Pac-Nor POLYGONAL rifling anyone?????

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by mindcrime, Jan 5, 2006.

  1. mindcrime

    mindcrime Well-Known Member

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    I noticed that Pac-Nor is now offering POLYGONAL rifling: SEE HERE./ubbthreads/images/graemlins/shocked.gif

    I know that the Confederates used it in their Whitworth Sniper Rifles and their breach-loading Whitworth cannons, and those "guns" were historically more accurate and out ranged ANY rifle or cannon used during the "War of Northern Aggression." /ubbthreads/images/graemlins/laugh.gif

    I also know that Heckler & Koch has used this design for years with success in their entire line, including the PSG-1 Sniper rifle. /ubbthreads/images/graemlins/cool.gif

    "Supposedly" it offers less bullet deformation AND less fouling. Does anyone have any experience with this style of rifling, or any opinions to offer????? /ubbthreads/images/graemlins/cool.gif
     
  2. lastoftheline

    lastoftheline Member

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    accuracy is great.... i have an hk usp tac and a g36 clone and they are both very accurate....

    now this may be just because of the manufacturer and/or the barrel design...

    as for cleaning -- 5 minutes...10 minutes if i am tired. the rifling doenst have any lands and grooves in the traditional sense, so the bullet doesnt scrape along any rifling edges. It is just passed through the altered polygonal barrel.

    with no scraping, there is no copper fouling. so cleanup is a breeze. Barrel wear is almost nil... i have put about 2k rds through my tac with no loss of accuracy or barrel wear (as seen through the finish condition).

    There is a little copper fouling in the 36 though. but not as much as through my other rifles (mauser w/ standard bore rifling). an old g3 i had was the same way. the copper is light and easy to clean up.

    hope this helps.
     

  3. mindcrime

    mindcrime Well-Known Member

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    Thanks for the report! I found THIS ARTICLE on the PSG-1, and they noted:

    [ QUOTE ]
    the PSG1 was designed to meet specifications that required a minimum barrel life of 10,000 rounds. In point of fact, in-house shooting tests by HK ballistic technicians and engineers have produced PSG1s that have exceeded 20,000 rounds without noticeable degradation in accuracy.

    [/ QUOTE ]

    Sounds like barrel life may be longer with Polygonal rifling vs. conventional lands and grooves as well?!? /ubbthreads/images/graemlins/cool.gif
     
  4. gonehuntingagain

    gonehuntingagain Well-Known Member

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    I'm sure someone will correct me if I'm wrong, but as far as I know, you are supposed to get the same velocity with a shorter barrel vs. conventional barrels. I'm not sure what the correlation is (like a 26" poly vs a 28" regular bbl).

    I think one of our moderators has some experience with polygonal rifled barrels, maybe we can get him to chime in? /ubbthreads/images/graemlins/wink.gif
     
  5. royinidaho

    royinidaho Writers Guild

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    [ QUOTE ]
    Thanks for the report! I found THIS ARTICLE on the PSG-1, and they noted:

    [ QUOTE ]
    the PSG1 was designed to meet specifications that required a minimum barrel life of 10,000 rounds. In point of fact, in-house shooting tests by HK ballistic technicians and engineers have produced PSG1s that have exceeded 20,000 rounds without noticeable degradation in accuracy.

    [/ QUOTE ]


    When I read of the HK getting 1/4 MOA shooting a clip full in semi-auto @ 100 meters is when I dumped 3 40Xs and 1 Hart barrelled/Hart Sleeved REM 700 and never looked back.

    If they made one in something bigger than an a 7.62 I'd get it!!!
     
  6. EddieHarren

    EddieHarren Well-Known Member

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    Gary Schneider has been making them for years. Before that McMillan made them.
     
  7. Centre Punch

    Centre Punch Well-Known Member

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    Hi Guys i have a question about polygonal rifling which i hope some of you will be able to answer.

    Firstly the Witworth barrel had a hexagonal bore and shot a tightly fitting hexagonal bullet to achieve its exceptional accuracy.
    A conventional cylindrical bullet could be shot using this rifling, as long it was tightly patched to seal the bore but this way accuracy was mediocre.

    I understand that polygonal rifling uses the 5 sides of the polygon to spin the bullet, therefore is the bore of the the polygonal rifled barrel smaller then bullet diameter? and does it swage down the bullet to take on the polygonal form in order to seal the barrel?

    Alternatively, are the sides of the bore the same diameter as the bullet and pressure bumps up the bullet to seal the bore of the barrel? Thanks.

    Ian.
     
  8. mindcrime

    mindcrime Well-Known Member

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    [ QUOTE ]
    When I read of the HK getting 1/4 MOA shooting a clip full in semi-auto @ 100 meters is when I dumped 3 40Xs and 1 Hart barrelled/Hart Sleeved REM 700 and never looked back.

    If they made one in something bigger than an a 7.62 I'd get it!!!

    [/ QUOTE ]

    So I assume that you like your H&K?!? /ubbthreads/images/graemlins/wink.gif
     
  9. mindcrime

    mindcrime Well-Known Member

    Messages:
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    [ QUOTE ]
    Hi Guys i have a question about polygonal rifling which i hope some of you will be able to answer.

    Firstly the Witworth barrel had a hexagonal bore and shot a tightly fitting hexagonal bullet to achieve its exceptional accuracy.
    A conventional cylindrical bullet could be shot using this rifling, as long it was tightly patched to seal the bore but this way accuracy was mediocre.

    I understand that polygonal rifling uses the 5 sides of the polygon to spin the bullet, therefore is the bore of the the polygonal rifled barrel smaller then bullet diameter? and does it swage down the bullet to take on the polygonal form in order to seal the barrel?

    Alternatively, are the sides of the bore the same diameter as the bullet and pressure bumps up the bullet to seal the bore of the barrel? Thanks.

    Ian.

    [/ QUOTE ]

    Ian, I'm proud of you!!! /ubbthreads/images/graemlins/laugh.gif You know your cannon; either that or you looked it up on the net! /ubbthreads/images/graemlins/smirk.gif Here's what a 12 lb. Whitworth solid bolt looks like .....And here is what the 12 lb. breech loading Whitworth cannon itself looked like. While you are totally correct about the projectiles having to be "poly'd" themselves, the Whitworth cannon has VERY AGGRESSIVE AND DEEP rifling relative to its bore size---I tried to find a picture of the muzzle to show you but I only have those pics in my Library, couldn't find them on the Net. I believe that the modern manufacturers are not even close to getting as aggressive as their predecessors. If they did we WOULD have to have a poly-projectile and H&Ks barrels would be highly unsuccessful! /ubbthreads/images/graemlins/blush.gif

    BTW, and JFYI, I am a Life Member of the "Heritage Not Hate" group Sons of Confederate Veterans, and a highly studied "Civil War" artillery enthuasist. /ubbthreads/images/graemlins/cool.gif Thus, "Sic Semper Tyrannus"
     
  10. Centre Punch

    Centre Punch Well-Known Member

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    Mindcrime,
    I do believe that the 12 pounder whitworth had a screw on breech cap and fired its projectile from hexagonal tin or zinc plated charge cases which extremely rare.
    Another British design, the Armstrong rifled field gun saw action as well as the Whitworth but had a convential rifled bore and had a transverse breechblock locked in place by a threaded breech plug.

    I too have an extensive library but i am no expert on any, let alone US civil war artillary unlike your self, but i thought that might impress you. /ubbthreads/images/graemlins/smile.gif

    Back in the late 1980s i had the privalige to shoot a Parker-Hale replica Whitworth rifle loaded with lovingly cast by the owner, .451 cal hexagonal projectiles.
    I seem to remember some difficulty in seating these projectiles properly without deforming the nose.

    I shot this rifle at 600yds on our club range just for the experience of it, after one of my Pistol shooting sessions (i had little interest in rifles in those days), so i didn't take much notice of the guns accuracy and handling.

    Ian.
     
  11. mindcrime

    mindcrime Well-Known Member

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    [ QUOTE ]
    Mindcrime,
    I do believe that the 12 pounder whitworth had a screw on breech cap and fired its projectile from hexagonal tin or zinc plated charge cases which extremely rare.
    Another British design, the Armstrong rifled field gun saw action as well as the Whitworth but had a convential rifled bore and had a transverse breechblock locked in place by a threaded breech plug.

    Ian.

    [/ QUOTE ]

    Well Sir, once again, you HAVE impressed me!!!!! /ubbthreads/images/graemlins/laugh.gif I knew that as well, however the breach seal in the Whitworths often stuck rendering them as muzzle loading cannon. Did you happen to know that the Confederates also had rounds that were to be fired out of the common 12lber Napoleon smooth bore (4.62" bore) that had spring loaded wings that upon exiting the barrel, imparted a spin on the projectile. /ubbthreads/images/graemlins/grin.gif Technology back then was UP AND COMING!!!

    Tell you a SHORT story, then I'll shut up again. Interestingly, I have been "studying" CW Artillery for no less than 6 years, travelling to visit battlefields, photographically documenting different cannon, when at my step grandfather's funeral I met his youngest brother. His brother is in SCV, and he was told of my interest in the War of Northern Agression by other family members. After our introduction, we began talking about the War, I told him of my interest in CW Artillery. He told me of a Confederate artillery unit that started near where my other grandmother lived.......to make a long story short, 11 out of 13 of my Confederate veterans on my mom's side were in Maury Artillery. So to condense, CW Artillery IS in my blood, even before I knew it was!!! /ubbthreads/images/graemlins/shocked.gif

    I am also a study of the Safaris of the early days, too, believe it or not. I have several Safari books in my library as well, and LOVE reading about Fredrick Courtney Selous hunting elephant with his muzzle loading 4 guage and that "cannon" knocking him off his feet when firing at a charging bull. John Taylor is another of my favorites. I also own TWO .416 Rigbys! /ubbthreads/images/graemlins/cool.gif