Homemade BP Chrono Data

[Eagle66]

This is a follow up to my “Thoughts on Homemade BP” thread.

For the test, I used Goex fffg and my (black willow charcoal) powder processed & screened fffg, as described in the thread. I prepared 3 charges of each by weighing out 70.0 gr on my beam-type powder scale. I used a powder dribbler to make sure the charges were identical. Each charge went into a separate labeled vial. To make sure all the powder went into the barrel, I poured through a powder funnel in the muzzle.

The rifle was a Cabelas Traditional Flintlock Hawken Rifle in .54 cal. Pan prime was my own fffg, same batch. The balls were .530, 221gr (± 1 gr) all from the same casting run, patched with .010 ticking greased with Crisco. After each shot, the bore was swabbed with a wet patch followed by 3 dry patches.

The test was shot over a ProChrom CEI-3800 digital chrono. There was no significant wind that day. And now, the important part:

My powder

1113 fps
1142 fps
1154 fps

Goex

1313 fps
1336 fps
1342 fps

[Ajax]

looks good but what was the volumetric of the weighed powder?


Andy

[Texantothecore]

Those are good numbers with low extreme spreads. Nice job with good data.

Congratulations.

[curator]

Ajax has a point. Volumetric comparison might be better since this is the way black powder is usually measured for loading. In the 19th century new powder supplies were subjected to testing and loads were modified according to the new powder's strength using an eprovette.

105343

[Eagle66]

looks good but what was the volumetric of the weighed powder?


Andy

Sorry about that,Andy. I hadn't thought about volume. I just went down to my bench and checked. 70 gr of mine or Goex is ~6.2cc, or 1-1/4 teaspoon. At the range, I'd use one like these:

http://www.trackofthewolf.com/Categories/PartDetail.aspx/86/2/MEASURE-SET

or, on my powder horn, like these:

http://www.trackofthewolf.com/Categories/PartDetail.aspx/81/3/SPOUTS

cut down a bit to the weight I wanted.

Mark

[Ajax]

So if what i found is right 1-1/4 teaspoon is 100 grain volumetric. 6.2cc is 93 grains. Thats a pretty big spread between the 2.

Andy

[missionary5155]

Good morning Eagle66
Nice right up and a good comparison of the two. Your powder looks consistant and that is what matters. You have a product to be proud of and will be of good use.
Having worked with 3F last time up in my two Hall Rifles, the 50-95, 32WCF, 44WCF and a couple others I will have to ask... is it possible your samples of 3F Goex should also have been screened ?
I noted as I was working through my can of 3F Goex that there was a good amount (call it 5%) of very fine powder (4F looks) mixed in. This I seperated to use in flash pans. Possibly there is a greater velocity difference in the Goex 3F and your good powder due to the mix of thes fine granuals in the Goex loads thus producing a higher FPS. It does not affect your powder's good result... just that maybe it would show a slower FPS reading with the Goex if it was also screened.

I am encourged to try my hand at BP production. As much as I like shooting the 50-95 with 3F that would sure make shooting it far more economical. Thanks again for the fine report. You did good !
Mike in Peru

[missionary5155]

Silly thing double posted !!

[Lead Fred]

Goex in my flinter gets me 1650fps with 55gr and 2033fps from a full charge of 75gr.

Never thought to try crico, always used TC 1000+

[missionary5155]

Howdy Lead Fred
Crisco you can rub it in or (easier) melt a dood amount and drop patches in. I usually squezed out the excess. Set aside on wax paper and let dry.
You can do the same with a 50-50 mix of olive oil and Beeswax. Melt together then dip the patches. If you need it more liquid add a bit more olive oil.

Mike in Peru

[Fly]

Your powder should be faster the Goex.What charcoal are you using?

Fly

[Eagle66]

Fred, Those are some great numbers. What was the caliber & ball weight?

Fly, I've been using Black Willow charcoal.


... is it possible your samples of 3F Goex should also have been screened ?
I noted as I was working through my can of 3F Goex that there was a good amount (call it 5%) of very fine powder (4F looks) mixed in. This I seperated to use in flash pans. Possibly there is a greater velocity difference in the Goex 3F and your good powder due to the mix of thes fine granuals in the Goex loads thus producing a higher FPS. It does not affect your powder's good result... just that maybe it would show a slower FPS reading with the Goex if it was also screened.


Missionary, I think you're on to something! I just screened 100gm of my Goex fffg thru 40, 70, & 100 screens. There was 81 gm of -40+70(fffg). 19 gm of -70+100(ffffg). There was only a pinch of +40 and a pinch of -100

I'm going make up 4 different samples and go to the range to shoot some more tests. 3 vials, each 70.0gr weighed on my beam scale:

1. My powder screened -40+70. The same as I used in my first test

2. Goex fffg out of the can. Also, the same as I used in my first test

3. My powder, a blend of 81% -40+70 plus 19% -70+100. This will duplicate the composition of the Goex out of the can.

4. Goex, screened -40+70, which will duplicate the composition of my powder in the first test.

It'll take a day or two to make up the samples. Then off to the range I go. I hope I don't shoot a hole in my chrono before the tests are done.