IMR Vs Hogdon 4350

Discussion in 'Reloading' started by statjunk, Jul 27, 2010.

  1. statjunk

    statjunk Well-Known Member

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    Hello,

    I've been shooting IMR 4350 and getting good results. I hear that it's temp sensitive. I also hear that H4350 isn't temp sensitive at all.

    First of all, how big of an issue is the temp sensitivity?

    Second, if I've gotten good results from IMR 4350 can I expect the same results with H4350?

    In case it matters, this is for use in a .30-06.

    Thanks

    Tom
     
  2. RT2506

    RT2506 Well-Known Member

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    Be aware that these powders are not the same burn rate. They do not use the same data. It will be close but not exact. Many get better accuracy out of H4350. If you shoot in a wide range of temps then yes temp sensitivity is an issue. It is mainly affected with high temps. The longer the range you shoot the more temps will effect your point of impact. Higher temps raise pressure. One load that is OK at 70* may have too high pressure at 90*.
     

  3. Freebore

    Freebore Well-Known Member

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    Effects of Temperature on Velocity and Pressure .......a little info on Temp Sensitivity.

    Some rifles prefer one 4350 over the other. My 243 Sako doesn't like IMR but likes the Hodgon. My Winchester likes only the IMR 4350. You gotta give'm what they like (the gun) not what you want. That's what reloading about finding what the rifle likes.
     
  4. bowhunthard

    bowhunthard Well-Known Member

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    Temp sensitivity is a big issue, not necessarily for accuracy, but for consistent point of impact, especially for long range shooting (as previously stated). I shoot Hodgdon powders almost exclusively in my rifle due to the fact that they are "extreme" powders. I have the ability to shoot my rifle from 0 - 90 degrees and not worry about a major shift in impact.

    These powders are completely different powders with different burn rates. Just because one shoots, doesn't mean the other one will. Try it.

    Good luck.
     
  5. Mikecr

    Mikecr Well-Known Member

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    IMO, all you've heard w/regard to H-vs-I goes without basis..

    H4350 & IMR 4350 are not at all the same(which should make us wonder what '4350' means).
    I found, and others have as well, that IMR4350 is more temp stable than H4350.
    So who really knows?

    If I were you I'd stick with IMR4350, if you're happy with it.
    Now all you gotta do(with any powder) is figure out how to keep your ammo near load developed temperature..
     
  6. coyotezapper

    coyotezapper Well-Known Member

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    This topic has been tossed around alot here lately and it seems that the same people keep bashing hodgdon extreme powders when they have not tested them. Testing does not mean what you are seeing out of one rifle. Are Hodgdon powders the only powders that are less temp sensitive? No, but from the testing I have done they do live up to their billing. I have also found the VV N500 series to be stable in what little testing I have done with these. Powders can be like bullets in some guns, some are less temp sensitive in some barrels and some are not. They have to be shot and tested to see. I love RL22 in my 7MM STW but the velocity is all over the place when temps go up or down so I don't use it. I was discussing this subject with a field staff member of Barnes Bullets two nights ago and he said that they had done a test on this subject including primers. I asked if it was accessible on the internet and he said yes it was actually sent out in their July newsletter. There is only a few Extreme powders listed but as you will see they are very stable powders. Ramshot Magnum intrigued me in this test being that it is a ball powder. I wil be trying it in the future. So here is the link below. In the future it would be helpful to the newer handloader that we keep our opinions seperated from the facts. Just because one powder showed less sensitivity in one barrel/gun compared to an Extreme powder does not make it the rule of thumb. These things need to be stated so as not to confuse the new handloader. I have been handloading for over 30 years now and I am learning something new all the time. Do I know everything, NO WAY!! but if I don't believe something or think it is hype I will test it first to discount it before giving my two cents. Just as a side note, in looking back in my records I noticed that I got more velocity with the Extreme powders before they were labeled as Extreme. This could be just a change in manufacturing lots or it could have something to do with coating that is put on these powders. HMMM!!

    http://www.barnesbullets.com/resources/newsletters/july-2010-barnes-bullet-n/
     
    Last edited: Jul 27, 2010
  7. statjunk

    statjunk Well-Known Member

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    Coyotezapper,

    Thanks for posting that info. I will never again question the temperature stability of a powder. The IMR 4350 showed a 130fps change with a temperature range of 160 degrees. That is ridiculous. There was only 80fps change from ambient to -40 degrees.

    Unless I were shooting at game past 800 yards I couldn't see how this would even be an issue for game size targets. If you're shooting long range for accuracy then it still doesn't matter because when you get there you'll adjust your sites.

    Glad you posted this info.

    Tom
     
  8. Mikecr

    Mikecr Well-Known Member

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    I'm not bashing Hodgdon. They are as good as any other powder out there.
    But they may not be the best any particular gun. Don't matter if they call it 'Extreme' or 'Super-duper' or whatever..

    This thread is about 4350, and there is yet a basis that suggests H4350 is better, or worse, than IMR4350. Right?
    The Barnes testing linked did not compare the two. Right?
    Hodgdon has provided no basis for their claim whatsoever. Right?

    Well, here is some testing that does atleast compare the two in question:
    http://www.shootingsoftware.com/ftp/Pressure Factors.pdf

    As far as opinion? Well ya never know. Mine, and anyone else's, might just trump hype!
     
  9. Ernie

    Ernie <strong>SPONSOR</strong>

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    I use a lot of H-4350.
    I haven't tested 4350 in extreme temps, but I have with Retumbo (another one of the extreme line) and I had no change in my 7mm Dakota when chronoing.
    Temp ranges were from 20's-to upper 70's.
    Only did this with this gun, but it was pleasing to see the results
     
  10. Freebore

    Freebore Well-Known Member

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    Ernie,
    Ok I'll bite, do think that 20-mid 70's is an 'Extreme spread in temp? I think that more like 20 to 90+ is the temp range you really need to be doing testing in.
    The BR guy's had a good time here last Sat for 200 yard IBRS sanctioned shoot... 87deg by 9am and went to 96 deg plus 70+ humitidy now that's 'Extreme' I would think, my 2c.
     
  11. Ernie

    Ernie <strong>SPONSOR</strong>

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    Kev,
    It should have had more temp range-for sure to be a true test.
    I can't even tell you all the reasons at this time why I re-chronoed the load, other than, I did.
    I remember being extremely pleased at the results though.
    Used an Ohler Chronograph.
     
  12. bigngreen

    bigngreen Well-Known Member

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    I've taken Retumbo from the -31 degrees to 92 degrees the other day and had no changes that I could see on the chrony or pressure signs, that is why I've gone with the Hodgen Extreem powder over IMR which I've seen as little as 30 degrees mess things up with.
     
  13. Mikecr

    Mikecr Well-Known Member

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    How does your Retumbo result relate to the subject?
     
  14. bigngreen

    bigngreen Well-Known Member

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    H4350 and Retumbo are, as you know, in the same line of powder formulated to be extremely temp stable. So you should be able to have some expectations from the fact that both are formulated to handle temp swings the same. Temp swings are extremely important for long range hunting, I have used H4350 over IMR4350 in my WSM because of the possibilty of temp stability problems over groups for hunting and predicting first round hits on game animals. Both shot well and held to hunting standards to my effective range but I can have a 45-50 degree temp swing in one hunting day so having a powder change POI on me mid day is unacceptable even though I can take it into account with my ballistics program, I choose not to. In the end I found Retumbo out performed H4350 in velocity so that is my powder of choice for my main hunting rifle.

    I admit that I did not take the time to check exactly how much change I had due to temp with IMR powders or IMR4350 but I have shot enough of the Extreme powders to know that I have not experience any of the temp problem with the line. Conclusive, NO.