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Thread: Temperature Sensitivity - Handgun Powder

  1. #1
    Member 8x57 Mauser's Avatar
    Join Date
    May 2006
    Southeast Alaska

    Default Temperature Sensitivity - Handgun Powder

    Unseasoned handloader observation/questions:

    I went out with the .44 magnum today (at just below freezing) until my fingers were too cold to squeeze the trigger smoothly.

    This was the first firing for a batch of RP brass. IMR 4227 launched 240-grainers into some pretty good groups at 40 yards with CCI 300 primers, but I noticed a fair amount of unburned or partially burned powder in the barrel and sometimes the cylinders. These were work-up loads, and I didn't get to the listed max charges from my load data--so the cases were pretty full, but not particularly compressed.

    1) Is the unburned powder a function of temperature? I put half a dozen rounds in each pocket for about 20 minutes and there seemed to be less unburned powder when I fired them - but there still was some;

    2) Do I really need a "magnum" primer to get it all burned? Or,

    3) Should I ignore it - the bullets sure went downrange without a problem.

    I appreciate any insights!

  2. #2
    New member
    Join Date
    Apr 2006

    Default Primer

    I would try a Magnum primer and see. Its worth the $2 just to try them in your load application. I have no expierience w/ 4227, just a suggestion.

  3. #3


    4227 has always been a little tough to burn completely in a straight wall handgun case in my experience, so I always use mag primers with it. Doesn't always burn it up completely even then, but it helps. Never noticed ambient temp to make much of a difference.

  4. #4
    Join Date
    Jan 2005

    Default Unburned 4227


    I would say you very definately needs mag primers, CCI-350's should help.

    H4227 requires a certain pressure level to burn cleanly and that is around 30,000 psi. Basically less than 20 grains in the 44 mag case will be under that unless the bullet is over 300 grains.

    Temperature? Yes could be affected by cold temps but the biggest thing for your experiment was most likely the primers.

    Even with full power loads, there will be some noticable unburned powder. There is with any powder and powders for the 44 mag are no exception. The yellowish colored kernals of H4227 show up so easily when unburned. With H110 ball powder it is small black "balls" so we hardly notice unburned powder.

    H4227 is a very good powder and can be used with any bullet of 240 grains and up and similar loads for all the mag revolver loads. We just fill the case up to where the bullet sits on the powder, and that is a good load. It's bulk density is such that we cannot get too much in a case with any of the big bore mag revolvers.

    It would be good to chronograph loads from this powder over a temperature range of -40 to +70 and see how much they vary.
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  5. #5
    Join Date
    Jan 2007

    Default unburned powder

    Although temp will affect powders to some degree, it is common at all temps to have unburned propellant left. I will shoot as many as 3,000-15,000 rounds daily at my job and during clean up we usually get about 1/2 pound to 1 full pound of powder off the floor in front of the firing line. This seems to be constant and dosent change for the temp (fresh outdoor venting from firing line to target).For those wondering, the unburned propellant is watered in a 5 gallon bucket then given to the fire department after that for controlled burning when it dries out later.

  6. #6


    It's worth pointing out that 4227 (and 2400 for that matter) is very sensitive to degree of crimp in revolver cartridges. Basically, the more the crimp the better the burn. Surprisingly small variations in case length and resulting changes in crimp tension can have a huge impact on velocity and powder burn, whether or not it actually affects group size at shorter ranges.

    Changes in case length from stretching is most apparent if you mix newer and older cases when loading large quantities of ammo. It's been a long time since I did it and I can't find the notes, but once upon a time I loaded 20 rounds each of once-fired, 5-times-fired, and 10-times-fired 44 mag cases with no change in the crimp die. As I recall the load was my standard of 23 gr 4227, 240gr hard cast and CCI 350's.

    As I said, I can't find the numbers now, but even though velocities were pretty consistent between 5 shots of each load, but there was a pretty substantial difference between the once fired and those previously fired 10 times. As an experiment I also fired groups of mixed cases. All groups were fine at 25 yards, but the groups using mixed cases really opened up at 50 yards and especially at 100 yards.

    After doing that, I stopped mixing older and newer cases in my bulk reloading of practice loads. Instead I bought my cases in batches of 500, then kept them together as they accumulated more firings.

    Notice I didn't say anything about trimming cases. I didn't have a power trimmer then, and it was a whole bunch easier simply to manage my cases than to turn a hand crank for hours.

  7. #7

    Default Temp

    To check the temp. properties of your ammo, TRY THIS.Take a few cylinders full of ammo and put it in insulated lunch box with a HOT HANDS. Shoot a couple of cylinders full of cold ammo and then switch to the ammo in the lunch box. Check the difference. GOOD LUCK !!!


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