Powder "Speed" for cast.

[mdi]

I have been casting and shooting lead boolits for several years (Mebbe 14-16), and have always used load data from a Lyman Manual and have worked up clean loads (using mostly fit and alloy hardness), usually with a specific cartridge, one at a time. I recently bought some powder and as I was re-checking load data I realized I have not researched "optimum powder burn speed" for cast boolits, if such a theory exists. So, which is better for cast boolits, fast powder for caliber or slow for caliber? (like is W231 better for cast bullets in .44 Magnum than 2400?). Velocities, charge volume, etc., aside, just burn speed...

Thanks

[Tatume]

There's no simple answer to your question. For example, very slow powders will often work wonders in rifle cartridges, whereas nobody would dispute the success people have had with Bullseye in pistol and revolver cartridges.

Sometimes the middle of the road works well too. H110 and W296 often work well with heavy cast bullets, but sometimes not with standard weights. My experience with 240 grain cast bullets in the 44 Rem Mag is 2400 is optimal for full-power, and I can't get W296 or H110 to group worth beans.

So, like I said, there is no short answer.

[OS OK]

One example…I've worked up loads with Herco, a slower burning powder of the pistol types, tried to push a .45 ACP 200g. L-RNFP & L-SWC (both PC'd) at 950 FPS. It would do that but with primers getting on the hi pressure side and they did not group tight. It would push at 900 FPS with no indications of hi pressure but its starting pressure in the chamber does not expand the cases properly to seal the chamber and you get smokey stained cases as a result. At this speed they grouped better/tighter.
I think this Herco at the hi end of pressure is peaking in pressure too close to the end of my Commanders 4.25" barrel and the boolit is exiting with too much excess pressure behind it and that affects the grouping aspect.
I'm no engineer in powder physics or chemistry but I do pay close attention to the results and try to reason them out as best as I can with the tools we currently have to use.
Overall and bottom line now for me is to read a powder manual and understand what the manufacturer suggest for a particular powers use and use that recommendation as pretty much gospel to start your own observations.

Good luck tooya! charlie

Edit: http://castboolits.gunloads.com/showthread.php?297867-The-Wizardry-of-Propulsion
I posted this read some time ago and it will definitely give you perspective regarding powder burn rate in a rifle powder, nothing to my knowledge has yet been published regarding pistol powder…dang it!

[44man]

Fast powders have instant pressure rises and can destroy a boolit even before it engages rifling.
I found 231 and Unique in the .44 need jacketed or cast at 28 to 30 BHN. With 296 I use 22 BHN, water dropped WW's.
Back in my IHMSA days I found 296 with a 240 gr Hornady was the best. !/2" groups at 50 meters and many 40's shot. Won Ohio State with 79 out of 80, last ram I missed from a shake.
I LOVE 296 and use it in everything from the .44, .475, 454, and .500's. It works for cast like no other. You need to load right of course, no downloads under starting loads.
Shoot soft wad cutters from a .38 with Bullseye and wish you had a magic lead erasure or magnet.
Bullseye in a .44? get real.
While 2400 was good for the time and I used a lot of it, 296 exceeds it with both velocity and accuracy.

[centershot]

There are way too many variables to give a simple answer. i have had excellent results with Bullseye & 231 in light target loads, both in handguns & long guns. Unique & Blue Dot have worked well for "mid-range" loads in pistols. For high performance handgun loads I have found nothing better than 296/H-110. These powders span the "fast-to-slow" range of pistol powders for most calibers. Just depends on the application. In rifles, with cast boolits, anything from Bullseye to H-4831 has been good to me. As I said, it's the application; which cartridge, which boolit weight, how hard, what o.d., how fast????

[runfiverun]

well.
ummm m.
yeah.
I done a work up using about 8-9 powders from clay's through 2400 in both my 44 and 45 colt.
they all shot well, some went faster.
they all made holes in the paper, the holes were about the same distance apart.
I did have to adjust the rear sight for elevation.

the question is well what are your planned uses for the round?
300gr boolits with 25grs of powder is pretty inefficient for 25yd groups, not too bad a choice for shooting a Moose at 75yds though.

[mdi]

My question was in regards to all around performance and especially leading. I have worked up loads in my handgun cartridges with powders from Bullseye to WC 820 and H110. I have read that some casters prefer a powder for a cast bullet cartridge, depending on it's burn speed. Not considering handgun powders in rifle cartridges, like my Unique in a 303 British cast bullet loads, but normal powders used in handguns, like my explanation of W231 to 2400 in .44 Magnum. Which burn speed powder is best for cast bullets?

As I said in my OP I have worked up loads with a wide range of powders in all my hand guns cartridges and rifle cartridges. Accuracy doesn't seem to have a lot with burn speed (I've got some accurate loads with both W231 and WC 820 in my .44s). Just wondering if cast bullets work better with fast for caliber powders, or slow for caliber powders...

[runfiverun]

well what works the best for me is to basically find that 3/4 load.
the powder that is about 3/4's the way to the slowest and I run it about 3/4 throttle.
8.5-9 grs of unique is my go to load in the 41/44/45 colt.
it's enough without being too much.
I shoot it in my revolvers/lever guns with rffp or swc type boolits and under weights from 165 up to 270 grs.

going to the slightly smaller 44 special and 45 acp I step the powder down a notch in burn rate. [faster] and treat the two the same as far as velocity goes.

when I get down to the 9m and 38 class of cases I'm in the red-dot and bulls-eye burn rates for the bulk of my loads.

I might wander off track for each round here and there but it's generally for a specific purpose type load.

[MT Chambers]

For every shooter favoring a faster powder for best accuracy, there will be others that favor a slower powder.

[JonB_in_Glencoe]

the short story for alloy pressure theory.
Ideally you want the charge high enough, to just to start to obturate the bullet.
faster burning powders spike the pressure quicker and are better for lighter loads using a softer alloy
Slower burning powders spike the pressure slower and are better for pushing heavy bullets faster using a harder alloy.

Then if you read between the lines, you can tailor almost any load for a certain weight bullet, using a certain alloy, for a certain caliber. There is probably a fancy math formula for this ? or maybe not.

[40Super]

I have somewhere around 20-23 powders here for pistols alone , I can make a good load (accuracy, decent speed, and no leading) out of each of them for most calibers it's practical to use them in . General I like mid to slower for the caliber , mostly filled case at 80% speed.

[Shiloh]

Bullseye and Unique have served me well for pistol.
10 gr. Bullseye works magic in a .40-65 with a 385 gr. boolit. 20 grains 4227, slow pistol powder becomes fast rifle powder behind a 314299.

Shiloh

[mdi]

Thanks JonB. That's as close to an answer so far. My question was just wondering how powder "quickness" affected cast bullets. I too have worked up good loads for my handguns using all the "normal" powders from the fastest (Bullseye) to the slowest (H110/W296) under cast bullets...

[murf205]

Well, everyone has his or her personal favorite, but for me it's 2400 for the reason that you can slow a load down if need be without ignition problems. I load 16.5 grs. behind a 255 gr boolit in my 44's for 1050fps in a 4" 629 and 1225 in a 9" Super Redhawk. I agree that 296/H110 is a powerhouse especially with heavier boolits, but it does not like to be loaded down. Also, Skeeter Skelton's old load of 7.5 grs of Unique in a 44 spl is still hard to beat. I'd hate to have to get by without either of these 2 powders. I think boolit fit is a lot more important than powder speed. My 2cents worth.

[40Super]

Definitely fit is #1 , by a long shot . When I first started I tried all other common things to get rid of leading , part of the reason I have so many powders. Some barrels seemed ok others nothing would stop it . Once I picked up a bunch of lead sinkers and pushed them through all my barrels , then things were made clearer. I was buying bullets then and most just had standard sizes, however many of my barrels were at that very size or .001"+ bigger . I bought my first molds and sizers for making sure all boolits were .001"-.0015" over each barrel size ,that meant a few barrels had their own molds to get big enough. My leading just disappeared . Now to an extent hardness and powder are just tweeking options .

[mdi]

Well, I guess the consensus is there ain't no benefit to using a fast or a slow powder for cast boolits...

[gwpercle]

With the lack of availability , handgun powders are in extremely short supply around here , I've resorted to the " use whatever you can get " method.
If I can find data , I buy it and use it.
In handguns I've been forced to use, at one time or another , Alcan #5 , Unique , 700X , Bullseye , and Red Dot ....... and they all have worked just fine .
Gary

[fredj338]

Well, I guess the consensus is there ain't no benefit to using a fast or a slow powder for cast boolits...

It just depends on what you are trying to do. For light target loads, you are likely to get better results with some form of faster powder. For medium vel loads, pushing faster powders seems to be problematic for me accuracy wise. So medium burners, like Unique or WSF will work well there. For higher vel, nothing but slower powders is really safe. I've often felt if a handgun wouldn't shoot lead bullets with either Unique or 2400, it probably won't shoot a lead bullet well with anything. There are some newer powders, like BE-86, which may change things but that is where I am at.

[mdi]

I fully understand powder burn speed for various needs; faster for light target loads, and slow for magnum type loads. I was just wanting to know, from member' experience if burn speed was a consideration for cast bullets...

Sometimes it's really hard to get a thought across on a forum. :-(