Some, but not all(!), smokeless powders have a slower pressure spike than b.p.

[w44wcf]

Thank you to DuckRider who posts on another forum, here is now proof that the proper smokeless powder will give a slower rise in pressure than black. The rise time is in milliseconds showing that b.p. spikes quicker.
 


Sincerely,
w44wcf

[Cuts Crooked]

Thank you to DuckRider who posts on another forum, here is now proof that the proper smokeless powder will give a slower rise in pressure than black. The rise time is in milliseconds showing that b.p. spikes quicker.
 

Sincerely,
w44wcf

That's cool! Thanx fer the info pard!

I do note however that he was comparing apples and oranges, using a 500 gr projectile for the BP loads and a 410 grain bullet for the smokeless load. But the key words here are "proper smokeless powder" and knowing what that is can be the real crux of the matter in loading smokeless in place of BP! Without a good ballistics lab one has no way of knowing that with any given cartridge/load combination. And I've
learned the hard way that exptrapolating from data developed with different componants can and will fool ya!  I'm sure many here have seen data that I haven't and I have seen some down through the years that maybe others haven't. I do recall on more than one occassion reading data that indicated that given smokeless loads approximate BP loads in pressure, but....some of them show a totally different "pressure wave" that spikes quicker. I think I'll stick with published loads from a well known source in ANY cartridge! Call me a chicken if you will! I'm kinda partial to my eyeballs and my hands!

[Montana Slim]

Is there a direct link to the post / data ?

I'm curious if DuckRider is using EPVAT equipment or one of the "fancy" chronographs on the market.
I'd also like to know what the units are for the "pressures" listed in the tables.

I have seen instances where test equipment (yes, for cartridge pressure) was not sensitive enough to record peak pressures within the miliseconds of the phenomena. This was in some pretty "high-dollar" labs, to boot.

If ya'll hadn't guessed, I am a bit skeptical.

Regards,
Slim

[w44wcf]

Cuts Crooked,
You are most welcome. Yes, I did see the bullet weight difference. I am contacting DuckRider to see if he would run a test using the 500 gr. bullet and also with 28 grs. of 4198 (40% of b.p. weight of 70 grs.)  Other than raising the pressure slightly, I doubt that there will be much of a change in the millisecond rise time.

Historically speaking, the first "low pressure" smokeless used in the .45-70 was DuPont Bulk smokeless No.1 (28 grs.) which had a burning rate very similar to 4198. 

After about 1900, , 20 grs. of "Sharpshooter" was the factory .45-70 smokeless loading for many years. "Sharpshooter" has a slightly faster burning rate than 4759.

As you indicated, the key words are the proper smokeless powder. DuckRider also ran a test with Trailboss, a much faster burning smokeless.  The milliseconds rise is as fast a b.p. and the pressures are much higher, and the velocities lower. NOT the proper smokeless powder to use  to duplicate b.p. velocities!! 

Thank you to DuckRider for this data.

[w44wcf]

Montana Slim,
Yes, Here's the link:
http://www.assra.com/cgi-bin/yabb/YaBB.pl?num=1202959756

DuckRider used an Oehler system.  Pressure example 182 = 18,200.

Since the same rifle / system was used for all the data the comparison is valid.

I have seen instances where test equipment (yes, for cartridge pressure) was not sensitive enough to record peak pressures within the miliseconds of the phenomena. This was in some pretty "high-dollar" labs, to boot.

Yes, I have seen the same thing where pressures were too low to be recorded (below 6,000).  That is not the case here.

Thank you for your interest.

w44wcf

[Tubac]

Gents,

Interesting data, but I'll still stick with Black Powder.

Tubac

[Hobie]

Very interesting and the info about Trail Boss is much what I expected. 

[Adirondack Jack]

Very interesting and the info about Trail Boss is much what I expected. 

TB is a pretty durn FAST pistol powder.  Nothin to be confused with slower stuff, just because it's bulky.

[Cuts Crooked]

Well, I have some loads published by Lee that use Blue Dot or H322 for45-70! These are NOT loads I would run in an old gun, by any stretch of the imagination! (in truth, I would be hesitant to put some of them in my modern made Roller!)

But I note a certain segment of the shooting population that doesn't like to use black powder (misguided souls I fear ) in guns originally designed as BP shooters. My concern would be that some new reloader would extrapolate from data like the above, trying to apply it to another cartridge, and get into real trouble with an old original gun. Yes I know that drawing conclusions about one load based on data developed in another load is DANGEROUS, unfortunately there are some folks who will do jist that!

So, I still say I appreciate the date Duckrider has provided, but I add that this stuff is not for the inexperianced and should be approached with caution even by those of us who think we have little to learn anymore! As always, load data found on a web board is only worth what you paid for it and you assume full responsibility for the risks entailed in using it!. IE: there is some extremely good info out here in cyber space, but there is some bad stuff too! You have to decide fer yerself pards!

[Adirondack Jack]

Well, I have some loads published by Lee that use Blue Dot or H322 for45-70! These are NOT loads I would run in an old gun, by any stretch of the imagination! (in truth, I would be hesitant to put some of them in my modern made Roller!)

But I note a certain segment of the shooting population that doesn't like to use black powder (misguided souls I fear ) in guns originally designed as BP shooters. My concern would be that some new reloader would extrapolate from data like the above, trying to apply it to another cartridge, and get into real trouble with an old original gun. Yes I know that drawing conclusions about one load based on data developed in another load is DANGEROUS, unfortunately there are some folks who will do jist that!

So, I still say I appreciate the date Duckrider has provided, but I add that this stuff is not for the inexperianced and should be approached with caution even by those of us who think we have little to learn anymore! As always, load data found on a web board is only worth what you paid for it and you assume full responsibility for the risks entailed in using it!. IE: there is some extremely good info out here in cyber space, but there is some bad stuff too! You have to decide fer yerself pards!

Aye, as ole Elmer once said, wandering beyond published load data is for the man who knows what he is about.  If ya have any doubts, DON'T

[Dick Dastardly]

Yes, in some loads and some situations, there are smokeyless fad heathen powders that will give a "softer" pressure rise.  But, aside of not being Holy Black, what is the advantage in them.  It is KNOWN that black powder pressures are very manageable, work in antique guns as well as modern ones & are very safe to the novice compared to heathen fad smokeyless as pertains to hand loading.

So, to make a simple representation to encompass smokeyless vs black and pretend that it is universal is very dangerous.

Now, I know that w44wcf never intended a novice to take his post as a blanket statement that smokeyless is "softer", or has a lower, slower and more gentle pressure curve.  But, there are those that would take the data presented and postulate loads that might very well be pipe bombs.  His data does, however, point up the obvious conclusion that, with careful study, there are very safe heathen fad smokeyless loads that will approximate black powder performance.  For this he is to be commended.

Thanks for the data w44wcf.  We will continue to treat it with the respect you intended.

DD-DLoS

[w44wcf]

DD,
Thank you for the kind words.  Ever since the  "pressures of b.p. /smokeless" thread last year regarding the pressure spike between the two http://www.cascity.com/forumhall/index.php/topic,15307.0.html   I have been trying to find some data.  My thanks again to DuckRider for the information.

As we know there are many different burning rates of smokeless.  As the data shows, there are slower burning types that have a slower pressure rise than black and faster type(s) that not only have a pressure spike as fast as black but develop higher pressure as well.  Based on the data,  the slower types are certainly safe in b.p. guns, the faster types are not(!!).

That being said, I like b.p. and enjoy shooting it and I also like smokeless, especially in older guns with pitted barrels.

Sincerely,
w44wcf

[Steel Horse Bailey]

I'm gonna put in my (probably worthless) 2 cents.  (It sure won't buy much gas anymore, so $.02 must NOT be worth much!  )


I, too, appreciate this research and the information you provided, DuckRider.  The problem is, unless you happen to use this particular powder and bullet combination, and I don't know how popular this particular powder is (I'm not much of a rifle loader - if it doesn't use BP or IMR 4198 I don't know much about it!) this data only serves to prove that under at least ONE detail, that a smokeyless powder can, under EXTREMELY limited situations have a spike lower than Goex 2f and 3f.  I'd be interested to see how that compares to more popular powders that many use.  What I mean is - is this a small difference (the pressure spike) between the powder figures, or is the BP as much higher than IMR 4759 than other smokeless powders are over BP.  Putting it differently, would the figures from the 4759 look like those produced by BP, - or smokeless - if a whole BUNCH (I know, bananas grow in bunches) of different pressure spikes were compared. 

The information is certainly something of an eye-opener to ME!  I didn't realize that ANY smokeyless powder could have a lower spike than BP!  I just hope that no idjit experimenter decides that now there is PROOF that smokeyless powder spikes lower than ALL BP, he can now fill up his 45-110 with Bullseye, R-1, W231 or whatever and he'll be all right in Grandpa's prized unissued Trapdoor Springfield!

People like that DO exist - The annual Darwin Awards prove it.

[Hobie]

TB is a pretty durn FAST pistol powder.  Nothin to be confused with slower stuff, just because it's bulky.

But we have seen people apply it to rifle cartridges, even the .45-70, because of this bulky characteristic. 

[Ranch 13]

  Thanks for posting the good info. Next time someone starts in to kickin my teeth in on account of my saying trailboss is entirely to fast to use in a center fire rifle cartridge bigger than the original wcf series I'll have something to point them too.

[Adirondack Jack]

FWIW, Trail Boss is only a few notches slower than Bullseye or 700X on the burn rate charts.

It is faster than Green Dot, HP38, Unique, etc.

IMR SR 4759 is one of the "bridge" powders, very slow for handguns, very fast for rifles.  It's just slower than 4227 and H110.

Two entirely different animals for which NO conclusions can be drawn other than to say "when loaded lightly, some powders might be OK in place of BP".  Many will never be OK, and even those that are when loaded just so, might not be if they are loaded "up the ladder" where progressive burns start making more absolute pressure.

I appauld the efforts to show what can be done, but the TITLE of this thread is what some folks may remember, and might could easily get hurt.  If the durn gun ain't proofed for smokeless, DON'T USE IT.

[Dr. Bob]

AJ,

You said it all!  IF IT ISN'T PROOFED FOR SMOKLESS, USE ONLY HOLY BLACK.  A blown up revolver and mangled hand are real expensive and no fun at all.  Be SAFE!!

[w44wcf]

Adirondack Jack,
Thank you for your input. I reworded the title.

Folks,
ALWAYS consult your reloading manual for reliable loading information!

In this case, the 23.0 gr of 4759 is a published  load in the Lyman cast bullet handbook.
Lyman shows 1,207 f.p.s. / 15,700 C.U.P. under a 420 gr. bullet.

By comparison, Lyman shows 70.0/FFG under the same bullet at 1,268 f.p.s. / 16,400 C.U.P.

Also shown is data for 4198 which is slower burning than 4759 and which virtually duplicates the b.p. load at less pressure.
28.5 / 4198 / 1,267 f.p.s. / 13,900 c.u.p.

I like b.p. as much as everyone here, and based on the data in this thread, if you must use a smokeless powder to replicate b.p. velocities, Stay away from fast burning smokeless powders  (faster burning than 4759) because pressures can run too high!

Stay safe pards!
w44wcf

[Adirondack Jack]

Adirondack Jack,
Thank you for your input. I reworded the title.

Folks,
ALWAYS consult your reloading manual for reliable loading information!

In this case, the 23.0 gr of 4759 is a published  load in the Lyman cast bullet handbook.
Lyman shows 1,207 f.p.s. / 15,700 C.U.P. under a 420 gr. bullet.

By comparison, Lyman shows 70.0/FFG under the same bullet at 1,268 f.p.s. / 16,400 C.U.P.

Also shown is data for 4198 which is slower burning than 4759 and which virtually duplicates the b.p. load at less pressure.
28.5 / 4198 / 1,267 f.p.s. / 13,900 c.u.p.

I like b.p. as much as everyone here, and based on the data in this thread, if you must use a smokeless powder to replicate b.p. velocities, Stay away from fast burning smokeless powders  (faster burning than 4759) because pressures can run too high!

Stay safe pards!
w44wcf

For those interested in the history of LOW PRESSURE smokeless loads and their uses, military, clivilian, and "spooky", do ya a little searchie on "cat sneeze" loads.  From clandestine ops to suburban pest control, low pressure, very low velocity loads for rifles have been around for some time.