BP vs Smokless

[Pomona Pete]

I am curious about pressures.  Does a handloaded BP 45 Long Colt cartridge have the same pressure as a factory loaded Winchester CAS 45 long colt cartridge.  Thanks

[Dick Dastardly]

250 GR. CAST LRNFP      250      231      .452"      1.600"      5.8      785      9,100 CUP      7.1      916      13,900 CUP

That's the data from the Hogden calculator.

Here's the Hogdon data.

250 GR. CAST LRNFP      250      HS-6      .452"      1.600"      9.0      787      7,800 CUP      10.5      946      13,300 CUP              
250 GR. CAST LRNFP     250     Universal     .452"     1.600"     6.5     742     9,200 CUP     7.8     941     13,000 CUP          
250 GR. CAST LRNFP     250     HP-38     .452"     1.600"     5.8     785     9,100 CUP     7.1     916     13,900 CUP          
250 GR. CAST LRNFP     250     Titegroup     .452"     1.600"     5.0     716     7600 CUP     6.2     881     13,000 CUP          
250 GR. CAST LRNFP     250     Clays     .452"     1.600"     4.2     713     8,500 CUP     5.1     817     13,400 CUP          
250 GR. HDY XTP     250     HS-6     .452"     1.595"     9.7     743     9,700 CUP     10.8     862     13,500 CUP          
250 GR. HDY XTP     250     Universal     .452"     1.595"     7.5     705     10,300 CUP     8.5     856     14,000 CUP          
250 GR. HDY XTP     250     HP-38     .452"     1.595"     6.5     692     10,500 CUP     7.3     797     14,000 CUP          
250 GR. HDY XTP     250     Titegroup     .452"     1.595"     5.5     739     9700 CUP     6.3     830     12,700 CUP

The 45 Colt cartridge loaded up with 37 grains by volume of your favorite black powder and a 250 grain lead bullet will run around 9000 psi.  It will graph at around 900 fps.  This is a good load and should be safe for your guns.  As you can see above, the smokeless does usually run higher pressures.

If you go to Pyrodex or some other sub/replica, you are on your own.

Hope this helps.

DD-DLoS

          

[Adirondack Jack]

The trick to BP is it holds pressures LONGER, giving more the sustained push VS the sudden whack of higher pressure, but shorter duration smokeless burns.

[Pomona Pete]

Thanks to everyone for the responses.  I guess I should rephrase the question.  Are the Winchester CAS loads safe to shoot in original guns in good condition chambered for that cartridge?  Thanks again..

[Driftwood Johnson]

Howdy

Here is a graph showing the pressure curves of two different shotgun loads, each achieving the same velocity with the same shot charge, one being a Black Powder load, the other a Smokeless load. Note this is not a graph of pistol ammo, but shotgun ammo. Still, it illustrates what AJ just said very well. Notice how the Smokeless curve peaks much higher and is of a much shorter duration than the Black Powder curve. The burning characteristics of Smokeless powders result in this much sharper, and more intense pressure spike. This is the reason that older guns, not proofed for Smokeless powder should not be shot with modern Smokeless loads. Even when the velocities are kept low, the pressure spike will still be sharper and more of a shock to the old steel than a BP load. The more stretched out pressure curve of BP is also responsible for what many term the shove, or push of Black Powder recoil, vs the sharp smack of Smokeless recoil.

[Driftwood Johnson]

What do you mean by 'original guns'?

Colt did not factory guarantee their revolvers to be safe to be shot with Smokeless Powder until 1900. A quick search of Serial Numbers will tell the date of manufacture of old guns. Up until that time, Colt did not feel the steel available was strong enough to be used with Smokeless powder, and most students of Colts agree, Colts older than 1900 should only be shot with Black Powder loads, no matter how light the Smokeless loading might be. Sometime in the 1930s Colt started using even stronger steel when the SAA was first chamberd for the 357 Magnum cartridge.

I don't have figures for other manufacturers, but I doubt if any or them had access to better steel than Colt did up until 1900.

Revolvers are one thing. They are relatively weak by nature, because the chamber walls are relatively thin. I have an old Marlin that was manufactured in 1895, and I'd bet it was only proofed for Black Powder. However when I was young and foolish and before I knew any better I did put some relatively hot Smokeless 44-40s through it. Rifles will be stronger then revolvers simply because of how much thicker the chamber walls are. So I probably did not damage my old Marlin. Still, when I mentioned it to a gunsmith he winced in pain, mentioning that the old steel might have gotten compressed by the higher pressure loads. However I still do shoot that Marlin, and a Winchester of the same vintage with light smokeless loads.

Shotguns are still something else again. Shotguns have very, very thin chamber walls by nature. I would not shoot any shotgun with Smokeless powder, no matter how light the load, unless it was specifically marked as Nitro Proofed.

Some of the preceding is fact, some is simply opinion. Do as you see fit. The 1900 date for Colts is fact.

[Paladin UK]

Wow!!
What an innerestin thread this turned out ta be!!!
There sure is a whole wealth of knowledge hanging around the saloons here abouts!!


Paladin (What lurvs the Holy Black `n the... Sloooooooooooooooooooooow Boooooooooooom!!!  ) UK

[Steel Horse Bailey]

Howdy!

Pomona Pete, there's good info here.  DJ again has a good illustration showing what DOES happen, not just what we THINK.

I'd keep those pre 1900 guns using ONLY BP rounds, NOT BP "equivalent" smokeyless loads.  The shotgun graph is a perfect example of BP "equivalent."  The end performance is the same (velocity & shot) but how the rounds ACHIEVE that performance is vastly different!

[w44wcf]

I am curious about pressures.  Does a handloaded BP 45 Long Colt cartridge have the same pressure as a factory loaded Winchester CAS 45 long colt cartridge.  Thanks

I would say that the pressures would be similar,  although the b.p. cartridge will give the higher velocity.  The reason is that the factory Winchester CAS cartridge uses faster burning smokeless ....... similiar to Bullseye in burning rate.  Now if one reloads the .45 Colt with slower burning smokeless powders (4227, 5744, RL7), the velocity and pressure would be similiar to b.p.

In Driftwood Johnson's example, the pressure affects of faster burning smokeless can be seen. Had the proper burning rate of smokeless been used, peak pressure and velocity would be pretty much equal with b.p.

If one looks at the Lyman cast bullet handbook, there is an excellent reference section on both b.p. and smokeless in both pressure and velocities in the .45-70 which proves out the above information.

Have fun.

w44wcf

   

[w44wcf]

UPDATE:

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)

Pressures of original factory loaded .45 Colt b.p. cartridges (40 grs. b.p.) would be similar (Original .45 Colt UMC cartridges clocked 1,241 f.p.s. in my Marlin's 24" barrel).

To DD's point that b.p. pressures would be around 9,000 p.s.i., that would be true with a reduced load of b.p. and little powder compression, which in turn would = lower velocities than the early factory loaded b.p. cartridges and = velocities to the ones produced by the faster burning smokeless powders in DD's post.

However, as mentioned previously, if slower burning smokeless powders are used, pressures between b.p. and smokeless are similar with smokeless sometimes producing less pressure to = similar velocities as this example from the Lyman "Cast Bullet Handbook" on the .45-70 shows:

Bullet weight 420 grs.
70.0 grs./   FFG / 1,268 f.p.s. / 16,400 C.U.P.
28.5 grs./ 4198 / 1,267 f.p.s. / 13,900 C.U.P.
38.5 grs./ 3031 / 1,352 f.p.s. / 16,000 C.U.P.

w44wcf

     

[Driftwood Johnson]

w44wcf

I am really curious. The information you are posting seems to fly against conventional wisdom regarding BP pressures vs Smokeless pressures. If Smokeless pressure was essentially no greater than BP pressure, then why did Colt choose not to factory guarantee the SAA for Smokeless Powder until 1900, at which time suitable steels had been developed that could withstand the greater pressures generated by Smokeless powders?

On a side note, do you know what kind of instrumentation was used in 1918 to determine chamber pressure, specifically psi and not cup? Just curious.

[w44wcf]

DJ,

Good question. I don't know, but can only speculate that perhaps they weren't convinced that the new (at that time) factory smokeless cartridges were safe for use in their sixgun.  I would suspect that the new smokeless powders were looked upon by some as "vodoo" and not to be trusted.

DuPont No. 1 and Dupont No. 2 bulk smokeless powders were patented on August 22, 1893.  They were tan colored granular powders and DuPont's designation of them as "bulk" smokeless powders was already familiar to black powder shooters since they loaded  their  black  powder  charges  by  bulk  measure. These powders were designed to be also loaded by bulk measure.   

DuPont No. 1 bulk smokeless was meant for the larger rifle cartridges. In the .45-70,  28 grs. occupied the same space as 70 grs. of b.p.  Dupont No. 2 bulk smokeless was intended for the smaller cartridges. In the .44-40. 17 grs. occupied the same space as 40 grs. of b.p.

Winchester Repeating Arms ballistics lab worked with them for over a year before coming out with their smokeless option  for b.p. cartridges in 1895.  Winchester's biggest competitor, UMC (Union Metallic Cartridge), introduced their smokeless line of b.p. cartridges in 1896.

Back in the December, 2000, Cowboy Chronicle, there was an article I had  written under the name of "Jack Christian" entitled "Gunpowder Trails...1890's Smokeless Powder Options For Black Powder Cartridges" which introduced the reader to the earliest smokeless powders which were of the "dense" type and why they weren't safe for use in lower pressure b.p. cartridges.  DuPont solved that problem with the introduction of their "bulk" smokeless No. 1 & No. 2 powders.

Hopefully I will be able to purchase some pressure trace equipment next year and accumulate some actual data, specifically for b.p. loads in the .45 Colt.  Then we'll know for sure.

Unfortunately, I do not have any informatuion regarding the use of the pressure equipment used in the early days, but I know of someone who might. If I find out anything, I'll add it in another response.

Early Winchester .44-40 Smokeless box indicating their use in both the '73 & '92 WInchester rifles.



w44wcf

   

[Dick Dastardly]

Thanks w44wcf,

Your data is well taken, but I'll stand by mine.  I haven't found any SASS loaders compressing more than 37 grains of Holy Black compressed by 250 grain bullet seated to factory OAL.  Maybe you could trickle the charge thru an drop tube, vibrate the hull some and use a compression die to the max on the thinnest new factory hulls available and then get close to 40 grains inside a modern 45 Colt hull.  But, I've found that a more common compressed charge of 37 grains of bp will give good ammo that will run around 900fps out of a PISTOL.  That load will churn up around 9000 psi.  The same bullet loaded to that velocity and carefully chosen heathen fad smokeyless powder will give generally higher pressures with some of them going over 16,000 psi.

Black powder has a far different time/pressure curve, as stated by DJ, and the resulting force isn't near as sharp.  It's kind of like striking a bell with a steel hammer and hitting it with just as much force using a wood hammer.  Different impact, different sound, different result.  One will dent the bell, the other will merely ring it.

Smokeless powder cartridges were the big ammo manufacturers way of getting into the pockets of the reloaders.  About that same time "Staynless" primers were also introduced.  The only place they could be had was in factory loaded ammo.  Thus the more corrosive primers available to handloaders gave Black Powder a bad rap.  Now, it's become common knowledge that guns that have shot bp can wait a while before getting cleaned.  The primers now used for black powder loads are non corrosive.  It wasn't the powder, it was the primers.  I know that this is off the mark on the pressure discussion, but I feel it's worth saying because there's a lot of myth out there about the corrosiveness and inconvenience of black powder.  Thanks for your indulgence.

DD-DLoS

[Delmonico]

Dick, I need to do a little research, but I think the pressure testing at that time was the lead and copper crusher type.  I know when the strain gauge type came into being the older type was refered to as 19th century technolagy.  I'll do some checking.

[w44wcf]

DD,
Thank you for the "thanks".

I would agree that your 37 gr. load in current brass would be a fine load under a 250 gr. bullet.  For those who want to load the full 40 gr. into a modern case, Swiss b.p. is the answer.  It is 10% more dense than Goex and, thus,  a 40 gr. charge of Swiss will fill the case to a little less than the same level that 37 grs. of Goex will.    

One wonders how Goex loaded 42 grs. of their powder into a .45 Colt case(??)......must have used a heap amount of compression! Interestingly, the ballistics are sub par for that amount of powder used.   http://www.goexpowder.com/load-chart.html

One of the smokeless powders I like in the .45 Colt is Herco. 9grs. gives 910 f.p.s. at 12,600 c.u.p. according to Alliant.

The pressure / velocity data for the .45-70 taken in the Lyman ballistics lab clearly shows that the proper smokeless powders are on par with b.p. regarding velocity / pressure. The .45 Colt cartridge is a different cat, so to speak and I agree with your assessment of approx. 9,000 psi with 37 grs. of Goex.  40 grs. of Swiss will increase that, and the velocity as well.

Regarding the time / pressure curve, my thoughts are that the b.p. wiill give a sharper initial spike, otherwise, I am at a loss to explain why b.p. will bump up a soft lead bullet, whereas, smokeless powder won't. That has been my experience.

Interestingly, I ran a test a few years back in the .44-40 using a rifle with a 21" barrel and another with a 24" barrel.
Note the higher velocity increase with both 4227 & RL7 powder as compared to b.p. which would indicate that they would have the flatter pressure curve.

40 grs. Swiss FFG - velocity increase 19 f.p.s.
21" -1,273 f.p.s.
24" -1,292 f.p.s.

16 grs. H4227 - velocity increase 58 f.p.s.
21"- 1,177 f.p.s.
24"- 1,235 f.p.s.

25 grs. RL-7 - velocity increase 109 f.p.s.
21" - 1,258 f.p.s.
24" - 1,367 f.p.s.

Testing in 2008 with pressure trace equipment using my .45 Colt '94 Marlin Cowboy rifle will give us some accurate information.  Stay tuned.

Regarding primers: Mercuric priming was used in the first b.p. cartridges. They were hard on brass, but not barrels. Then, in the early 1900's, priming compound containing potassium chlorate entered the picture.  These were corrosive primers which could ruin a barrel in short order if it was not cleaned properly.  Remington "Kleanbore" priming introduced in the mid 1920's were the first non corrosive primers. Winchester followed 5 years later with their "Staynless" brand of primers.

To your point, yes indeed, if one fired b.p. cartridges with the corrosive primers and didn't clean the barrel properly, bad news, and as you said, b.p. could be incorrectly blamed.  Not too long ago, after firing b.p. cartridges in my .357 Marlin, I didn't clean it for over a week. When I did there was no sign of corrosion at all.

Sincerely,
w44wcf


   

[Driftwood Johnson]

Delmonico

I asked the question about pressure instrumentation becase the figures were given in PSI. I understand earlier pressures may have been obtained with the crusher method. I wanted to know if there was a pressure guage available for the 1918 data that could capture cartridge pressure information. Obviously pressure gauges have been around since the early days of railroads, I just wonder if they could capture fleeting data like the pressure of a fired cartridge.

[Delmonico]

Turn of the century data I've seen is often given in PSI.  I know today we know the lead and copper crusher methods don't give exact PSI but a ball park figure somewhat near PSI, depending on the shape of the cartridge.  Curiosity has gotten to me, but so far no search has showed up exactly what they used. I would still guess the copper/lead crusher method, it should be within the technolagy of the late 19th century.  I wonder if the answer would come to light with a couple phone calls rather than search engine one.  Have tried several search engines and several different wordings and nothing yet for sure.

[w44wcf]

DJ & Delmonico

Don't know why I didn't think of this sooner.......I consulted Phil Sharpe's book "Complete Guide To Reloading" which is a wonderful reference for much more information than just reloading.

Anyway, at the time this book was published (1937) he states that in pressure guns for cartridges generating under 15,000 p.s.i.,  lead crusher cylinders are used.  Over 15,000 p.s.i., and copper crusher cylinders are used. These crusher cylinders shorten in the testing process. "This shortening is measured in thousands of an inch and translated by means of the chart prepared especially for each lot of crusher cylinders into a breech pressure reading pounds per square inch. This chart is known as a tarage table." 

I googled "Tarage table" and found this publication "Ordnance and Gunnery 1917".  Chapter III deals with  Measurements of Velocities and Pressures. It can be purchased for $2.50 + $6.00 mailing. Should be interesting & informative.
http://military-info.com/Aphoto/Tschappat17.htm

w44wcf

[Dick Dastardly]

Yup, CUP & LUP means Copper Upset Pressure and Lead Upset Pressure.  Not the same identical results as strain gauge or pizo electric.

DD-DLoS

[Delmonico]

But now I am still curious, when in heck was the thing ivented and when did it come into use with ammo companies.  It almost had to be in use for them to safely develope Nitro ammo, either that or they scattered a lot of guns around the test rooms..