Range Report 05/06/11

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  • Range Report 05/06/11

    Having already seen how accurate the 123 Amax over 8208 can be, I shot plated some with Hexagonal Boron Nitride and loaded them over the same charges of 8208 again. I was pleased to see not much change in ballistics, but surrised to see a fall off in accuracy. Granted conditions were slightly different at the range in that there was a gusty (10-15mph) tail wind, but it didn't seem enough to make a difference at 100 yards.

    I did the same thing for the Nosler 120gr Ballistic Tip, having recorded some velocities a month ago for non-plated. Unfortunately, there are no accuracy comparisons for these as the first outing had problems from my brake that blew up the groups. Having corrected that, I was nevertheless pleased with the groups across a modest range (1.5gr) of powder.

    Here's some images:

    First the 123 Amax results





    And the 120 NBT results





    Neither sets are studies in extreme accuracy but it felt good to get out and throw some lead. I can't tell you how pleased I am with the inherent accuracy of this caliber. It can make anyone feel like Vassili Zaitsev.

    The jury is out on the HBN. These rounds don't build up copper terribly without it and in the case of the 123 Amax's, I suspect the beating they take in the rotary tumbler could possibly have contributed in the looser groups. Of course, it could have just been a bad day for me. I have tumbled some NBT 100s also, but only have 50 brass to work with, so they will have to wait until next time out for testing. I think in the case of the NBTs, they being only set back .010 from the lands makes them more susceptible to higher pressure and perhaps that's why they did so well with the HBN. Though not as slippery as MoS and my favorite WS2, it is still a little more slippery than bare copper. Perhaps I have yet to shoot enough rounds in one setting to see appreciable copper buildup before cleaning.

    With case capacity already at maximum to get the speed we like, more slippery rounds and their inherent contribution to needing more powder to hit the same velocity may preclude MoS and WS2 which do contribute to less friction.

    I'm just enjoying playing with processes that have sometimes proven useful in other calibers. Those 123 Amax's don't really need any improving, judging from my first outing with them. Without re-shooting the NBT 100s and 120s without HBN for a comparison, it's hard to tell if the accuracy benefits at all from it. Something else to try on another outing.

    humbly submitted,

    Hoot

  • #2
    Does the hexagonal Boron Nitride have the same reputation for the "ring of death" in rifle throats that moly used to? I don't have a bore scope, so I don't even know if the "ring of death" rumors are true or not. I quit using the moly bullets because they didn't seem to do anything good for my groups, and I didn't want to risk ruining a barrel if the "ring of death" rumors were true.

    The other process I am interested in finding out about is the ceramic coating that goes inside the barrel bore. When I cost it out, the re-application required made it not that cost effective. By the time I pay for the continual re-coating of the barrel bore, I could darned near buy a new barrel...so I didn't see the cost effectiveness of that product.

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    • #3
      This is not criticism so please don't take it as such.

      I use 8208 also. Looking at you loads for the amax I think you started out over max with 29gr and the kept going up, my max behold an amax is 28.5, I see you started short stroking with the two higher charges, did you have any other noticeable issue?

      Also what rifle are you shooting?

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      • #4
        Originally posted by noone
        Does the hexagonal Boron Nitride have the same reputation for the "ring of death" in rifle throats that moly used to? I don't have a bore scope, so I don't even know if the "ring of death" rumors are true or not. I quit using the moly bullets because they didn't seem to do anything good for my groups, and I didn't want to risk ruining a barrel if the "ring of death" rumors were true.
        I read about that also and at first was worried, but I can honestly say I never experienced it with either MoS, WS2, or HBN in any of the calibers I used them on. I just assumed it was because I don't shoot large quantities ever without cleaning afterward. I don't have a bore scope, but I actually do give my barrels a thorough looking over after cleaning them, as much for the satisfaction as looking for problems. Whatever the reason, at least it gets done.

        Originally posted by nimrod
        I use 8208 also. Looking at you loads for the amax I think you started out over max with 29gr and the kept going up, my max behold an amax is 28.5, I see you started short stroking with the two higher charges, did you have any other noticeable issue?

        Also what rifle are you shooting?
        In reverse order. The rifle I built from components. The barrel is a 24" SS AA (ER Shaw) with AA bolt.

        The only signs of over pressure were the short strokes at and above 30gr, both with and without the HBN on the Amax. 29 and 29.5 produce brass that looks fine in every regard under my stereo microscope other than what looks like a few scratches from the barrel extension that I'm still trying to find the exact source of. When I was working up to those loads, the brass looked pretty much the same from when I started at 26. Unfortunately, I just tumbled them yesterday, so I can't photograph them for you to see. I was actually hoping the short stroking would abate with the HBN. That's what I was most interested in learning with that experiment. Oh well...

        Hoot

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        • #5
          I used to be compelled to clean my weapons after every firing. Some habits die hard. Perhaps that is what saved my rifles from the "ring of death" when I did try using Moly bullets. I have since stopped buying Moly bullets, and just have a few straggler rounds in my 300 Win Mag rifle...about 10-20 rounds. But as the rifle shoots spectacularly well without Moly, I'm just not going to mess with the success. Why fix it if it works? The 300 shoots 1.3-1.4 inches at 300 yards, so I'm plenty happy with that.

          I have never used any of the Moly bullets in my Grendels.

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          • #6
            Hoot,

            How many rounds have you shot with these loads? I am interested in th 29gr load.

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            • #7
              Originally posted by Nimrod View Post
              Hoot,

              How many rounds have you shot with these loads? I am interested in th 29gr load.
              I'm afraid that being new and only on my third outing with this caliber, that most of my reports are just a single flight of 5. In the case of the HBN experiment, two flights of 5, so the results are far from conclusive and more like anecdotal to my setup. Now that I've established some zones of interest, I plan on shooting more identical loadings to establish a more reliable sample base. Perhaps zoom in between 28.6 and 29.6 in .2 increments. I really need to mooch my Dad's lead sled to remove me from the accuracy equation until I have this thrashed out. I do not consider myself an experienced black gun shooter. Still on the positive slope side of the curve. Wouldn't hurt to have a few more experienced folks paralleling my effort though.

              Hoot

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              • #8
                I am going to keep working with 8208, though I probably won't be using any coatings.

                Watch yourself loading for the black gun though it isn't as forgiving as others. Keep an eye on the lugs of your bolt, in my experience they will be the first to go.

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