Will a 6mm shoot a 105 over 3300FPS

Discussion in 'Reloading' started by Greg Duerr, May 1, 2015.


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  1. Greg Duerr

    Greg Duerr Well-Known Member

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    Ive been listening to a friend tell me that a 6mm shooting a 105gr Berger in a 26" Barrel will shoot over 3300fps...........safely

    He keeps telling me that the 6mm is a larger case than a .243 AI and therefore the 6mm will shoot a 105gr Bullet faster than a .243AI My .243 AI with the 105 berger is getting 3300 with 47gr of RL 22 out of a 26" barrel

    keeps refering to the Nosler Reloading manual that shows a 100gr at 3250+

    Every other reloading manual show the 6mm with a 100 at about 3000fps.

    So tell me ..................................will a 6mm toss a 105 faster than a .243 AI?????
     
  2. DrillDog

    DrillDog Well-Known Member LRH Team Member

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    Well it's possible. Every barrel is different. Some barrels will pressure up before others. Twist rate can matter too.

    I shot out my 6.5 Rem Mag barrel a few years ago. Junked the barrel and sold the action. It was pushing 140gr VLDs at 3150 fps with 51gr of RL17 from a 26" 1 in 8.5" twist barrel. I tried 51.5gr at about 3180 fps, but would get loose primer pockets. I decided I wanted to build another one so I bought a new action and barrel then had it all fitted up. Right off the bat the new 26" 1 in 8" twist barrel was way more accurate and easily pushes the 140gr VLD to 3210 fps with "52"gr of RL-17 and no pressure signs. Haven't tried to go faster to find the threshold because that's plenty fast enough for me. But I'm sure it still has a little throttle left before reaching max pressure.

    So from one barrel to the next, I was able to add a full grain of the same powder and gain 60 fps more with no pressure signs.

    I used to have a 300 Win Mag that would push the 180gr Swift Scirocco II at 3230 fps from a 24" 1 in 12" twist barrel. Tried the same exact load in my father's 300 win mag wearing a 24" 1 in 12" twist barrel and it only gave a speed of 3060 fps. Big difference.

    I also have a 6mm Remington that pushes 75gr Sierra HP bullets at 3475 fps from a 24" barrel. Might go a little faster, but I haven't tried because im using a max listed load of IMR 4895. Now add 2" of barrel length to make it 26" and that same load may be going 3530-3550 fps. So even though I haven't tried 105s in it because my twist is too slow, I'd say it's definitely possible for the 6mm to push a 105gr bullet at 3300 fps if he has a "fast" barrel.
     
  3. DrillDog

    DrillDog Well-Known Member LRH Team Member

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    And besides, who cares what he says. It's not a contest. Doesn't matter one bit who has the faster rifle. The only thing that really matters is whether or not you can hit exactly where you are aiming. Now if his rifle is more accurate, then he's got something to brag about ;)

    Just like all these kids in cities buying jacked up trucks with big tires and diesel engines that never see anything off the pavement or haul more weight than their girlfriend or dog riding in the passenger seat. The only thing they have to brag about is how much money and fuel they waste for nothing...
     
  4. tbrice23

    tbrice23 Well-Known Member

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    My 6mm AI barrel will be here next week, I'll let you know.

    I'm fire forming so the case will be 6mm rem. until formed to AI.
    However, when fireforming other ackley chamberings and belted magnums I find that a lot of energy is spent on blowing out the case so it just might be slower than a regular 6mm rem.
     
  5. roninflag

    roninflag Well-Known Member

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    a 6mm AI . maybe.
     
  6. MudRunner2005

    MudRunner2005 Well-Known Member

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    I was fixing to say, the 6mm AI might do it. But I have no hands-on experience with one, so I'm just going by what I've seen from other people's posts.
     
  7. FearNoWind

    FearNoWind Well-Known Member

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    Well, Greg, my 6BR shoots 107 gr SMK's nicely at about 2800 fps. There is no way I could safely squeeze our 3300 fps out of it. But I don't need it cuz it's still sonic beyond 800 yards (I've even had good results out to 1K on a good day) so there's no reason to stretch the tolerances. If your friend has certified data for his claim I'd like to see it. A word of mouth claim like that isn't something I generally pay much attention to.
     
  8. Dgd6mm

    Dgd6mm Well-Known Member

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    The 6mm Competition Match with a 28" barrel, 105 Berger, 51 grs. of H1000 Nosler brass = 3308 fps . No pressure issues, per Joe Hendricks testing.
     
  9. stonehands1

    stonehands1 Well-Known Member

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    I would say that is probably right at max load with this combination but possible I suppose.
    I don't know who Joe is or if you even know who Joe is. My point being just because Joe can do it with his rifle, his chrony, and at his altitude doesn't mean that anyone else can.
    I have a 6mmAI and have pushed 95 grainers at 3550 through a 28 inch tube at sea level but with pressure signs and sticky bolt lift. My twist rate is to slow for 105s but it would be possible I suppose... from my 6mmAI.
    When fire forming brass with factory 6mm 95 grainers I believe they run about 3100 in so.
     
  10. Dgd6mm

    Dgd6mm Well-Known Member

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    My 27" I ran at 3225 fps using 49 grs. of H1000. Yes I know Joe, we have talked often. I built my first 6mm Competition Match at the end of '07. Joe won Camp Perry last year (2014) using it. He lives in Pittsburgh, Pa. and I am in Florida, low altitude for me. I've shot 51grs. in my 30", what a fast accurate rifle. My 27" is my tac rifle, I dropped the load a little and settled at 3153 fps and shrunk my vertical by just over 2",ended up with a 10 shot group under 4.5" @ 1000 yards.That was right at 1000 rounds down the barrel. Now it has 3950- 4000 and shoots .4moa at 600 yards. Oh This just popped into my head, this for me has all been done with a 115 DTAC. :cool: I have a lot of testing of my own, I have 3 of these barrels. I have one that is not screwed on yet, it will be ran with 105 Berger Hybrids. I broke the barrel in,unsrewed it and put it away till the tac barrel gives up. It is a shooter, made jaws drop while ff brass at long range using 105 Amax's. I have never done it but Joe has ran 52 grs.. At 51 grs. no problems for me.
     
  11. stonehands1

    stonehands1 Well-Known Member

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    That sounds like a sweet setup you got there. I was running 53 grains of 7828 with the 95's. Maybe a bit slower powder would help with pressure signs. But then again I don't have the twist for the longer bullets.
     
  12. Dgd6mm

    Dgd6mm Well-Known Member

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    Thank you, it is sweet. My 2 Krieger's are 7.5 and my Lawton is 7.65 which the 105's will be shot in. I use 4" drop tube, not sure what Joe uses, but he has told me that he has dropped more then 52grs. in the case. I have giving IMR 7828ssc a thought to try, seeing that H1000 is so hard to find. I just opened my last 8 lb jug.