Author Topic: powder selection  (Read 7355 times)

The other DWS

  • Guest
powder selection
« on: March 22, 2012, 06:10:06 AM »
What principles govern the selection of powder grain size (F though FFFF)     I know that the smaller the grain the quicker it ignites/burns.  I know the general recommendation is for 3F for bores up to 60 or so then 2 F above that.    Does barrel length factor in, or charge volume? 

 I assume that you want complete combustion with the peak pressure occurring just before the ball exits the barrel.  Unlike "conical" projectiles the weight of the round ball is fixed in a direct reflection of the bore diameter.  I know that some ML pistol shooters recommend using 4F to get maximum power out of the short barrels.

Offline LH

  • Full Member
  • ***
  • Posts: 222
Re: powder selection
« Reply #1 on: March 22, 2012, 01:13:35 PM »
I dont think most shooters are very scientific about choosing powder granulations. I shoot flintlocks almost exclusively, so I use fffg because it lights and burns fast which helps my offhand shooting and I can get target accuracy with it.  The only gun I shoot ffg in is a .58 that I only occasionally hunt with and the reason I use ffg is for the extra power I can get with big charges (90 or more grains)  But since they closed the rhino season here in Ga.  I dont shoot it that much.   ;D

omark

  • Guest
Re: powder selection
« Reply #2 on: March 22, 2012, 06:04:46 PM »
they closed rhino season????????????    darn it, anyway.     ;)    mark

northmn

  • Guest
Re: powder selection
« Reply #3 on: March 22, 2012, 08:25:17 PM »
A lot is rule of thumb.  3f is considered used up to about 45 cal but many liked 3f for target shooting up to 58's.   When I chronographed I found 2f to be more consistant in my 54 in velocity from shot to shot.  Also for heavy charges 2f gives less pressure.  I still got excellent results with 3f in my 50 even at 80 grains for hunting.  I also like 2f in my larger bore flintlocks as I use a .070 touch hole and 3f can be a little self priming.  When I shot a lot of target matches, "they" were telling me that 3f fouled less so I used it.  Whiel I was fairly successful, knowing what I know now I might have experimented with 2f and lubes as I think in heavier loads it should be more accurate.  I am thinking about a Green River 58 barrel I had that did not seem to want to shoot as well as it should.

DP

The other DWS

  • Guest
Re: powder selection
« Reply #4 on: March 23, 2012, 12:26:22 AM »
From what I'm gathering, (correctly I hope) it appears that "fouling problems" may be largely a function of bore/ball/patch fit combined with lube.   Fouling as I understand it, is the incompletely consumed powder residue left in the barrel after the shot.  Much of ML shooting has to deal with a "work-around" for loading following shots by "managing" the fouling with patches and lubes (and in the case of BPCR guys using blow-tubes to keep the fouling soft with more humid air from one's lungs".

Can re reduce fouling by manipulating the powder grain size?
 It seems quasi-logical to my uneducated mind that a finer grain powder might burn faster/hotter/more completely than a coarser one.  I guess the issue becomes finding the balance of burn rate for ball diameter/ball weight factoring in the bore condition and twist (degree of friction) AND barrel length.   Ball weight is of course dictated by bore size.  We can vary the powder charge, powder grain size, and to some degree the friction with the patch and lube.   Then of course you have to balance the velocity for maximum accuracy.

this whole thought process got started because I've been wondering how the .29 would react to the use of 4F as a main charge but I fear that with a 40" barrel it'd wind up peaking too soon and not generate enough O2 to get a complete burn without using larger charges than reasonable.  It  might work better in a shorter barrel?


Dave Faletti

  • Guest
Re: powder selection
« Reply #5 on: March 23, 2012, 01:54:39 AM »
Are you trying for a hunting, or target load?  For a heavy hunting load use the appropriate granulation for the bore and try for velocity and decent accuracy.  For moderate hunting or target its not uncommon to drop down to the next finer granulation for cleaner burning, economics and possibly accuracy. 

Any decent barrel length will have as complete  of combustion as that load will give. 

Barrel length has no bearing on when the pressure peaks.

I wouldn't use 4F as a main charge.  That seems like asking for pressure problems though someone else may have loads and pressure data for using it.


Fred_Dwyer

  • Guest
Re: powder selection
« Reply #6 on: March 23, 2012, 08:31:48 PM »
Quote
with the peak pressure occurring just before the ball exits the barrel.

I don't think is is like that. Take a look at a shotgun barrel, smoky or smokeless; they are thinnest at the muzzle. If pressures peaked out there, there'd be more 'meat' in the muzzle end. Later in this thread you brought up BP pistols. OK, let's look at that. If we can get 800 feet per second out of an 8 inch .45 pistol barrel, and 1600 fps out of a 38 inch rifle barrel; where do you think the peak pressure (and acceleration) is developed?

Quote
I know that some ML pistol shooters recommend using 4F to get maximum power out of the short barrels.
Maybe. But does power equate to accuracy?

It comes down to each gun has its' own like and dislikes; and you'll never know until you try different loads in your gun and measure some groups. That's part of the fun, different powder, lube, patch, ball, and even brand of powder. All you can do is save your targets labeled with each set of variables, pick the combination that does best for you.
Ballistics is not a matter of calculations, ballistics has always been a series of measurements. After a mess of measurements you can make some assumptions but not many calculations.




Offline LH

  • Full Member
  • ***
  • Posts: 222
Re: powder selection
« Reply #7 on: March 26, 2012, 01:54:19 PM »
Quote
each gun has its' own like and dislikes; and you'll never know until you try different loads in your gun and measure some groups.

Ed Zachery!   ;D     I have one .40 caliber rifle that will shoot far more accurately  with ffg Swiss than any other powder I've shot in it.  Most people will tell you not to bother trying that. 

Fred_Dwyer

  • Guest
Re: powder selection
« Reply #8 on: March 26, 2012, 03:45:49 PM »
Here's a whole mess of reading about black powder. Put on a pot of coffee  ;D
It doesn't specifically answer the question; it will show that "it isn't as simple as that."

http://www.laflinandrand.com/page3.htm

I found part 9 interesting because it discusses fouling, lubes, and ease of loading.

The other DWS

  • Guest
Re: powder selection
« Reply #9 on: March 26, 2012, 03:56:53 PM »
Thank you very much for that link.  I have a few more days before I have to get back on the road, so I think I'll have a lazy one, and a couple post of coffee, exploring it.

northmn

  • Guest
Re: powder selection
« Reply #10 on: March 26, 2012, 07:57:35 PM »
I quit using 4f in my 25 because it was too self priming.  I had to place a toothpick in the touch hole when loading it.  My 25 uses a smaller touch hole even.  As to fouling, it works best with Grafs 3f as the fouling is softer than with GOEX.  Some claim Swiss is also softer, but Grafs works for my uses and is half the price.  Those shooting at Rondy's and range shooting find that the liquid solvent type lubes also keep fouling down.  For longer periods of carry I use a grease lube as it retains its integrity and may also help protect the barrel.  I have often quick cleaned my barrel after a shot in the woods before reloading.  One problem with small bores and fouling is that they generally like a higher powder to ball weight ratio.  My 25 likes 20 grains of 3f, many 32 shooters like 30 grains.  In a 45 that would translate to about to a 100 grain powder charge.  The ball mass to bore diameter is also less in a small bore which can also affect efficeincy and cause a little more fouling.

DP

The other DWS

  • Guest
Re: powder selection
« Reply #11 on: March 26, 2012, 09:09:09 PM »
As I read the "Mad-Monk Reports"  I am realizing that its a whole lot more complexicated than simply the powder selection (though brands, grain sizes and charge weight/bore size are interrelated factors).  I have shot ML arms off and on for years, but my approach has been pretty casual.  Largely thanks to this site and its community I am developing a more advanced level of interest---and, I hope, accomplishment.

I read here on the site how some have need to clean/wipe every few shots,  others shoot 50 or 60 of more with no problems  (larger bores I imagine)  I'm operating on the assumption that "smaller is finickier" and that this new to me .29 small bore will be a whole new adventure
 
It appears that temperature and to some extent relative humidity have a big effect on fouling, its physical characteristics, and the ease of reloading without needing constant recleaning.

  I suspect that the cooler moister nature of the Pacific Northwest would make muzzleloading a lot easier than other parts of the country.  hot dry summers here may prove to be a bit challenging.

northmn

  • Guest
Re: powder selection
« Reply #12 on: March 27, 2012, 08:30:00 PM »
How much you wipe between shots depends a great deal on lube and patch/ball thickness.  A tighter ball/patch combo fouls less.  Also use of solvent type lubes like Hoppes #9+ as an example also helps to clean when you load.   I use the grease as a hunting load as the wet lubes dry out over time and may not work if the rifle is carried a couple of hours.  Also, during deer season the rifle may be left loaded for more than one day.  Humidity and temp also play a part but to me lube and fit are the biggest ones.  If you insist on loading without a short starter (don't know if you do or not just as an example) you will get more fouling.

DP

FRJ

  • Guest
Re: powder selection
« Reply #13 on: May 11, 2012, 06:56:27 PM »
In the new barrel I just bought for my GPR I have found that 2f in relatively small charges(60 gr) in  54 caliber leave virtually no fouling and that cleaning is more of drying out the bore than cleaning out the fouling. My old barrel that was very badly pitted from the use of Pyrodex, took forever to clean and didn't shoot anything really well. Even when I go to 90gr 2F there is little fouling and it can be shot far more times than I care to shoot it without cleaning. Also part of it may be due to my use of a very tight patch and ball fit in the barrel. I get great groups, better than I thought I could shoot anymore, with 2f and havent even tried 3F as I doubt I could do any better with it. FRJ

Daryl

  • Guest
Re: powder selection
« Reply #14 on: May 11, 2012, 07:18:42 PM »
Depending on lubes, I use between 55gr. 2F or 3F to 65gr. 3F or 75gr. 2F in my .40 - NO fouling problems or differences noted with any load.

In the .32, I use 35gr. 3f for all ranges initially with a .311" ball and now with a .320" ball (.319"Lee mould) The .311" shot just fine, with no fouling problems up to 40gr., but 35 was more accurate at 50yards. I could not get this barrel under 1" at that range, hence my purchase of a .319" mould. I have not tested it yet, except for ball fit with the patch I'm using- .019" to .023". Both load and fit just fine, no cutting. I haven't bench tested it yet.

In the .45, I use between 65gr. 3F with water based to 75gr. 3F and 85gr. of 2F with oil - same deal with no fouling changes.

In my 24" .577 Musketoon (.574" bore) - a mere 75gr. of 2F, gives a .562" ball a velocity of 1,308fps.  I now use 85gr. 2f as it's more accurate, especially at 100yards - 3" for 5 shot groups, I did not chrono it yet - battery failure the day of testing)  No fouling problems.

In my .58 Kodiak,  100gr. shoots together at 50yards, crossing 1" at 100yards - 3" groups - with both barrels counting. I use a Lyman .570" mould that casts .574" - NICE! they also shoot well in the Musketoon with a .020" patch - with only .003" deep rifling at the muzzle - yeah - short starter is needed or a very calused thumb that can be hit with a starter. ;)

My .69 uses 2 loads, both quite efficient - close range plinking with 82gr. 2F gives 1,200fps and 165gr. gives 1,550fps - no fouling with either noted. both using .684" ball and .030" patch, but the lighter load can use a .0225" patch if I have some cut. The heavier load needs the thicker patch to maintain accuracy at long range - to 200yards - 2 1/2" last year in testing- 5 shots. So - please don't tell me that's too much powder - at that range, it's needed. Oh- no fouling problems.

In none of these guns do I EVER wipe during a day's shooting. It just plain isn't needed.

I should note here the reason I have 2F loads for both the .40 and .45, is just in case I run out of 3F, I know what powder charge of 2F gives the same accuracy as 3F - in both rifles, it's 10gr. more.

I do not use 3F in my .58's as with DPeck, I get better, more consistant results with 2F.  If I had a .50, I would use 2f solely just for that reason.

« Last Edit: May 11, 2012, 07:22:37 PM by Daryl »

Offline smylee grouch

  • Hero Member
  • *****
  • Posts: 7629
Re: powder selection
« Reply #15 on: May 11, 2012, 07:36:33 PM »
There are those who claim the optimum load should burn right to the end of the muzzle but I question if that is posible shooting black powder in anything except an extremly short barrel. I am sure someone will corect me if wrong but the way black powder flashes insted of burns I have questions. Anyone here know the explanation?      Smylee

Daryl

  • Guest
Re: powder selection
« Reply #16 on: May 11, 2012, 11:05:38 PM »
Smylee - do they mean that the powder gasses are stopped expanding at the muzzle, indeed where the velocity will actually be reduced if the barrel was longer - or that the entire charge is consumed right at the muzzle, without any time given for those gasses produced by the last kernals of powder burning, to expand and promote velocity increase?

Do they mean to where there is a reduction in the rate of increased speed with the same increase in powder charge?  That is easily proved when using a chronograph, but those results can be changed through the use of a looser or tighter patch and a change also in the lube used.

My own tests show a reduction in accuracy but an increase in speed with the same powder charge when switching from a water based to an oil based lube - same patch for all testing.  There was also a greater variation in velocites, shot to shot which tends to show the oil produced more variance in pressure which translated to the velocity of the balls. With increased charges, the oil loads became more stable in velocity spreads, but never to the level of the water based lubes before I stopped the test due to what I felt were extremely high loads.
  
In that test, the water based lube was my own spit and the oil was bear's oil or grease. At no time did the oil shoot with the same accuracy as spit.

Tests done by others 'in the know' have stated that all black power, no matter the granulation burns very near the breech with some slight variation in length of barrel used when using black powder, unlike a smokeless powder which peaks pressure further up the bore.  The short pistol length minnie guns, like the .58 with 12" barrel effectively expanded the minnie, even though it had a short barrel- in fact this proved to the scientists of the time that even the Civil War powder burned completely close to the breech unlike with the very slow burning powders used in large magnum cases, a mere 14" is 'further' up the bore where they peak pressure.  Even the fast burning modern powders will not effectively expand those minnie or flat based bullets tha tblack powder seems to so do easily. The rapidly expanding gasses from the burning powders shock the bullet into obturating into the grooves.

Thus it is only the continually expanding & burning gasses which produce the increased velocities with greater barrel length, not previously unburnt powder burning close to the muzzle. The more expanding gasses, the higher the speed.  Efficiency also comes into this equation, as noted in the second paragraph. It is the flaming solides we see exiting the muzzles of the guns, not unburnt powder.  Even a 20gr. charge in my .32's 38" barrel ejects 'sparks' out the muzzle, as does Hatchet Jack's 20 bore with a mere 65gr. of 2F. We see this every time we take a photo. It is not unburnt powder, but burning red hot solid waste - some of the 57% of the original charge's waste that occurs every shot.

What do you need? What does the gun say to use to give the best accuracy. What is needed, within acceptable accuracy that gives the desired trajectory for shooting game?

Much of this stuff I'd probably not thought of if I hadn't quit the morphine pain meds last Sunday. Been a rough week but with improved clarity & pain - neither are surprising.
Im my opinion, of course.
HA!
« Last Edit: May 11, 2012, 11:14:41 PM by Daryl »

Offline Long Ears

  • Hero Member
  • *****
  • Posts: 714
Re: powder selection
« Reply #17 on: May 12, 2012, 05:22:48 AM »
Daryl, sorry I just hope the morphine isn't needed to shoot those loads you quoted. Good luck, Bob

Offline smylee grouch

  • Hero Member
  • *****
  • Posts: 7629
Re: powder selection
« Reply #18 on: May 12, 2012, 05:26:40 AM »
Daryl: I have heard many so called blackpowder expert shooter talk about the best load. I am not an expert even though I have been shooting Muzzle Loaders since the 1960s. There are those who say shoot enough powder but not enough so that you can find unburned powder on the snow in front of your gun. I question being able to find unburned powder out there. My belief is that the charge is consumed in an average length barrel long befor it gets to the muzzle. I have read others opinions on this from people who know one heck of alot more than I do that coinside with my own. Old wives tales insted of science. Good luck with your meds and best wishes.   Smylee

Daryl

  • Guest
Re: powder selection
« Reply #19 on: May 12, 2012, 06:12:43 PM »
TKs guys - doing better, every day.  One must be aware that with 57% of the powder charge being solid waste after it's fired, the black specs on the snow or white sheet as some have suggested might not be powder at all.  I challenge someone who thinks it is unburnt, to gather a bunch of it up and see if it goes whooooosh!  I'd lay odds it won't.