4198 vs. 4759

[Marlin Junky]

Given we are dealing with typical starting loads, how much (in terms of percent) does one need to increase the charge weight of IMR 4198 over a given amount of 4759 in order to match the velocity generated by the latter. Let's say the cartridge is the .358 Winchester or the .35 Whelen and the boolit weighs 250 grains.

MJ

[charger 1]

Let me first say I really dont like getting into this VS that threads, things like ballistics,cartridges, powders must be stand alone. I'm not trying to be snotty, but heres why. In my savage muzzleloader it takes 68 grains of H4198 to do the same job as 43 grains of 4759...Hold on, is that relevant?In both cases the saboted projectile seats fully to eliminate air. Lets say 30 of 4759 does what 40 of 4198 does with projectile X in a 45/70. Does that mean it holds the same ratio in say a 358 with the different volume, neck etc....I think yer playing with fire...

Thats my story and I'm stickin to it

[S.R.Custom]

I've made these comparisons and extrapolations many times when there has been the absence of appropriate load data, and it seems to work quite well...

MJ, I'd look at my Sierra manual (or similar-- the more sources the better) and make a list of similar pressure cartridges (30-06, .308, .300 Savage, etc) that list both powders for the cartridge, and compare the amounts in terms of the percentages. Compare enough samples until you begin to see a clear correlation.

Just be certain of your math. [smilie=1:

[Shiloh]

4759 is a faster burning powder than 4198. Projectile velocities can be higher with a lighter powder charge due to higher pressures. One wonders, are the pressures curves a linear type affair or some sort of exponential equation in comparing one powder charge/velocity to another.

In other words, I'm not sure you can safely depend on percentages alone in comparing one powder charge to another. Wouldn't it vary from one application to another? Wouldn't it also vary any time you changed one of the variables like primer, projectile, casing or firearm??

I'm not sure I would want to depend on percentages alone. This sound like some sort of testing done by ballistic/physics engineers.

Shiloh

[Char-Gar]

Like others, I have looked at loading manuals and have done some extrapolations from one powder to another. But, this is a do it yourself project that might get you into trouble if you put your foot in the wrong place.

Powders are very different in how the act in the individual case and the type of fixed formula you are looking for is not available because of the almost infinite number of variables.

I doubt if you will find anybody on this board who will make so bold as to give you want you ask. To do so would not be in your best interest or responsible.

[S.R.Custom]

... One wonders, are the pressures curves a linear type affair....

They most assuredly are not. (Which, I suppose, is why they're called "curves." [smilie=1: ) But in terms of safety, we're only concerned about peak pressure. The nature of the curve itself will determine things like ES, SD, and ultimately--accuracy.


I'm not sure you can safely depend on percentages alone in comparing one powder charge to another.

Absolutely true. You have to compare charge weights to case volumes to caliber size to bullet weights.... Hence my suggestion to compare "similar" cartridges. You do NOT want to make a comparison between, say, a .444 marlin and a .243.

[Marlin Junky]

I've made these comparisons and extrapolations many times when there has been the absence of appropriate load data, and it seems to work quite well...

MJ, I'd look at my Sierra manual (or similar-- the more sources the better) and make a list of similar pressure cartridges (30-06, .308, .300 Savage, etc) that list both powders for the cartridge, and compare the amounts in terms of the percentages. Compare enough samples until you begin to see a clear correlation.

Just be certain of your math. [smilie=1:

SuperMag,

I've already done that with the data available to me (mostly my own data) and I'm getting between 25% and 40% more 4198 needed to equal the velocity generated by 4759 so I was wondering if others have actually done the tests with the .358 or .35Whelen and 250 (or better) grain boolits. Basically the reason I'm doing this is because I'm running out of 4759 and I want to equal or approximate the velocity generated by the 4759 with a somewhat slower powder (IMR 4198) to see if I get better accuracy with less pressure. I'm planning to load long boolits into the short necked .358 cases and my COL needs to be 2.4" because of limited chamber throat; therefore, I've got one driving band and the GC in shoulder/body area. I'm just trying to get good results at 1700 fps or a bit faster, I'm not trying to break any speed records... my original post did open with, "Given we are dealing with typical starting loads... ".

MJ

P.S. I'm going to split the difference and go for a third more IMR 4198.

[w30wcf]

MJ,

Lyman Handbook 47th Edition.......

.35 Whelen
358009 - 280 grs. #2 alloy
25.5 grs. 4759 - 1,654 f.p.s. - 25,300 C.U.P.
30.0 grs. 4198 - 1,753 f.p.s. - 23,500 C.U.P.


w30wcf

[Marlin Junky]

Thank you John,

Did Lyman do the same for the .358?

MJ

[405]

Lyman 48th Edition

358 Win
#2 alloy
204 gr 358315
4759 19 gr. 1601 fps 21700 CUP
4198 25 gr. 1643 fps 16500 CUP

I think I'd invest in as many manuals new or used as I could afford :coffee:

[Marlin Junky]

Lyman 48th Edition

358 Win
#2 alloy
204 gr 358315
4759 19 gr. 1601 fps 21700 CUP
4198 25 gr. 1643 fps 16500 CUP

I think I'd invest in as many manuals new or used as I could afford :coffee:

Thank you 405. Even though that boolit is too light, I appreciate the data. Are you guys quoting from Lyman's cast bullet manuals or their reloading manuals? I've got one of their reloading manuals that is a 40-something edition but that data is not contained in it.

MJ

[405]

The Lyman Cast Bullet Handbook lists the following bullet weights for the 358 Win:150, 206, 247. The only powders for those bullets listed are the faster pistol and cast bullet types.

The Lyman 48th Edition Reloaders Handbook lists the following jacketed bullet weights for the 358 Win: 180, 200, 220, 250. The cast weights listed are: 195, 204. The powders listed are the normal rifle powders, including 4198 and 4759.

The Lyman Cast Bullet Handbook lists no pressures for the 358 Win cast loadings.

The Lyman 48th edition lists pressures in CUP for all loads in the 358 Win.

I would not try to extrapolate pressure data from one powder to the next. Even extrapolating pressures within the same powder is not recommended because the relationships are complex curvilinear in nature and tend to become very "squirrely" at the high and low extremes!
If the internal ballistics of firearms was fully understood then the ballistics labs that do the pressure tests would not be testing all the loads!

[S.R.Custom]

Ultimately, MJ, you may not care what the answer is, if your experience is anything like mine; I've never been able to get 4198 to group worth a damn in bottleneck cartridges. The smaller the bottleneck, the worse it behaves. Works great in straight wall cases, tho.

That said, I went through some of my data (starting numbers are indicated below). I included Reloder #7 where I found it because it appears just above 4198 on the Burn rate charts:

Speer-- 250 gr-- 33.0 Reloder #7 (for the .356 Winchester)
Speer-- 250 gr-- 33.0 Reloder #7 (for the .358 Winchester)
IMR-- 250 gr-- 32.0 IMR4198 (for the .356 Winchester)
Nosler-- 225 gr-- 32.5 Reloder #7 (.358 Winchester)
Sierra-- 225 gr-- 35.2 IMR4198 (.358 Winchester)
Alliant-- 250 gr-- 34.5 34.5 Reloder #7 (.358 Winchester)

Lyman Lead-- 250 gr GC-- 22.0 4198 @ 1465fps
--(they show 31.0 as a max, 358 Win))
Lyman Lead-- 250 gr GC-- 21.0 4759 @ 1710 fps
--(they show 30.0 as a Max, 358 Winchester)

Saved the best two for last. :mrgreen:

[Marlin Junky]

Lyman Lead-- 250 gr GC-- 22.0 4198 @ 1465fps
--(they show 31.0 as a max, 358 Win))
Lyman Lead-- 250 gr GC-- 21.0 4759 @ 1710 fps
--(they show 30.0 as a Max, 358 Winchester)


SuperMag,

Thank you! Before your last post, I had decided 21 grains of 4759 and 24 to 25 grains of IMR 4198 would do about 1700 fps based on my experience with 4759 in the .35 Whelen (the .358 has about 80 to 81% the volume of the Whelen). Now I am much more confident and will try 25 and 26 grains of IMR 4198 insted of 24 and 25 during my next range session.

I too prefer Re7 over IMR 4198 but I'd like to use what I have in house and I need a little airspace in the case for a grain of Dacron to protect the base and keep the Javelina out of the powder. Otherwise, I'd probably try to use up some old 3031.

Thanks again for looking up that data.
MJ

P.S. I got 'em loaded up last night but decided on a 1/4 sheet of 1-ply TP instead of a grain of Dacron, the latter of which proved to be too much filler. I did place 0.6 grain of Dacron in two of the rounds loaded with 25.0 grains of 4198 to see if their velocity ends up more than one or two sigma from x-bar.

[eagle-eye]

Dear mr. Powder comparison guy.

Powder is measured in grains weight and not volume for smokeless powders.

From hornady reloaders manual.

358 winchester
h4198 max charge of 39.6 grns
hornady 250 grn bullet #3525
-yields a 2300 fps load

set aside all of the nonsense and go buy a reloading manual and follow the instructions before you or someone you hand one of your percentage loads to gets hurt.

[44man]

Strange things can happen with 4759. I use it in my 45-70 revolver and it works to perfection with the right amount.
I had a boolit to work up with and found reducing the powder a small amount over what I normally use was giving me poor ignition. I use Dacron over the powder.
I wanted a mouse load for the .50 Alaskan so I took the charges from comparable .50-110 from the Lyman manual. Only one lit off and it felt like a .22. I need more powder but there is such a lack of loading info, it is hard to guess at a load and I will not do it. Hodgdon doesn't have any info with 4759 in the Alaskan. The case is so large, where do you start and stop?