5mm smc

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by goodgrouper, Jun 26, 2007.

  1. goodgrouper

    goodgrouper Well-Known Member

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    I attended a short range br match this weekend and shot with a guy that had an interesting cartridge sitting on the bench with him. I noticed it and recognized it from articles in the Varmint Hunter. I asked the guy where he got his cartridges and he replied that he invented them. I asked, "aren't these the round shoulder cartridges M.L. Mcpherson designed?" He said, "no, I designed it. M.L just advertises them."

    At first I thought he was kidding me. But then he introduced himself and told me the story behind the development of these cartridges and how they got their name. The "S" in SMC stands for Smalley which was his last name. He is the founder and patent holder for Superior Ballistics INC. He worked in rocket building for several defense companies including Morton-thiokol which builds the Saturn rockets that take the space shuttles to space. In other words, this guy knew his internal ballistics!

    He said he simply applied rocket building techniques and shapes to small arms cases and $75,000 later, he had patents for the rounded shoulder. This shoulder is reported to give much higher velocities while keeping the throat cooler. It also gives better standard deviations and extreme spreads.

    There is a whole line of calibers in the SMC line, but the one he was shooting this day was the 20 caliber version based on the 6br case. He claimed that is was launching 50 grain Berger VLD's at 3950 from the 30" barrel with 32 grains of powder. That is roughly 150 fps faster than a 204 ruger will push a 39 grain bullet with 28 grains of powder. If true, that is pretty impressive performance. I had a chronograph in my truck and I really wanted to chrono it, but there was a BR match I was shooting in and didn't have time to mess around with it.

    I did however get to spot for him while he got it on paper and I can honestly say that his bullets were hitting the burm at 300 yards at least three times faster than the bullets from all our 6ppc's so I know it was haulin' arse.

    Anyhow, brass can be bought from Norma (or Lapua-I forgot) and rifles can be special ordered from Savage. Barrel twists are properly set up for heavy for caliber bullets. This might be a good way for a poor man to have a semi-custom long range hammer without going to much trouble. Anyhow, I thought it was interesting. Here is a pic of the ammo:
    [​IMG]
     
  2. BountyHunter

    BountyHunter Writers Guild

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  3. Buffalobob

    Buffalobob Writers Guild

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    [ QUOTE ]
    He worked in rocket building for several defense companies including Morton-thiokol which builds the Saturn rockets that take the space shuttles to space. In other words, this guy knew his internal ballistics!


    [/ QUOTE ]

    [​IMG]
     
  4. Buffalobob

    Buffalobob Writers Guild

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    I have to keep my post count up or else Roy In Idaho will move ahead of me into fifth place /ubbthreads/images/graemlins/grin.gif
     
  5. CatShooter

    CatShooter Well-Known Member

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  6. goodgrouper

    goodgrouper Well-Known Member

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    I probably should say here that while I was intrigued by the design and impressed by one's desire to create something new, I am not totally sold on the SMC cartridges. In the shooting world, one of the biggest bull$hit busters is a chronograph and I really don't believe anything until I see it on a chronograph printout (and it has to be a good chrono at that!) and I did not have time nor the permission to chrono this cartridge at the match.

    Obviously, Mr Smalley knows his rockets but that doesn't always translate directly into small arms. And let's not forget that when engineers get involved in a project, they can and tend to over-engineer something right out of the realm of practicality. Then it is very hard to get the engineer to admit that his brainchild was not the improvement he had envisioned.

    So, until I can put an SMC over my Oehler, it's all just speculation to me but it is fun idea nonetheless.
     
  7. CatShooter

    CatShooter Well-Known Member

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    The problem with Smally's cartridge is that when compared to a .204 Ruger, it looks good... a case that holds 7 grains l(20%) less. But so does a 300 WM compared to a 30-06.

    But when the 5mmSMc is compared to a 20BR, with the same case volume, it gives the same velocities.

    The shooting world, especially the varmint shooters, have always been eager to jump on a better cartridge - but this one has been around for a while, and there still is no interest in it.

    .
     
  8. britz

    britz Well-Known Member

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    buffalobob, You must have whent into the archives to get that picture from 1996 - the quote refers to the challenger explosion happening 10 years ago. Just thought it was a little funny.
     
  9. jb1000br

    jb1000br Well-Known Member

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    [ QUOTE ]
    He claimed that is was launching 50 grain Berger VLD's at 3950 from the 30" barrel with 32 grains of powder. That is roughly 150 fps faster than a 204 ruger will push a 39 grain bullet with 28 grains of powder. If true, that is pretty impressive performance.

    [/ QUOTE ]

    14% more powder and 4% more velocity...doesn't sound like a good deal to me /ubbthreads/images/graemlins/grin.gif
     
  10. CatShooter

    CatShooter Well-Known Member

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    [ QUOTE ]
    [ QUOTE ]
    He claimed that is was launching 50 grain Berger VLD's at 3950 from the 30" barrel with 32 grains of powder. That is roughly 150 fps faster than a 204 ruger will push a 39 grain bullet with 28 grains of powder. If true, that is pretty impressive performance.

    [/ QUOTE ]


    14% more powder and 4% more velocity...doesn't sound like a good deal to me /ubbthreads/images/graemlins/grin.gif

    [/ QUOTE ]

    Yeah... what he said /ubbthreads/images/graemlins/wink.gif

    .
     
  11. goodgrouper

    goodgrouper Well-Known Member

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    Ummm...But it's an 11 grain heavier bullet bud. /ubbthreads/images/graemlins/wink.gif
     
  12. jb1000br

    jb1000br Well-Known Member

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    Missed that part /ubbthreads/images/graemlins/grin.gif

    But how much less barrel did the 204 mentioned have?? The 30" tube on the 5SMc test subject comparing to a (most likely) 24" or less 204 Ruger isn't really a fair comparison...

    6" of barrel with an intense cartridge could surely make up 150fps+...

    You just can't get something for nothing...

    Like the 6BR...the reason we can get it close to equaling the 243 is because the brass allows us to push the crap out of it /ubbthreads/images/graemlins/smile.gif
     
  13. goodgrouper

    goodgrouper Well-Known Member

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    [ QUOTE ]
    You just can't get something for nothing...


    [/ QUOTE ]

    Wasn't that the name of a Rush tune...?

    Like I said, I don't believe anything until I can put it over my Oehler. These speeds are just what he told me he was getting and nothing more. I think the 204 is a pretty fast little cartridge and surely uses less powder and is typically chambered in much shorter barrels as you said.
     
  14. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    GG,

    I have read many of McPhersons test results on this round and to be honest, in nearly every one, top accuracy was several hundred fps off what was possible with this chamberings max output levels.

    Not sure why but in nearly every case that was so. Unfortunately, the extreme velocity is generally the point pounded on and then as you read more about the round you find out accuracy really suffers at extreme velocity. Not only that, at the accuracy level he was reporting in the two tests I read, he was using an accuracy load that was identical to most 204 loads......

    I am with you, not sold on it.

    I will admit that he may well have had to much twist rate in those barrels for the speed they were pushing to and that would explain the poor accuracy at higher speeds and fine accuracy at lower velocity but one would think this would have been anticipated and planned for????

    Anyway, its a neat idea but like you, I have not decided to totally believe the idea.

    Its really nothing new, its basically 1/2 a weatherby shoulder and we all know that the freebore on those rounds generate more velocity then the actual shoulder design ever did.

    Just my opinion. Always neat to see something new come out and will be watching this more and more but not sold on the idea yet.

    Kirby Allen(50)