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Thread: Blue Dot and Accurate #9 Temperature Sensitivity Test

  1. #1
    Join Date
    Apr 2006
    North Pole

    Default Blue Dot and Accurate #9 Temperature Sensitivity Test

    I posted this on a different forum but thought I would share here in case it proves useful to someone else. I wanted to test the temperature sensitivity of Blue Dot and Accurate #9 in 10mm but couldn't do so using my Magnetospeed chronograph as mine is the V2 version without an adaptor to attach to the pistol rail. So, I used a 44 magnum and these powders as a proxy.

    I've read Blue Dot is temperature inverse meaning the pressure INCREASES as it gets colder and Accurate #9 is allegedly harder to ignite in colder weather. I emailed Alliant about Blue Dot and they didn't give me a direct answer. So, here's what I did. I loaded up a ladder series of Blue Dot and Accurate #9 in my Super Redhawk 44 Magnum using Leadheads 250 grain Plain Base Keith bullets. Since I've never loaded 44 with these powders, I kept the powder charges below maximum just in case something went sideways.

    The first 5 rounds with each powder are the ladder series and the last 5 rounds with each powder are the maximum load from the ladder series. I shot at the indoor range in Fairbanks for the first warm weather test and yesterday at the South Cushman range for the cold weather comparison. I left the bullets and revolver in the back of my pickup truck at my place for 5 hours at -24ish to cold soak. By the time I got to the range it had warmed up to -15. Here are the results:

    Blue Dot CCI 300 primer

    70 degrees F -15 degrees F
    12.0 grains 1149 fps 1026 fps
    12.5 grains No Reading 1018 fps
    13.0 grains 1226 fps dropped round in snow could not find
    13.5 grains 1224 fps 1252 fps
    14.0 grains 1291 fps 1214 fps

    Five Shot Strings with 14.0 grains of Blue Dot
    70 degrees F -15 degrees F
    1222 fps 1144 fps
    1257 fps 1206 fps
    1246 fps 1225 fps
    1319 fps 1246 fps
    1241 fps 1327 fps

    Average Velocity 1257 fps Average velocity 1229 fps

    Accurate #9 CCI 350 primer
    70 degrees F -15 degrees F
    16.0 grains 1170 fps 1110 fps
    16.5 grains 1310 fps 1189 fps
    17.0 grains 1306 fps 1261 fps
    17.5 grains 1415 fps 1331 fps
    18.0 grains 1439 fps 1353 fps

    Five Shot Strings with 18.0 grains of Accurate #9
    70 degrees F -15 degrees F
    1356 fps 1250 fps
    1429 fps 1297 fps
    1447 fps 1289 fps
    1418 fps 1288 fps
    1416 fps 1339 fps

    Average Velocity 1413 fps Average velocity 1292 fps

    These results aren't really statistically significant but I'm gonna jump to a couple conclusions based on these tests. First, Blue Dot appears to be more temperature stable than I anticipated based on what I had read. I expected increased velocity with every cold weather shot. Two cold weather rounds did chronograph higher than their warm weather counterparts but I don't know if that is a function of the powder or possibly chronograph error.

    Accurate #9 is another story. Every cold weather round lost velocity as compared to its warm weather counterpart. I don't think it is more difficult to ignite this powder as I didn't experience any hangfires or anything out of the ordinary. It just seems to have consistently lost velocity in colder weather. Extreme spread in both of these loads is terrible but they aren't optimized powder charge weights. They're just a test of the powders reaction to cold weather.

    I don't anticipate handgun hunting in temperatures below zero but I wanted to get some indication of how these powders reacted to colder temperatures. I intend to work up loads in the 10mm shooting 200 grain WFNGC bullets and both these powders to see which is more accurate in my pistol. I already tried Longshot and Blue Dot proved to be more accurate. So Accurate #9 is next. Hope this info proves useful to somebody out there.

  2. #2


    Thank you.

  3. #3
    Member Libertine's Avatar
    Join Date
    May 2013
    Anchorage, AK


    Thanks for posting these cold weather chrony results. I've wondered about Blue Dot in cold temps.


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