BP vs Smokless

[w44wcf]

In 1897, the book, THE GUN AND IT'S DEVELOPMENT was first published. The author is W.W. Greener.  There is a chapter entitled INTERNAL BALLISTICS in which the mention of "crusher cylinders" were used to take pressure readings.

I would think that this method of reading pressures goes back to at least the early 1890's when the .30 U.S. Army (.30-40) Cartridge was in development since several powder companies submitted samples to the gov't. for testing. Those powder Co's. (DuPont, Laflin & Rand, California Powder Works) would have to have to have had pressure equipment to test their new powders.

w44wcf

[Driftwood Johnson]

Howdy Boys

Thanks for the answers. In other words, as I suspected the PSI figures for those tests were generated by the crusher method, rather than direct measurement on a gauge. I only point it out because we now know that there is no direct relationship between crusher values and PSI. In some cases crusher values are higher than PSI, in some cases they are lower. Certainly nothing wrong with the crusher method, it is a valid way to measure pressure. But any quoting of crusher values in PSI must be taken with a very small grain of sand, because there is not an exact relationship between crusher values and PSI.

[Delmonico]

Later this week when a few things slow down I'm just curious enough to make a few calls and see if I can find out the exact date that the crusher method was introduced, we are sure now it dates to at least the late 19th Century, no surprise, this Post-Civil War era was not near as primative in many areas as some folks seem to think.   I was sure this was well within the means of the era that the Nitro powders were being developed and hard to imagine development of the loads with out it.

[Driftwood Johnson]

I'll bet you're right. There have been a lot of smart people on the planet for a long time.

[Bryan Austin]

I found some additional information regarding b.p. pressure in the .44-40 while reading an old issue of the Handloader magazine last evening.

In an article entitled  Pet Loads .44-40 Winchester (.44W.C.F.) ,  noted author Ken Waters mentioned this:

"In 1918, Col. Townsend Whelen reported .44-40 chamber pressures as ranging from 13,000 to 15,000 psi with black powder and low pressure smokeless factory loads......." (low pressure smokeless loads at that time used slow burning DuPont No. 2 bulk smokeless whose burning rate is similar to todays 4227)

w44wcf

Certainly he meant cup and not psi!


In my 44-40 testings a few months ago I also recorded data in the 14,000psi mark with original pre-1884 unheadstamped semi-balloonhead cases using 40gr by weight of Swiss FFg. The same exact loads, with different powder compression per different manufactured cases used Between .18"-.21", I recorded 12,000psi in early post 1884 UMC cases and only 9,000psi to 10,000psi in Starline cases...noting that todays SAAMI max pressure listing is 11,000psi/13,000cup.

Also, when Winchester first sold their smokeless loads, the Red Label noted smokeless loads, specifically indicated they were for the Model 1873. The Winchester Model 92 was noted on the side label as well as NOT FOR PISTOLS. Busting the myth that Smokeless was not to be used in the black powder rifles.

From what I can find using much data from Ted & David Bacyk, Tom Rowe, Sharpe and Klaus Neuschaefer, back about 1892 the US military chose from at least 25 smokeless powders/companies to develop loads for the .30-40 Krag. Since the powder companies seemed to flip flop...own one another...for a lack of better words, it's hard to keep up with who is who but all seem to end up at Dupont and Laflin & Rand at some point. Peyton Powder from the California company and Lenard Powder Co. played a large roll. Whistler and Aspinwall's W-A Smokeless shotgun from Lenard Powder seems to be que but I am not sure details. Eventually W.A 30 is what we ended up with. WA 30 came from Lenard, then American, ended up with Dupont under the Laflin & Rand name before L&R was turned over to Hercules.

Anyhow.....the smokeless powder Saga started out about 1892 with the .30-40 Krag but was not offered to the public as W.A. 30 until 1898...of which we all know the new smokeless was used in the new 30-30 in 1894. Civilian vs Military....so true today too huh?

Sharpe explains that California Powder's CPW Smokeless (remember this name) from early 1890's was the same thing as Duponts No.1 Smokeless. It seems somewhat like black powder, smokeless was designated by numbers, 1, 2 and shotgun. Shotgun being the large granular followed by No.1 and then No.2...so to speak...basically the same powder, different granular sizes.

Schuetzen, from 1908 to 1923 was nothing more than 40,000lbs of surplus Dupont No.1. Don't remember who Dupont made that order fore but ended up keeping the out dated powder. Dupont colored the powder slightly orange, canned it old L&R orange cans and created yet another powder name...Schuetzen. Dupont No.1 as well as Schuetzen were true "bulk for bulk" powders created to directly replace black powder loads by volume.

Somewhere in the mix was Laflin & Rands "Sporting Rifle Smokeless" (1894 to 1900) which I think eventually became Dupont No. 2, 17gr of L&R's "SR" was the same as 17gr of No. 2

To add more confusion, somewhere around 1900 all of those L&R powders were disc powder (forget the official word) to include WA 30 which use t be a stick powder (forgot official word). Laflin & Rand created Sharpshooter" powder in 1897 which was first called and labeled "45 Springfield" powder in wood kegs, made specifically for the 45-70. Sharpshooter was exactly the same as W-A 30 but with a different granular...we see that a lot don't we? Sharpshooter was continued when Dupont took over and lasted until 1948. When Hercules took over Laflin & Rand's assests from Dupont through a court order, Shapshooter was also manufactured by them from 1909 to 1914 with a slightly different NG %. Since the two powders were made side by side, L&R/Dupont was known as Sharpshooter #1 and Hercules was known as Sharpshooter #2 although they were not labeled as such. It has been said the Sharpshooter (#1) had a similar burn rate as Blue Dot and 2400 (1937 Sharpe).

Back to the basics regarding early smokeless powders have low pressure curves...yes, this is true with the early smokeless powders, However, there are rumors that Dupont No.2 (Laflin & Rand "Sporting Smokeless Powder" was "dusty" and the dust would settle in the primer pockets and could cause trouble with pressures. THIS could be a reason for the revolver warnings.

Eventually the 44-40 used Sharpshooter, Lightning and SR-80 powders...all rifle powders. Separate loadings for revolvers show up with Unique, Bulleseye and a few others around that 1914 era. Remember the CPW powder from earlier? Yeap, SR-80 is reported to being the same thing BUT with a deterrent added to slow the burn rate and used with great success in the 44-40. SR-80 was a bulk powder but not bulk for bulk like No. 1

With all of that said, many of the loads listed on the powder cans mentioned for the 44-40 show chamber pressures of 16,000 for rifle and 15,000 for revolver....again busting many myths about the 44-40 loadings using revolver and rifle loads. WAIT, 15,000 and 16,000 must have been CUP, not psi. Some load data shows 22,000 as well and we must also assume that is CUP as well.

Add all of this up and we see that early smokeless powders may have been an issue before a burning deterrent was added BUT most if not all rifle powders had a low pressure curve unlike Unique and Bullseye type pistol powders. Some even lower than black powder.

IMR 1204 was a great powder for the 44-40 and was directly replaced by IMR-4227!!

Much of the changes in smokeless powders throughout 1892 to 1900 was creating a powder formula that was not so corrosive but later thought to be the primer problem and not the powder. I saw many entries about barrel corrosion problems with early smokeless powder testing with the .30-40 but then later we see the new non-mercuric primers rather than such powder were more than likely the issue.

As far as pressure, my test data seems to follow early powder data.

18,000psi seems to be close to 22,000cup (my psi loads vs Lyman's handload data in CUP)
13,000psi seems to be close to 16,000cup (my early black powder tests vs early black powder and smokeless powder reported data)
11,000psi seems to be close to 13,000cup (SAAMI Max 11,000psi = 13,000cup)

Sometimes it pays to grab the bull by the horns and fight it!!!!!! Also cost a lot of money!!!!


Kind of makes me wonder why Reloder 7 is such a good powder for the 44-40 rifle!!!

[greenjoytj]

Before Piezoelectric pressure sensors existed the lead (LUP) & copper (CUP) unit of pressure was the tool in use.  The metal slugs used in these pressure testers were calibrated to a known PSI in a look up table.  To use CUP or PSI interchangeably would be natural.

Now that the electronic measurement system is the standard it smart to apply the CUP & LUP label to the measurement as it describes how the measurement was taken.

With the new electronic system capable of showing pressure over time with a vastly faster response time again it natural to add the PSI unit to the measurement to describe the system used.
For the fist time it?s given the engineers a more factual glimpse of what is happening when the cartridge fires.