H414 powder vs IMR

ern98ern98 Member Posts: 1,725 ✭✭✭✭✭
Hello, I was reading the other day where H414 is supose to have the same burn properties as H4350 but is a much smaller extrusion. Is this the correct? Is there an IMR powder similar to IMR4350 but in the smaller extrusion size? In smaller case cartridges I currently use IMR4320 instead of IMR4064 because it meters out better because of the small extrusion size. I would like to have such for the 4350 as well. Unfortunetly my local sources for powder tend towards IMR and so H414 isn't readily available without a special order.


  • nononsensenononsense Member, Moderator Posts: 10,648 ******
    edited November -1

    H-414 has SIMILAR burn rate properties when compared to H-4350.

    "H414 yields similar results to H4350 in most cartridges, although charge weights will vary."

    from http://www.hodgdon.com/smokeless/rifle.php

    H-414 is a spherical powder not an extruded powder. The spheres are varied in size and also slightly flattened.

    There is not a transitional IMR powder with the characteristics that you mention about the Hodgdon powders.

    Physical description:

    IMR-4198, 3031, 4895, 4064, 4350 and 4831 are all single base powders with nitrocellulose making up 92% of the content. All of these powders are approximately 0.085" in length, 0.032" in diameter with a 0.006" diameter hole running through the center of each extrusion. The exception to this list is of course is IMR-4320, which is only ? of the length of the others at about 0.042" long.

    The one and only factor that differentiates all of these powders in burning rate is a deterrent coating (DTN or dinitrotoluene) applied to the exterior of the extrusions which controls burning rate in the early stages of combustion. That's all. IMR makes 6 powders, all the same chemistry and size but changes the burning rate with a coating.

    On the scale of relative quickness with 4350 being 100:

    ? 4195 is 160
    ? 3031 is 135
    ? 4064 is 120
    ? 4895 is 115
    ? 4320 is 110
    ? 4350 is 100

    With all this in mind, your best bet is to use another powder from another manufacturer. If your supplier can't get over having just IMR in stock, maybe a gentle reminder that times are changing and he needs to start stocking other powders without additional ordering charges just like the other stores do. Start him off with an order.

    SIMILAR powders:

    - Re-19

    - Ramshot Hunter

    - AA 4350

    - Norma N-204

    - V V N-160

  • PinheadPinhead Member Posts: 1,485 ✭✭✭✭✭
    edited November -1
    As usual nononesense has a great asnwer. The only thing that I would add is that powders can vary slightly from lot to lot even with the same manufacturer and number (IMR4350 for instance), let alone a different maker --say H4350. Changing physical form, even with the same ingredients, would change the surface area and change the burning rate. You could add or subtract coating to adjust the burn rate but there would still be a slight difference. I worked in the chemical industry for 32 plus years and the one thing I learned was that nothing--I mean nothing --is absolute when it comes to chemical reactions. Each batch will be slightly different from the batch previous or after even when each ingredient is carefully weighed or measured.
  • nononsensenononsense Member, Moderator Posts: 10,648 ******
    edited November -1
    "...nothing--I mean nothing --is absolute..."

    Except being absolutely correct about your observations! That's why the phrase 'start low and work up carefully' gets repeated frequently when loads are passed on. There isn't any guarantee that the same powder will have the same characteristics. That's also why the factory reloaders blend huge amounts of powder in order to achieve just the right set of characteristics for consistancy. It also goes to the point when posters ask for 'accuracy' loads from fellow posters expecting to save time in load development. Ain't going to happen.

    The 4350's and other long stick powders have another problem as well (as you mention) when the kernals get sheared by the powder measure, the burning rate is altered.

    These are all good reasons to actually READ your reloading manuals cover to cover. Most folks will be surprised at the vast amount of information included with the load tables. Another good source is Wolfe Publishing - Propellant Profiles which has full descriptions of most powders as well as some suggested loads. Unfortunately it has not been kept up to date.

  • ern98ern98 Member Posts: 1,725 ✭✭✭✭✭
    edited November -1
    Thanks for the excellent answers. Ern
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