Black Powder Shotgun Power Factor, by SWAG

[Amarillo Rattler]

The following is unscientific and of unknown reliability.

 

I have noticed that shotgun knock downs have  always gone down during matches and practice sessions when hit with any of my black powder loads that varied from 3/4 oz to 1 1/8 oz.

 

I thought, first mistake, that a Power Factor calculation might be helpful for ammo selection during matches, but did not find any references for determining an accurate Power Factor for shotguns.

 

My method included:

Browning BSS with 22 1/2' barrels;

Muzzle velocity measured with the chronograph first screen 2 feet in front of muzzle;

Pattern the load on 36" square paper with a 9" paper plate glued to the center, shot at 12 yds; 

Calculate the muzzle Power Factor;

Reduce the muzzle Power Factor by 9% (NRA stats) for Power Factor at the target distance of 12 yds;

Reduce the 12 yd Power Factor by percentage of shot pellets on target to arrive at Target Power Factor.

 

As a control, I used my trap/skeet 1oz load with Red Dot powder, the load data was for 1,200 fps. When chornographed it measured 1177 fps. Close enough to proceed with patterning. That was 58% on the 9" paper plate at 12 yds and Power Factor of 272. 

 

The Black Powder loads included 1 1/8 oz, 1 oz, 7/8 oz and 3/4 oz, the last being my practice load. The one shot power factor for each of those loads was:

1 1/8 oz =  176 PF

1 oz = 143 PF

7/8 oz =  157 PF

3/4 oz = 105 PF

 

The 7/8 oz load had a higher PF than the 1 oz load due to a higher percent of pellets on the plate.

 

The SWAG variables include:

Statistically insignificant since only 1 round was used of the several fired (used the higher number of the left or right barrel);

The shot was reclaimed and included a mix of 9, 8 and 7.5;

The smokeless chronograph velocities were within 10 fps for both barrels, but the BP velocities had wide variances.

The shot velocity at 12 yds is a best guess from NRA ballistics tables.

The 3/4 oz load was 1.5F powder, all others were 2F powder.

 

In practice yesterday, the 3/4 oz load knocked. the heck  out of our practice steel, a 9" plate suspended from the top ( no down range resets).

 

I will gladly share the load data to any Pard interested, send a PM. 

By the way, Winchester Low Noise/Low Velocity 12 ga loads probably  have a higher PF than my 1 1/8 BP loads. 

 

Just sayin'

Amarillo Rattler

[John Henry Quick]

I'm not sure I understand why we care about PF in BP shotshell loads.  I use a 2-1/2 dram load (leaving out other components to stay off Allie's hit list) that knocks them flat every time (assuming I do my part) and they make an awesome sound.  Smokeless shooters always OO and AH and ask me if I'm shooting a cannon and they're astounded when I remind them that 2-1/2 drams is on the low end of the BP shotshell scale.  

[Cliff Hanger #3720LR]

For shotguns, PF is not as relevant as shot density on the targets. (pellet count on the target used)

To get true PF you would need the velocity and the pellet count converted to weight on target.

But this is not going to give you a true PF because there is no way to have all the pellets hit the target at the same time, transferring the energy to the plate.

 

Example: A 7/8 ounce load can have a higher energy transfer than a 1.5 ounce load if the shot density is greater with the 7/8" ounce load than the 1.5 ounce load.

 

Light shotgun load are usually more than 800'/sec. More in the 900'/sec to 1150'/sec range.

 

To improve your shotgun knockdown performance, work on getting a tighter pattern on the target with a higher pellet count.

 

Also, placement on the target will effect the knockdown.

Hitting center of target, provided the hinge is directly under or over hinge will improve knockdown performance.

Hitting near an edge may knockdown the target but the required energy will be more to over come the twisting of the target that puts a binding force on the hinge.

 

Suggestion is to pattern shoot your guns (shoot at the same spot) at the distance you normally shoot knockdown targets and find the center of pellet impact.

Not necessarily center of point of aim and certainly not where the wad hits)

Adjust your aiming point to bring center of pellet density impact to center of target mass/center on hinge point.

============

The above experiments is an interesting one to preform and produces some data that causes more questions and more experimenting.

The pellet impact time variant changes from shot to shot and wrecks havoc on trying to get good PF numbers.

I went back to pattern density which was much easier to see and correct for.

 

Nice job Armadillo Rattler.

 

[Amarillo Rattler]

"Nice job Armadillo Rattler"

 

I saw that!

 

The omitted data included fiber wads, which averaged -08% density on target. Much better on closer (less than 12 yd) KD targets.

Amarillo Rattler

[Doc Shapiro]

When I started loading BP shotshells with 2F, I had trouble with knockdowns.  My load included a pretty thick fiber wad to take up the extra space.  Shot on top of the wad with a card on top of the shot.  When I patterned it, I found that the fiber wad was blowing a hole through the center of the pattern.  I switched to Winchester Red plastic wad and that fixed the problem.

 

While this is a pretty big tangent, it may be of help to someone.

[Cliff Hanger #3720LR]

I understand shooters that shoot BP want to use the original loading materials. Fiber wads and cards.

But it you think about it, in the 1800s, the shotgun was not a defensive gun unless it was the only gun you had.

It was a meat on the table gun and wider pattern help accomplish that.

 

Today's shooters are shooting more targets than game and they want their patterns to stay together and reach farther.

We who shoot cowboy action want our patterns to be even tighter so we slow the loads down to help prevent plastic wads from opening up and having the shot spread as fast as it would normally.

Yes, we want less recoil as well.

 

As Doc Shapiro has pointed out, the modern plastic shot wad keeps the shot contained longer after leaving the barrel keeping the shot pattern tighter.

 

If you want to keep things original comes with drawbacks of loose patterns and if you want to be more competitive, you may have to compromise and use the tools needed to get you there.

 

One of those tools will be the plastic shot cup or plastic wad.

 

 

 

[John Boy]

Quote

If you want to keep things original comes with drawbacks of loose patterns and if you want to be more competitive, you may have to compromise and use the tools needed to get you there.

 

Tell this to the British shotgun makers and manufacturers of BP paper shotshells with wads and they will tell you ... 'Your smoking dope'

Loose patterns with wads can only be effected by the bore choke of the gun - and cut the barrel down to remove the chock taper, one is asking for open patterns

[John Boy]

Quote

The following is unscientific and of unknown reliability.

Amarillo - should SASS form  a Committee to determine - evaluate and establish baselines for the treatise you posted?

 

[Cliff Hanger #3720LR]

Why ask the British?

I do not see British guns or ammunition at cas matches in the USA.

;^)

 

[John Boy]

Quote

I do not see British guns or ammunition at cas matches in the USA.

I have, including my 1901 Neuman Bros, external cock 12 ga  ...  Barrels made by the Brits - assembled in Belgium and sold in the US

And least we forget, the British did in the BP era and still do make many excellent SxS's

[Cliff Hanger #3720LR]

John Boy,

I certainly agree with you on the British making some quality sxs.

 

[Amarillo Rattler]

5 hours ago, John Boy said:

Amarillo - should SASS form  a Committee to determine - evaluate and establish baselines for the treatise you posted?

 

Lawdy NO!

 

In the OP, I opined the following was unscientific and of unknown reliability.

In the topic caption, I stated it was SWAG.

SWAG is a more advanced form of WAG.

 

But, if a SASS Committee can be formed, see if they need a consultant (hired of course).

 

On the serious side, I wanted to find out how my SG loads, from 3/4 oz to 1 1/8 oz, compared to the 105/158 gr 38 Special and 165/200 gr 44-40 loads on KD targets. From what I can see while shooting stages, the various SG loads hit the KDs as hard as the center fire rounds.

 

I'll do the 12 yd chrono work on the 38 and 44-40 loads at 12 yds and post a follow up.

 

Amarillo Rattler

[Zeke Zelazko]

Got to weigh in here. Only been doing CAS for two years, but shooting BP shotguns for 4 decades.

 

Couple of thoughts here as I've spent considerable time patterning my sxs's for both hunting, CAS and home defense.  My CAS load is slightly oversquare (more shot volume than powder) at a little over 1oz of shot. For me it's more about getting the components in the size cases I'm using. Moderate amounts of powder with moderate amounts of shot seem to knock things down.

 

I use a "base-cut off" plastic wad over a 1cm fiber wad over an over-powder card.  The goal here is to cushion the shot from extra heat and pressure of BP and reduce the amount of plastic in the barrel.

 

Regarding the plastic wad - it shrinks my pattern with Rossi Overland IC & M close to 50% with either barrel. I omit that component for home defense because I don't want all that shot going into 6" at 7 yards, but that is fine for CAS. Without the plastic cup, it spreads to 10"-11".  I go back to the plastic cup for hunting loads.

 

Regarding the fiber wad (sorry - have to go physics teacher here). The fiber wad adds mass to you pattern, but is not part of your shot load. My fiber wads all hit about the center of target. A  12 gauge, 1 cm thick fiber wad has a mass of 20 grains - that's equivalent to 20 individual #8.5 shot that I'm loading right now - equivalent to 20 pieces of shot hitting in less than a square inch.  The net gain in energy on target by the fiber wad is greater than the several pieces of shot it may displace in the pattern. Knocking a target down is all about energy transfer to target.  The above would be different if we weren't hitting solid, stationary targets at about a 90 degree angle or if you were trying to kill something and need the penetration.

 

Shoot sharp!

[Father Kit Cool Gun Garth]

All this talk about BP loads makes me .

What I do know is that somehow Amarillo can see the targets through all that smoke.

 

          

[Chantry]

17 hours ago, Cliff Hanger #3720LR said:

Why ask the British?

I do not see British guns or ammunition at cas matches in the USA.

;^)

 

 I've used 3 British hammer guns and a French Darne clone at both local and state level matches and will continue to do so.

[Fairshake]

I've always been a BP shooter since joining SASS and started shooting BP in the early 70's while employed in a gun store. 

I first tried loading several trial loads for my SXS using the original fiber wads and card over wads. My first time at shooting the KD's was a very humble experience as I was failing to knock down the targets with 1 1/8 loads and full charges of BP. What at discovered with a session on paper was the exact same thing as was posted by Doc Sharpio, all the pattern's had a huge hole in the center with the fiber wad going dead center. The wad itself was not strong enough to knock down the steel, of course and I knew that my loads needed some fast change. I tried several plastic wads and none of them allowed me to add the amount of BP that I needed to give my loads the KaBoom I was looking for. I finally came across the perfect wad, a short green wad made in Italy. I also used a blend of BP that upped the charges. All of this is put into Remington green or gold hulls. Since I started using this load, I've never failed to miss a KD or clay bird. 

I've had other shooters use this load with the same results, so it's been tested and proven. I've had some bad medical issues that stopped me from being a active shooter and I'm trying very hard to get back to shooting SASS matches again. Take Care Fairshake   

[John Henry Quick]

11 minutes ago, Fairshake said:

I've always been a BP shooter since joining SASS and started shooting BP in the early 70's while employed in a gun store. 

I first tried loading several trial loads for my SXS using the original fiber wads and card over wads. My first time at shooting the KD's was a very humble experience as I was failing to knock down the targets with 1 1/8 loads and full charges of BP. What at discovered with a session on paper was the exact same thing as was posted by Doc Sharpio, all the pattern's had a huge hole in the center with the fiber wad going dead center. The wad itself was not strong enough to knock down the steel, of course and I knew that my loads needed some fast change. I tried several plastic wads and none of them allowed me to add the amount of BP that I needed to give my loads the KaBoom I was looking for. I finally came across the perfect wad, a short green wad made in Italy. I also used a blend of BP that upped the charges. All of this is put into Remington green or gold hulls. Since I started using this load, I've never failed to miss a KD or clay bird. 

I've had other shooters use this load with the same results, so it's been tested and proven. I've had some bad medical issues that stopped me from being a active shooter and I'm trying very hard to get back to shooting SASS matches again. Take Care Fairshake   

 

Exactly what green Italian wad was this?

 

[Rio Brazos Kid]

  For Black Powder loads in SASS, you will be hard pressed to find a better performing wad for your 12 ga. loads than the old, now discontinued, WAA12R Winchester wad.  No to worry though as Claybuster makes a clone of that wad, the CB1138-12 wad.  Makes shotshell KD loads perform very well, and gives the loads the necessary internal volume inherently needed for Black Powder loads

 

     RBK

[Trooper Ozzy]

4 minutes ago, Rio Brazos Kid said:

  For Black Powder loads in SASS, you will be hard pressed to find a better performing wad for your 12 ga. loads than the old, now discontinued, WAA12R Winchester wad.  No to worry though as Claybuster makes a clone of that wad, the CB1138-12 wad.  Makes shotshell KD loads perform very well, and gives the loads the necessary internal volume inherently needed for Black Powder loads

 

     RBK

Rem gun club hulls, largest Lee Dipper 4.3 powder, red wad, 1 1/8 shot,  crimps perfect in a cheap Lee Load All.

[Colorado Coffinmaker]

Simple scientific formula:

 

Does your BP Load take down the Poppers??    Yes.  Leave the load alone, don't over think it.

                                                                                    NO.  Change the load, don't over think it

[Trooper Ozzy]

Simpler formula......

Can the spotters see the poppers after 2 quick shots?  Yes, add more powder.  Grits are for breakfast, never in reloads.

Note the short wad allows the correct/adequate amount of powder.  Spacing is just about perfect with 1 1/8 oz shot. 

[Sedalia Dave]

You all use way too much shot. I have excellent results with 7/8 oz loads. Still plenty of boom.

[Rooster Ron Wayne]

8 hours ago, Sedalia Dave said:

You all use way too much shot. I have excellent results with 7/8 oz loads. Still plenty of boom.

My Words Exactly .

Been using 7/8 oz BP loads for years.

Loadded on a Lee Load all with the Gray Plastic Wad .

Works great and Low Recoil.

Rooster 

[Trooper Ozzy]

...don't want to just wound it.

 

[John Henry Quick]

11 minutes ago, Trooper Ozzy said:

...don't want to just wound it.

 

 

True dat.  I used to make mouse-fart BP shotshell loads, but then I realized that I'm not out there to compete with the mouse-fart crowd.  I have one load for everything and 1-1/8 over 2-1/2 drams is not uncomfortable to shoot.  I've never patterned it (I know I should), but I shoot at least as well with them as I do with factory AA's.  I think maybe some people are just going a little too gonzo with the powder load.

 

[Fairshake]

I must apologize to y'all for omitting the info on the wad I use. While writing my posting I drew a complete blank and could not remember the name of a wad that I've used for 5 years. I had to laugh at myself.

All of my loading equipment, supplies, manuals, info sheets  have been in storage for over a year as my wife and I were victims of the Great Louisiana Flood of August 2012. We had to leave our home for over 6 months and still have not been able to move those things and other furniture back into our home.  

I was finally able to find the info online after my mind was able to steer me in the correct direction. The wads are made by Gualandi and the number is 072SSW, they are green in color and sold by Ballastic Products. I found them at Precision Loading although they were white in color but had the same specs.

A lot of shooters don't understand that it takes a larger load of BP to achieve the same results as those that load that new fad powder, I can't recall it's name at this moment. 

I noticed where some of the postings stated that  some of us was using too much powder to achieve our kaboom. My feelings on that is that when I became a member of SASS, I had no intentions of ever trying to out do the next man. I load all of my shells as full as I can get them, my 44wcf loads are to the top with the bullet pressing it down when seated. I always leave the range with a huge smile even though I finished down the list. I feel I'm doing it the 1870's way. Take Care Fairshake