Range Test: .45Cal Double PRB deer load

[roundball]

The question that can't be answered here is "how much less" for each?
My experiences / educated instincts tell me the combined energy transfer of both balls would still be significantly more than a single ball.
And at typical woods-shot-distances, a little reduction in MV shouldn't be a deal breaker at all...the differences (on game) would certainly show at 100-125yds for sure.

In my upcoming fall field test, if I get a normal woods shot at a deer and the D-PRB load doesnt do its job I'll be right here following up with the bad results.
But so far...my field test with the custom .40cal conical successfully delivered as predicted...the solid brass ball successfully delivered as predicted...and I'll be shocked if my D-PRB .45cal load is not successful.
And that's why I'm pursuing it...for the first hand experience either way it goes

 

[BrownBear]

I'm not sure the chronograph would change my mind because shooting for me would be inside 20 yards. If going from 2/3 oz of ball at 1500 fps to 1 1/3 oz of lead meant only going 1200-1300fps, I'd take it in a heartbeat. At 10 yards or less, I think that's a very good trade.

My hope would be to trade the small loss in velocity (surely it won't be cut in half) for double the surface area and ball weight with correspondingly more tissue damage.

All theoretical, but I'm basing my choice on a whole lot of bloody bullet holes with all sorts of calibers in almost 50 years of big game hunting.

 

[dbutch]

Have fun! :thumbsup:

 

[roundball]

I'm not sure the chronograph would change my mind because shooting for me would be inside 20 yards. If going from 2/3 oz of ball at 1500 fps to 1 1/3 oz of lead meant only going 1200-1300fps, I'd take it in a heartbeat. At 10 yards or less, I think that's a very good trade.

My hope would be to trade the small loss in velocity (surely it won't be cut in half) for double the surface area and ball weight with correspondingly more tissue damage.

Yes...and food for thought...comparing the double weight of 2 PRBs to an equivalent weight conical in T/C's Load Data charts should give a "rough" idea of the velocity of a pair of PRBs:

(One .45cal/128grn PRB: 80grns Goex=1929 fps/mv)
Rough equivalent of two:
.45cal/255grn Maxi-Hunter: 80grns Goex=1605 fps/mv

(One .58cal/279grn PRB: 100grns Goex=1428 fps/mv)
Rough equivalent of two:
.58cal/540grn Maxi-Hunter: 100grns Goex=1221 fps/mv

 

[rodwha]

For grins I ran those numbers through a ballistics calculator.

Increments are 25 yds and zero is 75 yds. BC is 0.62 and elevation set at 1000'.

1929/1058 758 (0.6") 551 (0.9") 409 (0.0") 323 (-2.4")

1605/732 523 (1.0") 392 (1.3") 313 (0.0") 265 (-3.3")

 

[roundball]

For grins I ran those numbers through a ballistics calculator.

Increments are 25 yds and zero is 75 yds. BC is 0.62 and elevation set at 1000'.

1929/1058 758 (0.6") 551 (0.9") 409 (0.0") 323 (-2.4")

1605/732 523 (1.0") 392 (1.3") 313 (0.0") 265 (-3.3")

Sorry, but I'm not sure what I'm seeing...for example, are you saying that the single PRB 1929 fps/mv is all the way down to 1058 fps at a mere 25yds ??

 

[rodwha]

Sorry.

The first number there (1929) is the velocity at the muzzle. The second number after the backslash (1058) is the energy in ft/lbs. The numbers after which are the energy figures at 25 yd intervals with the trajectory in inches within the parentheses.

The figures after is what each ball in your double load would likely have given the velocity figure you did for a conical. So each ball would be traveling about 1605 fps with 732 ft/lbs of energy at the muzzle, and each would have about 313 ft/lbs of energy left at 75 yds, which is what I zeroed them in at, but be -3.3" at 100 yds with only 265 ft/lbs left.

 

[George]

...BC is 0.62 ...

The BC of a .440" ball is 0.062, not 0.62. If that number was used in the calculation, and was not just a typo in the post, the numbers won't be correct.

I wouldn't know how to figure the ballistics of a double-ball load, what is the combined BC, what is the combined energy? The velocity and trajectory should be essentially the same as a conical of the same weight, but after that I'm lost.


Spence

 

[rodwha]

It was a typo. The decimal point was supposed to be before the 0. Ooops!

I'm not exactly certain how to figure up a double ball load, but I don't think anything is combined. I used the figures for a single ball at the velocity of both. There's just two of them so each has the same or similar figures, which are much lower than were only the one ball used.

I am no expert, and my sense of logic has failed me many times.

 

[rodwha]

The trajectory wouldn't be the same as with a conical of similar weight as it's BC value would be much higher.

 

[George]

At the short ranges you are dealing with the difference wouldn't be of practical concern.

Spence

 

[rodwha]

I'm not even sure of what I'm looking at.

It seems to me the single ball load is marginal at 100 yds for medium game. A single ball from the double load has similar figures at 75 yds. If a single ball is marginal how does two balls change the equation?

I can see this being beneficial for something dangerous in which you get once shot. You certainly would need to know how to adjust your POA.

It's interesting enough to want to try it myself a few times.

 

[Britsmoothy]

Rounding the two ball as they were a single projectile is folly. They are two and all be it down some will have a combined effect more than the single ball ever can!

Thats my take anyways!

B :thumbsup:

 

[bubba15301]

not legal in Pa either

 

[rodwha]

I didn't mean for the second set of info to taken as collective, but individual.

Each ball is moving much slower which seems to equate to less deformation and/or less penetration, but gives two wounds.

At the extreme I see where a single ball has enough to penetrate completely and expand some, but a dual ball load wouldn't completely pass through and may not deform, but gives two deep wounds that likely still go through the vitals.

I can see how this would make a good bear load back in the day.

 

[AWsaddles]

My experience with double ball is limited but I have killed one deer with it and my experience with it was one pass through and one moderately deformed ball on off side under the skin. I don't know how much the velocity or energy was changed with the load but one thing to consider was the ball passing through was still carrying some of its energy when it exited the deer while the one that did not pass expended all of its energy into the animal.
I plan on doing some shooting in a week or two and when I do I am going to chrono a few singles and doubles just to see velocity change.

 

[rodwha]

Did neither ball hit bone?

I can only guess that all of the mass in-between behaves similarly, but if not that may be why one passed through, and one did not.

But I can only assume each ball behaves similarly enough to call them equals.

 

[AWsaddles]

Yes I do know rib bones were hit but that is all I remember. It was a few years ago and don't recall which ball hit what.

 

[Joel/Calgary]

The question that can't be answered here is "how much less" for each?
My experiences / educated instincts tell me the combined energy transfer of both balls would still be significantly more than a single ball.
And at typical woods-shot-distances, a little reduction in MV shouldn't be a deal breaker at all...the differences (on game) would certainly show at 100-125yds for sure.

There have been multiple discussions of double balls, and this information has been posted more than once:

When done correctly/safely, you do actually gain more energy out of given powder charge with two balls. In the four single- vs. double-ball loads that Herb presented data for in this thread, the muzzle energy increases ranged from 17%-29%. He worked up a double-ball .40 hunting load so a friend could meet a minimum-projectile-weight regulation for deer, and it took the deer.

Also, I've seen a number of terminal-ballistics discussions that suggest that multiple impacts give disproportionate increases in stopping power, so two balls each hitting at 58-64% of the single-ball energy could easily be more effective than the single ball, assuming adequate penetration. Given that the higher the velocity, the faster the rate of slowing, I'd expect that the percentage of difference in energy would be increasing somewhat downrange compared to at the muzzle. Ain't a lot, but it is something to consider.

Regards,
Joel

 

[roundball]

Haven't seen any others, and I'm doing mine with a .45cal...but the references you mentioned shore up the concepts that my instincts were telling me, so that's good.
If I go enough times this fall, sooner or later I should get a deer in my sights and see how this double .45cal PRB load does first hand.