Finally got a little chilly weather....

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  • GSPHunter
    Warrior
    • Jun 2014
    • 106

    Finally got a little chilly weather....

    Hello everyone,

    Well, Finally got to do a little real world cold weather ( -35F) testing yesterday and thought I'd share what I saw and see if anybody else had some extreme cold AR rifle tips. Rifle and ammunition sat in the truck bed for about 8 hours prior to shooting.

    The 32.0gn CFE223 under a 123sst load 5 shot group center was ~4.25" above POA at 100yards, and ~6.25" below POA at 300yds. Temp was -35F and Barometer was 30.25 with an altitude of 435'. Running the numbers looks like about 2375FPS at the muzzle. This load runs around 2550FPS in the 60-70 degree range from my 20" J&T.

    Accuracy was pretty ok, and the group at 300 put 4 shots into 2.5" with the 5 hitting about 4 inches to the left.....could've been me, could've been a little wind, could've been the rifle....

    The rifle operated fine, I ran a VERY light coat of mobil 1 grease and a little MDL in the bolt ( this runs well in my Garand down to the -40s) I would be interested in what you all have found to be effective....It seems like the two lubes the guys I work with use are 5606 hydraulic fluid or break free. The only out of the ordinary operation was that a handload of 30.8gn LVR didn't lock the bolt back after the last shot.

    The only thing I wish I had done differently would have been to load the magazines and let the sit before using. All in all a pretty fun way to spend an hour....had the range to myself and the sound attenuates so well at those temps that I could hear the bullets hitting the paper at 300 :-)
  • am4966
    Chieftain
    • Jul 2014
    • 1036

    #2
    Fire Clean or Frog Lube you put on and it soaks into the metal them you wipe clean or rib it off. Since it works from the inside out. Here is a good video explaining cold lube towards the end.

    12.5" SBR Grendel - Need Barrel
    Surge - Rugged Suppressor
    Been a fan of the Grendel from the very beginning and haven't second guessed that choice one time.

    Aim small, miss small!

    Comment

    • rabiddawg
      Chieftain
      • Feb 2013
      • 1664

      #3
      Interesting thread.

      Here in louisiana i will never reach -35 but i have noticed i shift in point of impact from sunny 66 to rainy 46.

      Does a 20 degree change usually show an effect?
      Knowing everthing isnt as important as knowing where to find it.

      Mark Twain

      http://www.65grendel.com/forum/showt...2-Yd-Whitetail

      Comment

      • PredatorDown
        Warrior
        • Jun 2014
        • 239

        #4
        You're way tougher than I am. The coldest I've shot in was -2, and that lasted all of about ten minutes!

        Comment

        • Errorhead
          Bloodstained
          • Dec 2012
          • 95

          #5
          -35? Good grief, I'm cold at 35! If it got that cold in NC, I would just wait two minutes and whatever I was shooting at would freeze to death and I could save a bullet.

          Comment

          • GSPHunter
            Warrior
            • Jun 2014
            • 106

            #6
            You guys are funny.....Its amazing how quick a person gets used to the temps. When I got home, it was -17 at the house ( in the hills) and I kept thinking how warm that felt! Trust me, the thought of being in 100F with high humidity is as crazy to me as the -35 must seem to you all!

            If I can find the Frog Lube, I'll give it a try. I really wanted to see how the rifle would run with lubes that I have around all the time, and red Mobil 1 synthetic chassis grease is always on hand.

            From what I've seen, a rule of thumb of around 3.15 FPS change for every degree C looks about right for both Leverevolution and CFE223 powders.

            Comment

            • FW Conch
              Warrior
              • Nov 2014
              • 289

              #7
              Any idea how that compares with powders that are labeled "Extreme" ?

              Thanks ... Jim

              Comment

              • GSPHunter
                Warrior
                • Jun 2014
                • 106

                #8
                Ok Jim, I had a little H4895 on hand so I thought I'd try it out. I have no experience with this powder in the Grendel, but judging from other loads, I chose to check 28.0 gn H4895 with a 123sst and cci 450 primer.

                the room temp loads clocked at 2440fps muzzle velocity. After sitting out at -20F for 80 minutes that same load went 2350FPS at the muzzle. Not to bad, ~1.8 FPS change per degree C. Definitely better than the ball powders, but still not exactly what Hodgdon says.

                I think all these powders are pretty usable, within 300 yards with the lvr and cfe, I feel very comfortable shooting at big game out to 300 yards as long as the temp is above -30. Colder than that and maybe a limit of 250.

                Before this week, I had been thinking about building a 16" barreled grendel, but now I'm not so sure. If I ever see XBR on the shelf, I'll try to see how it does.
                Last edited by GSPHunter; 01-29-2015, 09:13 PM. Reason: needed todays temp

                Comment

                • FW Conch
                  Warrior
                  • Nov 2014
                  • 289

                  #9
                  Thanks Hunter. That's good info. My shooting will likely all be done at above +20F, so I doubt I will see the temp extremes you reported on, but it gives me a base line of what to expect.

                  Thanks again ... Jim

                  Comment

                  • LRRPF52
                    Super Moderator
                    • Sep 2014
                    • 8569

                    #10
                    With those temperature considerations, it looks like 18" would make sense, but that isn't much different than 20". Thanks for the detailed posts and extreme cold testing. I do a lot of extreme cold shooting in the Arctic in Scandinavia when I'm there, so this is very relevant to a lot of people.
                    NRA Basic, Pistol, Rifle, Shotgun, RSO

                    CCW, CQM, DM, Long Range Rifle Instructor

                    6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

                    www.AR15buildbox.com

                    Comment

                    • GSPHunter
                      Warrior
                      • Jun 2014
                      • 106

                      #11
                      LRRPF52, I always wondered how you guys that shoot REALLY long range compensated for temp changes. I'm not sure if the MV to Temp changes are linear. If if warms up a little next week, I'm going to try to get some data in the low teens.

                      Talking with some people here, a couple of guys suggested developing winter loads. Maybe using 20F as the change point and using paint to differentiate. A little scary to me, but a way to make the shorter barrels more effective in the winter.

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