Black Powder burning rate (pressure curves)

[batteran]

Hello.

I think it can interrest some folks here.

Thats some information (for Vectan french black powder, I'm french, nobody's perfect...):

Curves for 16-bore shotgun, 27g (405 grains) lead, 4,5g (68 grains) black powder (different granulations)

It's metric system, sorry.

PNF1 ~ same granulation as Swiss n°2
PNF2 ~ Swiss n°1

 

[zimmerstutzen]

If the conversion table I found is correct, 100 bar (going up the left) is equal to 1451 Lbs/sq. in.

So the last table that peaks at 500 bar, would be the equivalent of 7,255 psi.

By Comparison, old 45-70 loads were considered max at about 18,000 psi.

Don't know how true it is, but an old timer used to tell me that the approximate safe range with older muzzleloaders in good condition was under 12,000 psi.

 

[Vermonter]

I'd be interested in how this compares to 777 and smokeless.

 

[mr16ga]

Thanks for posting this. Very interesting. If I read the chart right it looks like the max pressure happens at about .9 milli seconds or 900 micro seconds regardless of the size of the powder. I wish I had the setup to take readings like this. It would be nice to know the SD of the data. No apology needed for the SI units. and the little or no difference between PNF1 and PNF2 data makes me wonder if the same would hold true for Fg and FFg granulation's on our side of the pond. Does anyone know how the PNF granulation compares to the F granulation size?

 

[zimmerstutzen]

Vermonter, I remember reading that a few magnum type smokeless high power cartridges were running in the 35,000 to 40,000 psi range. Just can't locate the data now. IIRC, most older smokeless cartridges ran in the 18k psi to 25k psi range.

Found this: Don't know if it helps. Don't know just now how to convert it into a common measure.

http://kwk.us/pressures.html

 

[[email protected]]

Some of my 45 Colt were running in the 52,000 psi range, but we won't go there.

 

[batteran]

Does anyone know how the PNF granulation compares to the F granulation size?

I got that:

PNF4 -> 0,1 to 0,25 mm -> FFFFG (for priming)
PNF2 -> 0,25 to 0,70 mm -> FFFG (handguns)
PNF1 -> 0,30 to 0,80 mm -> FFG (rifles)
P.N. de Chasse -> 0,20 à 1,0 mm -> FFG (hunting powder for shotguns)
Mousquet Tir -> 0,60 à 2,0 mm -> FFG (muskets)

From nobel website: http://www.nobelsport.fr/nobelsport/fr/pf_gamme.html

 

[batteran]

A little conversion to SD units, from left to right:

16-gauge shotgun, 405 grains lead ball, 68 grains black powder:

295m/s : 320 bars -> 970ft/s : 4600 psi
320m/s : 360 bars -> 1050ft/s : 5200 psi
330m/s : 400 bars -> 1080ft/s : 5800 psi
335m/s : 410 bars -> 1100ft/s : 5900 psi
345m/s : 500 bars -> 1130ft/s : 7300 psi

Remember that's smooth bore: pressures (and velocities?) grow higher in rifled bores (more resistance/compression)

 

[Bluehawk]

Some of my 45 Colt were running in the 52,000 psi range

Yer lucky to still have a hand...or both of them...if not worse!!!!!!

 

[rcmodel]

smokeless high power cartridges were running in the 35,000 to 40,000 psi range.

Way more then that!

A 30-30 Winchester runs in the 40,000 range.
Most common bolt-action calibers run around 50,000 to 60,000.
A few run 65,000.

See this about that:
http://www.leverguns.com/articles/saami_pressures.htm

rc

 

[Pete D.]

Pressures

I remember reading that a few magnum type smokeless high power cartridges were running in the 35,000 to 40,000 psi range.

The big .416 Rigby runs at 40Kpsi
The newer .416 Remington runs up to 65K psi.
The venerable .30-06 runs up to 60K psi. The .308 Win to 65K psi.
The .300 RUM runs into the middle 60ks psi.

Typical smokeless shotshell pressures are between 7K psi and 11K psi (12 ga.)


Pete

 

[mr16ga]

Some of my 45 Colt were running in the 52,000 psi range, but we won't go there.

I would not pull the the trigger with one of those loaded in my TC Contender or Ruger. Those are HOT rounds for a .45 Colt. Be careful of where you store them as they would shatter an old Colt or clone of one.

 

[makos_goods]

I would not pull the the trigger with one of those loaded in my TC Contender or Ruger. Those are HOT rounds for a .45 Colt. Be careful of where you store them as they would shatter an old Colt or clone of one.

Which is why you shouldn't shoot anything but Gunpowder in an old Colt's SAA. That even includes a lot of the post 1896 models once they started marking them with the "VP" (Verified Proof) symbol to designate they were capable of shooting nitrocellulose powder. Steels were constantly getting better up until the 2nd World War.

A lot of knowledgeable people in the early 20th century used to recommend using Semi-Smokeless powder in old SAAs before it went out of fashion and ultimately production in the '30s. You used to be able to get .45 Colt, .44WCF, .38WCF, etc. cartridges made by UMC, Peters, Winchester and others with powders like Lesmok (semi-smokeless), or King's.

The beauty of Gunpowder is that you really can't overload a pistol cartridge, and the pressures generated are benign.

Why are we discussing nitrocellulose pressures and powders, I thought this was the BP forum on this site? Batteran's original post is useful to help with our understanding of BP and why it differs from Nitrocellulose.

For the last several years I have been reading with some concern about the growing use of substitute gunpowders like 777 in weapons it was not intended to be used in. We might be doing a disservice to many of the less experienced readers if we act like it is no big deal and especially if they have been using gunpowder as it was intended. That is either a full compressed case of FFg or even FFFg of real gunpowder or a recommended measure of BP in a percussion pistol.

Modern Inlines are extremely strong and that is the intended market for the newer substitutes. A oft repeated warning about use in pistols or even toggle link rifles is probably in order.


~Mako

 

[andrewstorm]

makos?

{the beauty of gunpowder is you cant over load it)? i think you mean blackpowder.......

 

[makos_goods]

noise deleted

 

[mykeal]

Historically, gunpowder is what we now (since about the late 19th century) call black powder. The term black powder came into use in order to distinguish historical gunpowder from the newer semi-smokeless powders. Strictly speaking, gunpowder and black powder are the same thing, while semi-smokeless, smokeless and synthetic black powders are not gunpowder. However, the term gunpowder is now often used in a more general sense to refer to the category of materials used as propellants. It's entirely possible that someone unfamiliar with the subtleties of the lexicon (as the vast majority of us are) would infer smokeless powder from the word gunpowder; in the context of:

The beauty of Gunpowder is that you really can't overload a pistol cartridge, and the pressures generated are benign.

that could be a fatal mistake. The (now) more precise term, black powder, or perhaps even better, real black powder, would lessen the likelihood of that error.

 

[makos_goods]

noise deleted.

 

[mykeal]

Seriously, is this really the level this forum needs to converse in?

Yes.

 

[Norton Commando]

Quote:
Seriously, is this really the level this forum needs to converse in?

Yes.

Ditto

 

[makos_goods]

noise deleted