone actually confirm their values using a chronograph placed 10 feet from end of muzzle, especially for a CVA ACURRA v2 using 110 gr BH209 with a 300 gr power belt.
thanks
MARTIN LOADER
 
:yeah:

Go to Blackhorn209 .com....... click on DATA LOAD then muzzleloaders............ It may answer your question.

Ray.............. :yeah:
 
hawgslayer said:
:yeah:

Go to Blackhorn209 .com....... click on DATA LOAD then muzzleloaders............ It may answer your question.

Ray.............. :yeah:

Questions I have about the load data provided by WP Blackhorn209
Does anyone know if those velocities were shot from the same gun in the same conditions?
What length bbl was used for testing?
Do those that have a chronograph find them inflated or within reason?

I see some velocities on there that when compared to the others of similar weight bullets, leave me scratching my head.
 
Give an example along with your calculation using the info above along with your reference and let's figure out the discrepancy. This chart was created before BH209 came into existence, so it may throw a monkey wrench into the approximations. I believe Walt's White 97 was a standard model with a 22" barrel.

Using the chart, 100 grains by volume of Triple7 FFg with a 300 grain bullet (decimal fraction of .333) should yield a velocity of about 1750 fps from a similarly barreled rifle. I would expect BH209 to be 10-15% more energetic than the T7 FFg so the so I would just guestimate a value of 115 grains equivalent, yielding a decimal fraction of ~.383 and rough velocity of 1820 or so fps. Since we did not specify exactly WHICH bullet we were shooting, I think that figure jives pretty well with the BH209 provided data. (I see 1892, 1850, 1855, 1813, 1925, 1857, 1816, 1791, 1815, and 1826fps for 300 grain bullets with 100 grains volumetric of BH209). I'm guessing their data was generated using at least a 26" barrel but the approximation is still in the ballpark for almost all those bullets.
 
I think with BH209 that curve steepens as bullet weight increases due to how it responds to pressure. With a 200gr. bullet it struggles to outperform 777 but with a 300gr bullet velocities are now about 10% faster. Even on the BH website you see a marginal drop off in velocity as bullet weight increases. This really bodes well for the notion of throwing a heavier pill to get more punch.
 
I chronographed my thompson triumph shooting 250 grain barnes mz expanders with original sabot. driven by 80 grains of blackhorn 209. The speed at five feet from muzzle was 2125 feet per second.
 
My Wolf with a .430 305 grain projectile, MMP green sabot, 100 grains of loose T7, and a Winchester 209 registered just over 1800 on my chrony. Your spot on. I didn't include the weight of the sabot though.
 
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