IMR4895 and H4895

[Jim Watson]

Ah, but +/- of WHAT spec?
10% +/- is a lot, that is more than the difference in loads from 3031 to 4895.
Powder charge for standard pressure-velocity?
Closed bomb "burn rate?"
"Pressure curve?"

I must have been lucky, both kegs I went through in my F class phase were as close as my chronograph and target could show.

 

[bigpower491]

I was told by Accurate Arms that they blended their powders to plus or minus 5% of their spec. And the technician claimed industry standard was plus or minus 10%. So differences between lots, whether by the same vendor, or different, is to be expected, and is not an artifact of powder being made by subcontractor A or subcontractor B.



Bourbon is also blended to an average taste, unless the distiller is selling it as single barrel. But those single barrel bourbons are chosen so they are close to the brand taste. The stuff that tastes like rot gut, I assume that gets blended with something equally bad, but on the other end of awful, in the hope it all averages out. I did not ask that question on my distillery tours, it would be interesting to find out what they do with the bourbon that tastes like Jimmy Hoffa in a barrel.

I'll never look at a bottle of Makers the same again........

 

[Slamfire]

I'll never look at a bottle of Makers the same again........

It is a shocker to find out just how many things are blended. Heinz ketchup and mustard are blended to an "average" and characteristic flavor. Tomatoes, mustard seeds, and everything else grown varies in taste, texture, smell, etc. Nature is just that way. So it has to be blended.

Kambot pepper, four different types, all grown on the same tree. The different types have a different flavor, and though Kambot pepper is a black pepper, because of the soil there, it tastes different from black pepper grown elsewhere. Nature is highly variable.

 

[bigpower491]

It is a shocker to find out just how many things are blended. Heinz ketchup and mustard are blended to an "average" and characteristic flavor. Tomatoes, mustard seeds, and everything else grown varies in taste, texture, smell, etc. Nature is just that way. So it has to be blended.

Kambot pepper, four different types, all grown on the same tree. The different types have a different flavor, and though Kambot pepper is a black pepper, because of the soil there, it tastes different from black pepper grown elsewhere. Nature is highly variable.

I get that. But Jimmy Hoffa in a barrel....I just drove by the sight of the Machus Red Fox the other day, his last known whereabouts......had to chuckle at that

 

[Slamfire]

Ah, but +/- of WHAT spec?
10% +/- is a lot, that is more than the difference in loads from 3031 to 4895.
Powder charge for standard pressure-velocity?
Closed bomb "burn rate?"
"Pressure curve?"

I must have been lucky, both kegs I went through in my F class phase were as close as my chronograph and target could show.

Charge weight against a standard pressure curve. Their pressure curve of course, and their standard. Which would be in their technical specifications included in the contract documents for vendors to bid on.

That way, they maintain uniformity when they change vendors. Assuming they have written the tech spec tightly enough and comprehensively enough that nothing unexpected happens when the new vendor follows the contract requirements. That is a another reason for bidding conferences, present what you want from your vendor. If no one bids on it, that's a fail.

 

[243winxb]

A variation of +/- 5% seems about right, as the worst possible.

This paper reports on the variations in average velocity for six different lots of Hodgdon Extreme H4831 tested in .25-06 and .300 Winchester Magnum loads

https://apps.dtic.mil/sti/citations/ADA572333

 

[Slamfire]

A variation of +/- 5% seems about right, as the worst possible.



https://apps.dtic.mil/sti/citations/ADA572333

The guy only has a chronograph, but he is smart enough to look at computer models. The thing is, the pressure curve is exponential. A linear increase in velocity will have an exponential increase in pressure. And that pressure increase is not something that can be measured with a chronograph.

As the guy writes:

To consider the likely pressure variations, consider that QuickLoad V3.6 predicts a muzzle velocity of 3174 ft/s and a peak pressure of 54371 psi for 79 grains of H4831 using the 155grain AMAX in the .300 Win Mag. This is very close to the 3177.5 ft/s velocity that results from averaging the measurements over all six lots of powder. However, compensating for possible lot to lot velocity variations requires a range of powder charges spanning from 77.5 to 80.5 grains of powder and a range of pressures from 51063 psi to 57910 psi. It is possible that a load showing no signs of pressure with one lot of powder might not be safe with another lot of powder. At their web site, Hodgdon recommends working up new loads when the lot number of any component is changed, and it is evident that this includes a new lot of Hodgdon Extreme powder

 

[Jim Watson]

Lessee, now a 111 fps spread over six lots of powder, that is "only" 3.5% but the Quickload pressure spread is 12.5%.
Worse than I would have expected.


I went back and looked at some loads. A2495 is now made in Canada which means it comes out of the same plant as IMR 4895. Unfortunately, Hodgdon has apparently not retested the Accurate powders with the same components as they use for H and IMR. But at the greatest similarity - same bullet, top loads differ by over a grain.

Hodgdon gets a lot of powder from ADI in Australia. ADI was accommodating enough to slow the "burn rate" of their AR2206 to produce AR2206H which is what Hodgdon sells as H4895.

But they would only go so far. They got more environmentally correct in their process for shotshell powders but would not match the Clays series exactly. So now Hodgdon gets stuff they call Clays, International, and Universal from IMR.

 

[243winxb]

What i was trying to say above.

ADI was accommodating enough to slow the "burn rate" of their AR2206 to produce AR2206H which is what Hodgdon sells as H4895.

.

The original *(Australia's version)* 4895 made in Australia was modified for the USA market & made darker. Became H4895.

 

[Fishtales]

I walked into the LGS over in Fort Worth many years ago, asked "I need a powder to load the Garand." Guy at the counter turned around and handed me a can of IMR4895... the rest is history. When I got my M1a... a 16" barreled Socom16, I started with IMR4895, which worked well enough, but I've found IMR3031 to be better for what I'm shooting. My .308 bolt gun was the same... IMR4895 worked, but IMR4064 was better. That leaves the M1 Garand as the only rifle I load IMR4895 for. I consider the 4895's the 'Unique' of rifle powders... It works in so many applications... but it seems like there is always a better powder for a given cartridge when you start digging into it.

You, sir, have found the magic in reloading-experimenting and testing-"digging" as you call it (hopefully while using a reliable reloading manual). Just because one powder works wonders in one rifle does not mean it is the best in others you shoot-even in the same caliber (different barrel lengths, different twists, etc.). You experiment with different powders and their weights (as well as bullets) and then go to the range for testing to see what load works and what load doesn't for each individual rifle and caliber. BLC-2 and IMR4895 were a tie in my Remington 700 in .222 Mag. IMR4895 was also the powder I used to reload for a friend's Remington 788 in .22-250. Another friend told me that IMR3031 was a good powder to try in my Remington 700 in .270 Win. (he was right). 3031 also worked in my Savage 99 in .300 Savage and a friend's .308 Win. also, a Savage 99. IMR4350 loads for .338 Win Mag (shown in Lyman's Reloading Handbook, 44th edition), lead me to use IMR 4350 for that caliber for my Ruger 77.

 

[Charlie98]

3031 also worked in my Savage 99 in .300 Savage and a friend's .308 Win. also, a Savage 99.

Both of my Savage 99's... a .30-30 and a .308... get cast bullets, so I use IMR4198, but if I was loading a hunting bullet, etc, I'd reach for the IMR3031.

When I started loading for my Savage 10 TAC in .308, 150grn bullets with IMR4895 worked well enough, but once I went to the 168grn... IMR4064 was the better choice.