16" factory ammo velocities confirmed on film

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  • pajasonc
    Warrior
    • Dec 2016
    • 203

    #16
    Originally posted by StoneHendge View Post
    Hornady is notorious for lot to lot variation. Last fall I purchased 2 cases of 123 Amax from SG Ammo. They ended up being different lots. They had different color primers. Which likely means different primer manufacturers.
    temp at time of chronograph reading can make a pretty good difference as well. would be nothing for the same ammo in the same gun to be 40 fps faster on a 90 degree day as a 32 degree day

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    • LRRPF52
      Super Moderator
      • Sep 2014
      • 8569

      #17
      Originally posted by 458MinMag View Post
      One more data point, apparently on the low end... 123 Amax factory loads clocked 2387fps average out of my 16inch.
      What temperature outside?

      There are 14.5" and even a cut down 13.7" Grendels that shoot 123gr Hornady at 2420fps, but on a warm day.

      2387fps makes sense for a barrel that doesn't pressure up as fast, or winter temps. There are some barrels that use rifling that isn't as sharp as Enfield rifling, and have enough variation from the average to not pressure up as quickly.

      I have some chrono readings through my 16" using PF 123gr Moly Scenars as follows:
      2522
      2484
      2582
      2518
      2503

      2522fps average on a warm day with that load. Then the next spring with the same load, same rifle:
      2447
      2451
      2454
      2456
      .792" group, 2452fps average

      The first time I chrono'd Hornady AMAX with it on May 25th, 2013
      2365
      2470
      2422
      2470
      2460
      2439fps avg
      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

      • StoneHendge
        Chieftain
        • May 2016
        • 2009

        #18
        "temp at time of chronograph reading can make a pretty good difference as well. would be nothing for the same ammo in the same gun to be 40 fps faster on a
        90 degree day as a 32 degree day "

        Those lots had quite a difference. Used a lot that magnetto'd at 2440 on day 1 of a long range class. On day 2, started truing up at 800 yards. Everything looked good .... then I unknowingly started using a box of the other lot. Everything started sailing high over the truing bar. Instructor redid my card. Then I unknowingly went back to a mag from the other box and started putting everything in the dirt in front of the bar. There was a lot of head scratching that afternoon. Didn't realize what the problem was until I checked my boxes back at the motel that night. Luckily, I had enough of one lot to get me through day 3.
        Last edited by StoneHendge; 08-11-2017, 08:17 PM.
        Let's go Brandon!

        Comment


        • #19
          Originally posted by LRRPF52 View Post
          What temperature outside?

          There are 14.5" and even a cut down 13.7" Grendels that shoot 123gr Hornady at 2420fps, but on a warm day.

          2387fps makes sense for a barrel that doesn't pressure up as fast, or winter temps. There are some barrels that use rifling that isn't as sharp as Enfield rifling, and have enough variation from the average to not pressure up as quickly.
          It was 75 or 80deg that day, so it must be lot-to-lot variation in the ammo, or the individual barrel as you mentioned. I'm not at all worried about it. I've got some Honrandy Black and 123 SSTs that I'll check in the future just to see where they fall. I also shot some handloads with 123 Amax and CFE223 ... 31.2gr gave an average of 2349fps over my Magnetospeed.

          Comment

          • Kilco
            Chieftain
            • Jan 2016
            • 1201

            #20
            Originally posted by 458MinMag View Post
            It was 75 or 80deg that day, so it must be lot-to-lot variation in the ammo, or the individual barrel as you mentioned. I'm not at all worried about it. I've got some Honrandy Black and 123 SSTs that I'll check in the future just to see where they fall. I also shot some handloads with 123 Amax and CFE223 ... 31.2gr gave an average of 2349fps over my Magnetospeed.
            31.2gr CFE223 over a 123 out of a 16" gave you 2349?!

            That exact same load from my 16" with a 123 eld-m at 2.255 in hornady brass with a CCI 450 gives me just under 2500.. my notes confirm my average was 2489.. what make and twist barrel is it?

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            • #21
              Wow, your's is shooting a lot faster! Very nice. I didn't mean to get your thread sidetracked; I clearly have an outlier or chrono issues. Carry-on!

              Comment

              • Kilco
                Chieftain
                • Jan 2016
                • 1201

                #22
                Originally posted by 458MinMag View Post
                Wow, your's is shooting a lot faster! Very nice. I didn't mean to get your thread sidetracked; I clearly have an outlier or chrono issues. Carry-on!
                Truth be told, it's how it shoots that really matters. This 16" velocity hoorah is the result of a pissing contest between me and a 6.8 advocate.

                Guys have been shooting and hunting with guns and cartridges they love for decades not ever shooting over a chrono or caring about velocity. If it puts the the bullet where you are pointing is first and foremost.

                Comment

                • PA_Allen
                  Warrior
                  • Mar 2011
                  • 333

                  #23
                  Originally posted by Kilco View Post
                  31.2gr CFE223 over a 123 out of a 16" gave you 2349?!

                  That exact same load from my 16" with a 123 eld-m at 2.255 in hornady brass with a CCI 450 gives me just under 2500.. my notes confirm my average was 2489.. what make and twist barrel is it?
                  As another point of reference, I get 2430 to 2450 fps out of my 16" with 31.2 gr CFE223 and 123 SST.
                  - PA

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                  • pajasonc
                    Warrior
                    • Dec 2016
                    • 203

                    #24
                    Originally posted by 458MinMag View Post
                    It was 75 or 80deg that day, so it must be lot-to-lot variation in the ammo, or the individual barrel as you mentioned. I'm not at all worried about it. I've got some Honrandy Black and 123 SSTs that I'll check in the future just to see where they fall. I also shot some handloads with 123 Amax and CFE223 ... 31.2gr gave an average of 2349fps over my Magnetospeed.
                    458 what barrel do you have? Also is it a saami spec barrel? I have looked at a lot of chronograph results on the web and I have noticed that a lot of the non saami chambers seem to be slower, not all but many. My thinking, and it may be way off base, is that the non saami chambers aren't building as much pressure.

                    Comment

                    • LRRPF52
                      Super Moderator
                      • Sep 2014
                      • 8569

                      #25
                      When you have a longer throat, it won't convert the powder as fast, so that initial peak takes longer to rise, but you can chase the throat with COL of course limited to what your mag will allow.

                      When I load a 123gr AMAX to 2.275" in that same 16" AA barrel with SAAMI chamber on 31.2gr of CFE at 60˚ F, I got 2500fps.

                      In my Lilja 17.6" barrel with SAAMI chamber, I got 2465fps at 31.7gr of CFE loaded to 2.260" COL with the same 123gr AMAX at 64˚ F.

                      At the end of the day, I don't care to much, just load up my 31.2gr CFE load under 123gr AMAX double-weighing charges, and head to the range or field with steel targets in mind. I have zero desire to jack around at 100yds with a known load that shoots into the head of an IPSC at 500yds easily, and smokes my 12" poppers at 700yds so that after a few rounds, I'm looking for more range. 1100yds is more of a challenge with 123gr AMAX for me.
                      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

                      • DJL2
                        Bloodstained
                        • Aug 2017
                        • 57

                        #26
                        I'm happy to take this up, actually...just gotta find some Hornady 120 gr SST for each first...though the Grendel does seem to have a LOT more options in this bullet weight. I was planning on doing some load testing a development in each caliber anyhow. Frankly, I don't expect a lot of difference...

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