Powder Burn Rate Charts

[Deleted]

I have a couple of Powder burn rate charts where 180 powders are listed form fastest to slowest rate of burn.
Is there Powder Burn Chart out there that gives a numerical rate of burn to each one of these powders?

ie. H4198 vs. Retumbo

Numerically, how much faster does H4198 burn than Retumbo?

[Dave W]

4198 is all most twice as fast as retumbo and probably not the wisest choice for a .416.

[deadeye]

i agree w/ davew

here is a more reliable burn chart imo- h4198-#139///retumbo- #253

www.reloadersnest.com/burnrates.asp

[Deleted]

Is there a chart out there that has a numerical value attached to their position on that chart to compare one powder's rate of burn to another's.

[willbird]

Powders will swap places depending on the ctg sometimes.

[edge]

The Powley computer is designed for IMR powders since they all have the same energy per grain with different burn rates.

This may not help, but these are the numbers that used to be published by IMR and used for some Powley computer versions.

SR4759 210
IMR-4227 180
IMR-4198 160
IMR-3031 135
IMR-4064 120
IMR-4895 115
IMR-4320 110
IMR-4350 100
IMR-4831 95

If you look at a burn rate chart where these powders are and compare to the powder you are looking to use it may or may not help.

edge.

[willbird]

kwk.us/powley.html

Above is the link for an online powley computer, but what is the VMD for water??

[willbird]

Found it at Cast Boolits

Water has a VMD of 0.0648 cc.

So if we seated a bullet on top of 120 grains of Retumbo, and pulled the breech plug, and refilled the whole powder with water it would be 133.52 grains of water.

[willbird]

The Powley ideal is 80% loading density...so in that 133 grain of water "ctg" it tells me 94.2 grains of 4350 or 4831 and a 400 grain bullet would give me 2370 fps in a 26" barrel.

Again I think powley tries for a 80% loading density. I think it is telling me this load would be 80%. It says pressure would be 43,400 cup

[willbird]

Here is some info on relative quickness from that powley webpage

Relative quickness data are based on laboratory tests instead of on gun firings, and serve as a general guide for the expected performance in cartridges, but it is found that powders which are placed fairly close together in the relative quickness range may change their relative positions if ranked according to their performance in actual gun firings. This is particularly true of IMR 4064, IMR 4895 and IMR 4320, which rank in that order according to relative quickness, from "fastest" to "slowest." In actual firing, however, IMR 4064 is often found to allow higher charge weights, and produce higher velocities at acceptable pressure, than do either IMR 4895 or IMR 4320, both of which rank lower ("slower") on the relative quickness scale. For that reason, it is impossible to say with certainty which of the powders in this group ... will be found most suitable... The same is occasionally true of IMR 4350 and IMR 4831... The choice among powders within these groupings cannot be reliably predicted by calculation...

[Deleted]

Holy cow! Anybody try to buy powder lately?
Everyone is sold out of h4895 and h4350.

[Richard]

I was looking at bullets for my 9mm and .380 on a number of good sites..........?? "0" in stock! Same with ammo for those guns! With the exception of some high priced self defense loads, everyone is showing "0" in stock
Richard

[willbird]

Jan 12, 2013 20:25:36 GMT -5 Richard said:

I was looking at bullets for my 9mm and .380 on a number of good sites..........?? "0" in stock! Same with ammo for those guns! With the exception of some high priced self defense loads, everyone is showing "0" in stock
Richard

feels like 2008 all over again

[Savage Shooter]

Jan 12, 2013 20:25:36 GMT -5 Richard said:

I was looking at bullets for my 9mm and .380 on a number of good sites..........?? "0" in stock! Same with ammo for those guns! With the exception of some high priced self defense loads, everyone is showing "0" in stock
Richard

Search Here:::::: ammoseek.com/

If its out there it can be found here.

[edge]

Jan 12, 2013 14:52:43 GMT -5 willbird said:

The Powley ideal is 80% loading density...so in that 133 grain of water "ctg" it tells me 94.2 grains of 4350 or 4831 and a 400 grain bullet would give me 2370 fps in a 26" barrel.

Again I think powley tries for a 80% loading density. I think it is telling me this load would be 80%. It says pressure would be 43,400 cup

I am not sure if I understand your interpretation of Powley.

IMO, Powley wants a full case AND to achieve about 45kspi tells you the IMR powder to use based on your inputs. PERIOD.
IIRC IMR powders have an average of 0.86 weight per grain relative to H2O.

Here is the graphical version of Powley:


It MUST be understood that Powley was designed around IMR powders which are ONLY single based and have the same energy per grain. To substitute a powder with any nitroglycerin content can raise pressures catastrophically!

edge.

PS You tell Powley how much powder and Powley TELLS YOU THE POWDER to use...PERIOD!

PPS
Now in a ML you could use it backward. If you want IMR4198 WITH a 0.458 bore WITH a 300 grain bullet you can calculate how much powder.

I made a spreadsheet many years ago but do not put it out because of the constraints of Powley and the importance of choosing the powder!

[edge]

My spreadsheet attempting to use 4198 powder with a 300 grain bullet.

Scenario #1 I guess I want 80 grains so I input Powder #1 IMR4198:



YOU WILL SEE THAT THE CORRECT POWDER IS ON LINE E16
The correct powder speed would have a speed rating of 133
Next you look at the IMR speed rating and find the closest powder is IMR 3031 with a speed rating of 135.

THE VELOCITY AND PRESSURE ARE ONLY APPLICABLE FOR AN IMR POWDER OF 133!!
IF YOU USE 80 GRAINS OF IMR4198 THE PRESSURE AND VELOCITY WILL NOT MATCH THIS SPREADSHEET!!!

So I keep lowering the grains of powder until the IMR selector is close to IMR 4198 which I find is around 53 grains:



Now the good thing about Powley is that it tends to be about 15% high in its calculations for large bore rifles, which means that instead of the 44kpsi predicted it will probably be closer to 38kpsi.

Powley was a way for wildcat shooters to get a starting load that would almost always be safe.

edge.

[Deleted]

WOW!
That's some great info edge.
Thanks!

[willbird]

Edge I started playing with dads powley slide rules when I was about 12.... But I m still learning about how they worked....the 80% loading density was something dad told me.....maybe it was the MINIMUM ? I did find this in the notes from that website.


The calculations are simple. The volume under the bullet, as measured in gn of water, is multiplied by 0.86 (or by 0.80, for 4198 and faster powders) to give a charge which will nearly fill the case. This calculation is related to the average density of the IMR powders. A separate, empirical equation is then used to determine which IMR powder will produce a peak pressure of about 44,000 CUP using this load. Finally, the equation considered by Faber is used to estimate the muzzle velocity.

[willbird]

And I guess I am puzzled a little bit then, because when I back figure the 94.2 grain load of 4350/4831 in the 133 gn water ctg, it comes back to 78% loading density, of course the ctg is probably so large that an IMR slower than 4831 would be required to fill the fictional case ??

[willbird]

Now I am more puzzled :-), I scaled the fictional case back to hold 94.2 grains of 4831, and powley tells me to use 69 grains, again less than 100% loading density. 74% to be exact. I did not change the case length or round length of the fictional case, just the capacity...it just got fictionally thicker case walls.

133 water grain case
94.2 grains of 4350 or 4831 and a 400 grain bullet would give me 2370 fps in a 26" barrel. 78% loading density
105 water grain case
69.6 grains of 4350/4831 2154 fps 74% loading density

Playing with all different case capacities and a 400 grain .416 bullet I cannot coax the online Powley to give me anything larger than 86% loading density with 4350/4831

[edge]

Jan 13, 2013 10:26:12 GMT -5 willbird said:

SNIP.

Playing with all different case capacities and a 400 grain .416 bullet I cannot coax the online Powley to give me anything larger than 86% loading density with 4350/4831

100% full case of 4198 is only 0.82%
Looking at my graphical version you would see that WW 680, which I assume is a ball powder, would give a density of .99%

The bulkier the powder the lower the density.

IIRC ball powders were originally reformulated from scrap/overstock powders.

edge.

[willbird]

Wait a minute here, now I see something, I found an excel version of powley online, and I got it to agree with the website....BUT there was something I was not understanding, these versions are working with a case FULL of water, NOT the capacity of a case with bullet seated.

The old powley slide rule as I recalled you had to measure how much water the case held with bullet seated.

[willbird]

To get a powder chamber of 133 water grains I had to pick a full case capacity of 157 grains.

THEN it tells me I need 114.0 grains of powder number 88(slower than 4831, and I would get 2523.4 fps.

All of this using a fictional construct of a case drawn in autocad which would have a .416 internal bore from case mouth to solid web.

[willbird]

Here is what the excel sheet I found looks like opened up, you can see the data I entered and the results. I did not edit where it says "308 winchestor" from how it was when downloaded.