Powder Burn Rate Comparison Charts

[franzfmdavis]

I have seen a lot of questions on the forum about powder comparisons and thought it might be useful to share these attached charts for those who may not have seen them yet:

 

[grand veneur]

The internet is full of diagrams like this and each one shows something different. They only serve to divide the powders into a range in terms of their burning rate. You cannot do anything with it for reloading cartridges. You can maybe do something with the relative velocity and the relative pressure of the various powders, so far as those are stated, but it remains very imprecise when it comes to single or double base powders that you cannot compare. Ultimately, in order to reload safely, you need loading data from well-known manuals and a lot of personal experience.

 

[Ontario Hunter]

Interesting. I'd like to find a way to make it relevant. Today at the range I was trying out (again) some trial loads of 307 gr Hammer 404J bullets using start load data for 300 gr bullets at 84 gr IMR 4895 powder. Holding onto that rifle as hard as I could and it still kissed my eyebrow three times. The weird thing is I can shoot 400 gr Barnes X loaded with Accurate 4350 no problem at all. That's 93 gr difference in bullet weights! The Hammer bullets SHOULD have significant LESS recoil, not more. Just now checking the brass I see one primer is flattened.

Something's wrong. Better call Hammer tomorrow. IMR 4895 must have some serious "burn rate" punch per grain.

 

[375 Ruger Fan]

Another useful chart is the temp stability chart. Not all that critical for hunting applications (<300 yards) but might factor into longer range shooting.

 

[fourfive8]

For me, powder temperature sensitivity is a much more important/critical consideration for hunting ammo than for any target or plinking ammo I may load. It is the reason I only load Hodgdon Extreme, temperature insensitive powders for most of my loading and exclusively for all my hunting ammo. The only exceptions are the 5744 I load in low pressure cast bullet loads and light Trailboss loads in small, high expansion ratio handgun ammo like cast 38 Spl and 45 ACP.

In my mind an errant shot on a paper target can’t be compared to an errant shot on a game animal, not to mention a locked up bolt during a hunt due to a high pressure event because of high temperature .

Got rid of practically all other powders years ago- many varieties. A shooting buddy happily traded and/or relieved me of a bunch of IMR 4064 which I gleefully replaced with Varget. Did the same with all my IMR 4895, IMR 4350 and IMR 4841 - replacing them with H 4895, H 4350 and H 4831 SC. Likewise, got rid of all double base ball powders- have not had or loaded any double base ball powders in years.

Have not looked back.

 

[sgt_zim]

Interesting. I'd like to find a way to make it relevant. Today at the range I was trying out (again) some trial loads of 307 gr Hammer 404J bullets using start load data for 300 gr bullets at 84 gr IMR 4895 powder. Holding onto that rifle as hard as I could and it still kissed my eyebrow three times. The weird thing is I can shoot 400 gr Barnes X loaded with Accurate 4350 no problem at all. That's 93 gr difference in bullet weights! The Hammer bullets SHOULD have significant LESS recoil, not more. Just now checking the brass I see one primer is flattened.
View attachment 633559
Something's wrong. Better call Hammer tomorrow. IMR 4895 must have some serious "burn rate" punch per grain.

Hammer publishes their own load data. Here's their data for that 307 gr Stone Hammer

What was your COAL for those loads?

Remember, 404J was originally designed for RN, not Spitzers.

 

[Tintin]

And for us Antipodeans using ADI powder (with the local, non-Hodgdon label)

https://www.adiworldclass.com.au/powder-equivalents/

 

[Ontario Hunter]

Hammer publishes their own load data. Here's their data for that 307 gr Stone Hammer
View attachment 633594

What was your COAL for those loads?

Remember, 404J was originally designed for RN, not Spitzers.

Thanks. The OAL was set at 3.53. A little bit shorter. I can pop them out to 3.56 and see if that makes a difference. I only have IMR 4895 but typically the load data is not terribly different when both powders are listed in loading tables for other cartridges. The starting load is much lower in this table than data I had but max of 87 gr is the same. It does not appear that 84 gr IMR 4895 would be anywhere near the max. But that is some fierce velocity for a 300 gr bullet at max load! Typically changing the OAL is more about the jump to lands and accuracy. Barnes, for example, wants thirty-five to fifty thousandths jump to lands for .308 caliber bullets. It's right on the box. My 404 dies are set to SAMMI COL so presumably Hammer needs less jump to lands. Interesting. I'm shooting 80 gr Accurate 4350 for the 400 gr Barnes bullets very comfortably and very accurately. That data also started at 77 gr powder but it was too light - primers were pushing out.

The original Jeffery guns were designed to accept their 300 gr and 400 gr bullet ammo. Presumably 300 gr was not round nose? I cut my Mauser's loading ramp to cycle 400 gr Barnes spitzer point bullets. It may not cycle 450 gr round nose. I don't know and don't care. I would never shoot them anyway.

They said my 1:14 twist rate was fine.

 

[Ontario Hunter]

And for us Antipodeans using ADI powder (with the local, non-Hodgdon label)

https://www.adiworldclass.com.au/powder-equivalents/

Thanks. It appears the burn rate for IMR4895 and H4895 are essentially the same. I'm going to drop down to 80 gr of IMR4895 for these 307 gr bullets and see how they behave. I don't need 2750 fps.

 

[sgt_zim]

I wouldn't think the 300 gr wouldn't matter much, it's having to fit a 400 gr RN in it.

Close the bolt, then take a wooden dowel, insert down to the bolt face. Inscribe a circle on the dowel at the crown. Take out the bolt, drop in a bullet, then gently re-insert the dowel until it just touches the meplat, inscribe another circle and measure that for COAL. Maybe do that 3 or 4 times and come up with an average.

Even with Hornady's DGX 400 in my MRC, I'm still at ~3.57" with the bullet sitting on the lands. With the long, tapered ogive on Hammer, I bet your out around 3.59 or so, maybe even 3.6. I bet you have a lot of extra COAL you're just not taking advantage of.

I did the same thing for my 9.3x62 - SAAMI COAL is 3.291. Originally designed for RN, that's probably as far as you can go. But with both 258 gr Stone Hammer and 286 gr A Frame, both were right at 3.38" with the bullet sitting on the lands. By availing myself of the additional length in the throat, I was easily able to reach nearly 2500 fps with the A Frames, and over 2500 with the Stone Hammers, with no sign of pressure on either load. I'm certain I could get to 2600, maybe even 2700, with the Stone Hammers. But I figured that a 258 gr bullet scooting along just north of 2500 was plenty, so I quit testing.

 

[sgt_zim]

Thanks. It appears the burn rate for IMR4895 and H4895 are essentially the same. I'm going to drop down to 80 gr of IMR4895 for these 307 gr bullets and see how they behave. I don't need 2750 fps.

Yeah, Hammer's top end with H4895 was *only* 2720. Even 2600 fps with a 307 gr bullet is gonna knock the snot out of whatever you shoot with it.

 

[Ontario Hunter]

I wouldn't think the 300 gr wouldn't matter much, it's having to fit a 400 gr RN in it.

Close the bolt, then take a wooden dowel, insert down to the bolt face. Inscribe a circle on the dowel at the crown. Take out the bolt, drop in a bullet, then gently re-insert the dowel until it just touches the meplat, inscribe another circle and measure that for COAL. Maybe do that 3 or 4 times and come up with an average.

Even with Hornady's DGX 400 in my MRC, I'm still at ~3.57" with the bullet sitting on the lands. With the long, tapered ogive on Hammer, I bet your out around 3.59 or so, maybe even 3.6. I bet you have a lot of extra COAL you're just not taking advantage of.

I did the same thing for my 9.3x62 - SAAMI COAL is 3.291. Originally designed for RN, that's probably as far as you can go. But with both 258 gr Stone Hammer and 286 gr A Frame, both were right at 3.38" with the bullet sitting on the lands. By availing myself of the additional length in the throat, I was easily able to reach nearly 2500 fps with the A Frames, and over 2500 with the Stone Hammers, with no sign of pressure on either load. I'm certain I could get to 2600, maybe even 2700, with the Stone Hammers. But I figured that a 258 gr bullet scooting along just north of 2500 was plenty, so I quit testing.

I have been calipering the cartridges themselves, not cartridge in the chamber. Am I doing it wrong?

 

[sgt_zim]

need to probably do both. but you really need to see how far out you can set your COAL.

remember, you only want to drop a bullet down to the lands, not the entire cartridge, and measure the difference between that and what the dowel length is all the way to the bolt face.

Woodleigh has a very good description in the manual on doing this. And there are probably dozens of YT videos on it as well. You can probably skip Larry Potterfield's YT video - he's advertising for his COAL tool (I have one, but don't have the threaded brass for my 404)

All of my "old" cartridges (6.5x55, 9.3x62, and 404J) have a lot more throat available to seat bullets out longer than SAAMI indicates. The original design for those was to accommodate heavy (long) RN bullets. Spitzers didn't even come out until 1898, but it took a number of years for them to gain popularity.

WJ Jeffrey and Otto von Bock either didn't get the memo on Spitzers, or ignored it.

 

[AimSmall]

Thanks. The OAL was set at 3.53. A little bit shorter. I can pop them out to 3.56 and see if that makes a difference. I only have IMR 4895 but typically the load data is not terribly different when both powders are listed in loading tables for other cartridges. The starting load is much lower in this table than data I had but max of 87 gr is the same. It does not appear that 84 gr IMR 4895 would be anywhere near the max. But that is some fierce velocity for a 300 gr bullet at max load! Typically changing the OAL is more about the jump to lands and accuracy. Barnes, for example, wants thirty-five to fifty thousandths jump to lands for .308 caliber bullets. It's right on the box. My 404 dies are set to SAMMI COL so presumably Hammer needs less jump to lands. Interesting. I'm shooting 80 gr Accurate 4350 for the 400 gr Barnes bullets very comfortably and very accurately. That data also started at 77 gr powder but it was too light - primers were pushing out.

The original Jeffery guns were designed to accept their 300 gr and 400 gr bullet ammo. Presumably 300 gr was not round nose? I cut my Mauser's loading ramp to cycle 400 gr Barnes spitzer point bullets. It may not cycle 450 gr round nose. I don't know and don't care. I would never shoot them anyway.

They said my 1:14 twist rate was fine.

Read the hammer chart carefully. It does not list maxload, only % of fill at starting load. A chrono would be needed to find max velocity.

 

[sgt_zim]

Read the hammer chart carefully. It does not list maxload, only % of fill at starting load. A chrono would be needed to find max velocity.

Yeppers.

Steve Davis' guidance is "start at the bottom, work up in half grain increments, stop when you see pressure signs, then back off a half grain or grain."

 

[AimSmall]

If I understand correctly, the"burn rate" chart has nothing to do with how many grains of powder to use when switching from one powder to another. It would only be used as a guide as to what other powders may be suitable for the application. ALWAYS refer to tested/proven data for each specific powder/bullet combination when changing powders. At least use Quickload or similar software for comparison if such data is not available.

 

[Inline6]

Interesting. I'd like to find a way to make it relevant. Today at the range I was trying out (again) some trial loads of 307 gr Hammer 404J bullets using start load data for 300 gr bullets at 84 gr IMR 4895 powder. Holding onto that rifle as hard as I could and it still kissed my eyebrow three times. The weird thing is I can shoot 400 gr Barnes X loaded with Accurate 4350 no problem at all. That's 93 gr difference in bullet weights! The Hammer bullets SHOULD have significant LESS recoil, not more. Just now checking the brass I see one primer is flattened.
View attachment 633559
Something's wrong. Better call Hammer tomorrow. IMR 4895 must have some serious "burn rate" punch per grain.

Sir in 34 years of reloading, that is the flattest primer I have ever seen. I'm not sure what the reloading data says, I would back of a lot. Like 4gr and see what you get.

 

[sgt_zim]

Sir in 34 years of reloading, that is the flattest primer I have ever seen. I'm not sure what the reloading data says, I would back of a lot. Like 4gr and see what you get.

I posted Hammer's reloading data above. Coal was too short and looking like too much powder as well.

 

[Puddle]

I prefer to think of the Hodgdon "Extreme" powders as "temperature-resistant", rather than "temperature-insensitive".

When I'm out there wandering around all day in the early or late season when it can get a bit toasty, it's comforting to know that the rounds in the magazine and on my belt are minimally impacted by the temperatures.

Still affected by ambient temperatures, but minimally.