Why the AMAX 123 over the 120?

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  • Why the AMAX 123 over the 120?

    I see a lot of folks recommending the 123 grain and nothing about the 120's. Are the 123's superior? What about the 123 Lapua Scenar vs the AMAX? I currently shoot 120 SMK's with good results, but can always do better.
  • bwaites
    Moderator
    • Mar 2011
    • 4445

    #2
    Amax 123's were designed specifically for the Grendel and have a higher BC. The 120's are similar in BC to the 120 Sierra. The Lapua's have the highest BC.

    The 120 Sierras shoot very well to 600+ yards, but give up quite a bit of BC to the 123 Sierras and Lapuas.

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    • #3
      Can someone with some 120gr Amaxs, 120 NBTs and a bullet comparator measure the length where they engage the datum point? I ask because unlike the 123s the 120s are readily available and in my chamber the NBTs hit the lands at 2.27 COL, which allows me to load them .010 off the lands at 2.26 and I like that amount of jump. I have not loaded enough to get to the point where I experiment with COL for its impact upon accuracy. I'm still working on OBT with different powders.

      Thanks,

      Hoot

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      • #4
        The 120 gr AMAX works well in my AA Shaw barreled Grendel. I load to 2.270 LOA which puts the bullet .010" shy of whatever it runs into in the throat and also fits into the mags. I got a bunch of them cheap so am glad they work in this barrel. I know some people don't have as good of an experience with the 120 AMAX in their barrels though. I don't use them in my CSS barrel because I have to load them a lot shorter.

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        • #5
          Originally posted by bwaites View Post
          The 120 Sierras shoot very well to 600+ yards, but give up quite a bit of BC to the 123 Sierras and Lapuas.
          There is a BIG jump in BC between the Sierra 120 and the Sierra or Lapua 123's. The Grendel is my FPR rifle, so I was thinking the Sierra 123's might be the way to go for a test. But, you also said in another thread that you had never had much luck with them, but knew others that had. As I said, I have had no issues with the 120's, but every little bit of edge you get helps. I shoot .223 in F-T/R against all those .308's. But I hold my own because I have found the combo load that excels in my rifle. I'm trying to do the same here. I have found AA2520 to be a good powder. I keep my bullets in a cooler between rounds and we shoot under a cover, so temperature deviations are not a big issue for me. I think the difference in BC is enough of a consideration to give them a try. It's just finding Amax's is a real pain, but Sierra's are available.


          Originally posted by ofreen View Post
          The 120 gr AMAX works well in my AA Shaw barreled Grendel. I load to 2.270 LOA which puts the bullet .010" shy of whatever it runs into in the throat and also fits into the mags. I got a bunch of them cheap so am glad they work in this barrel. I know some people don't have as good of an experience with the 120 AMAX in their barrels though. I don't use them in my CSS barrel because I have to load them a lot shorter.
          Thanks, this is what I was wondering. I have not seen much written about them other than an ogive issue that supposedly the 123's fixed. I want a bullet I can pretty much load in either of my Grendels and be pretty sure that accuracy will not fall off much from one to the other. The 120's sound like a crap shoot.

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          • #6
            Originally posted by RStewart View Post
            The 120's sound like a crap shoot.
            I'd say that's a good assessment. Depends on your barrel. Plus, my shooting with that Shaw barrel has been 500 yards or less, so the 120 AMAX works well enough for me. It is a 16" barrel by the way. No match work, just longer range plinking out in the desert.

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            • LRS_Ranger

              #7
              I had a terrible time getting the 123 Scenars to shoot any tighter than 3/4 of an inch. I switched to 120 SMK's and went down to 1/3 of an inch or so. 120 Noslers were repeatedly slapping the 10 ring at 600 on Tuesday night. I would still like to get the Scenars to shoot well, I've just given up on it for now..

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              • #8
                After finding out Saturday in the middle of a FPR match that I had some rounds I had not bumped the shoulder back enough (must have been the 70's rock I was listening to while reloading!) and had to withdraw, I decided to go back to the range yesterday to finish shooting my rounds and to chrono my 120 SMK loads-

                Equipment-
                AA 20" Hunter Upper
                WCI Muzzlebrake
                AA lower w/Magpul PRS stock
                Gisselle SSA trigger
                Caldwell bipod

                Load-
                120 SMK
                30.2 grains of 2520
                2.26 OAL

                I settled on 30.2 recently because I tried loads at 29.5, 29.9, 30.2 and 30.5 2520 and this load grouped the best.

                A friend was there testing some .308 and 300 Win Mag loads, so he helped with the chrono work. Winds were gusty from left to right. The first 10 round string averaged 2599 fps at 10' from muzzle and the second 10 round string averaged 2611 fps at 10' from muzzle. The rifle held 1 moa for all 20 rounds with the last 10 round string sub-moa.
                I know that there have been discussions about the sensitivity of 2520. I load in a 70 degree room and once the weather starts getting hot, I'll keep my loaded mags in a small cooler to keep the temperature as close to the temperature in my reloading room as possible.

                The WCI brake did a great job of reducing recoil and a couple of folks commented on Saturday that it did not sound appreciably louder than rifles without one. I wear double hearing protection when I shoot, so I couldn't tell.

                I am happy with this, but think I may order 100 each of the Lapua 123 Scenar and 100 of the 123 SMK's just to try though.

                BTW- When Ted would shoot his 300 Win Mag, the concussion wave would show up on my chrono as an Err 1 (bullet did not pass over eye). He was shooting from the next bench over.... that's a big wave!
                Last edited by Guest; 04-11-2011, 04:02 PM.

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                • PrecisionFirearms
                  Warrior
                  • Apr 2011
                  • 767

                  #9
                  To answer the question - Do you shoot past the 500 yard line? The BC of the 123s is just plain better at ranges of 500 yards and beyond. Look at 6.8 SPC data and compare it to the 6.5. Notice the similar muzzle velocity and trajectory up to 300 yards. This is caused by BC. Too much drag. That is an extreme example but proves a point. Now for real every day, every shooters situations. The 120 Nosler is overlooked and way underrated. That bullet doesn't have the BC of the sexier 123's but it is extremely accurate! I have plenty of shooters that using our ammo with 120 Nosler BT's can group a consistent sub .5 MOA at 100. Not bad for a hunting bullet. It also has brought down deer and hogs at 400 yards plus (even have a report of 550+ yards and just ten feet after hit with double lung pass through). So do you really need the 123 - depends on the application. Match shooting at 600+ yards - a most definite yes, target shooting and hunting under 500 yards - Use the 120 that you can get. We have a lot of positive reports on the 120 Sierra. Another interesting note is that the 120's are often reported to be more forgiving of twist rates and powder choices. Or maybe less is expected of them? Summary - The 120s are just as accurate but will have more drop due to reduced BC. The 123 Scenars are best matched to 1-8 twist barrels. Most bad reports are those coming from 1-9 Twist barrels.

                  Disclaimer: Not trying to start a war - just stating observed opinion gathered from years of experience and 400,000+ bullets, cases, and ammo sold and tech support given and reports from the field.
                  "Precision - The Pinnacle of Perfection."

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                  • #10
                    I competitively shoot at 600 yards. That's why the 123's high BC looks good.

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