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Thread: Barrel Harmonics pretty cool video

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    Default Barrel Harmonics pretty cool video

    Interesting video....

    http://i83.photobucket.com/albums/j307/yrualeg1/sigpic787_4gif-2.gif

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    Default Re: Barrel Harmonics pretty cool video

    I have never seen a barrel resonate or flex like that. I was chatting to one of my friends who is a precision shooter (1,000 yd stuff) and we were discussing his custom rifle with bull barrel. He maintaines that barrel resonance in a good quality (well made 21" or 22") hunting rifle is measured in microns.

    When I fisrt joined the army we were issued FN's (Fabrique National) 7,62's and damn these were good even if a bit heavy. Later we were issued (at para bn) folding stock R1's, basically identical to the FN, same bullet, barrel and action but made lighter. This was also a great rifle. We only practiced out to 300m but regularly got 6" groups from the lying position and this is with open sights, I realise that this does not constitute accuracy but it certainly is adequate for what we had in mind, so the rifle is definitley ok.

    I had already left the army when the new issue of rifles came out and we now use what I believe is the R4 (I have never shot one) somewhere aroung a 5,63 or .222 calibre.

    In the real world I would much rather have the firepower to fetch someone out behind a 6" tree. Another factor which I can personally vouch for is the phsychological edge - in a firefight you can hear the very distinctive "crack" of an AK, it has a signature sound all of it's own and when we return fire there is this huge booming report from the 7,62. It made me feel better even if it was just in the mind.

    I understand I must be wrong in my choice or else the military world wide would still be using the old 7,62 but for piece of mind, given the choice, I know which one I would take with me.

    I don't want to get into rambo bullshit war stories, but a friend of mine took an AK through the flesh on his thigh and while in shock and pain was still able to operate, move and generally look after himself. If that round had been from a FN or R1 I suspect he would have been in deep shit. If you get tagged with an FN or R1 you stay tagged.

    In the hunting environment, all things being equal, I opt for the bigger caliber. I'm not for one minute advocating the use a .308 on squirrels. I have heard stories of guys that have dropped the Cape Buffalo with a 30-06, quite possible, but irresponsible. Now watch me get shot down.

    Have you guys always had what I refer to as "baby bullets"?

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    Default Re: Barrel Harmonics pretty cool video

    We have had a 5.56 mm (.223 cal) since the 1960's in our service rifles. Prior to that we had a 7.62 mm in the M14. Before that we had a pair of .30-06's in the M1 Garand and the M1903/M1917. That takes us back to the start of the 20th century. Before that we had .45-70's in the Krag and Springfield variety. Then we start getting into Winchester Repeaters and black powder crap.

    Our machine guns have always been at least .30 cal. Currently (and since the 1960's) we've had a 7.62x54. Though we do also have a light machine gun in 5.56mm made by FN in the M249 SAW.


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    Default Re: Barrel Harmonics pretty cool video

    I've always been a fan of the 7.62x51 round but they're so damned expensive and a quality semi-auto chambered in that round isn't exactly cheap, either.

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    Default Re: Barrel Harmonics pretty cool video

    Quote Originally Posted by bgermain View Post
    I've always been a fan of the 7.62x51 round but they're so damned expensive and a quality semi-auto chambered in that round isn't exactly cheap, either.
    I was contemplating buying an M1A1 Scout the other day but $1,500 was a heart breaker. I could only dream.

    As far as barrel harmonics go,consistency is important. That is why most experienced shooters will tell you to not place your hand on the barrel or change the harmonics because it will change your point of impact. Avoid laying your barrel on a support or barrier during shooting too.

    Heavy barreled guns tend to be more consistent (accurate) as a rule with all other things being equal.

    Good video,cool to see the slow speed photography,you can tell a lot about a weapon when it is slowed down that much.

    I figured out a long time ago that AK's are good for shooting the guy across the street, not the guy on the mountain top across the valley. They are good for short range and should be used as such.
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    Default Re: Barrel Harmonics pretty cool video

    As an Army sniper (Israeli and British doctrine) in the Singapore Armed Forces, I shot a lot of match .308 made by Lapua in Finland (before the factory got burned down - they have since then retooled and make excellent match ammunition).

    That sonic crack is distinct and gets your attention. Shooting the ammunition with a bolt rifle (based on the Swedish Carl Gustaf Mauser match rifles (heavy barreled version) is extremely hard on a guy due to recoil impulse. However, I would rather have the .308 like the DPMS TAC 20 (see picture) or the 7.62 Nato ball fired from the M240, MAG 58 or GPMG (General Purpose Machine Gun), which are different designations for the same gun, than the 5.56 any day.

    I have shot the AK 47 at Ft. Bragg, while serving in the 82nd, but I still preferred my M16A2 because it was more accurate over distance. Given a choice, I would prefer this (see the attached picture) to an M16A2. Given even more leeway I would prefer the M16A2 shooting the Grendel 6.5. Just my opinion on a good compromise between a heavier caliber and longer distance accuracy and how much ammo can be carried.

    Finally, to get to the actually discussion at hand, barrel harmonics occur regardless of the thickness of a rifle barrel. Even the thick match barrels flex and the mechanical system in the M14 contributing further to its strange harmonics, makes the M14 a bitch to keep and maintain as a competition or sniper rifle system. The same thing occurs with the FN SLR or LAR rifles. I'm sure it is because of the short or long stroke piston systems. With the AR design, everything is in line with the barrel and it uses a direct impingment system for recycling the bolt carrier system. All adding to the AR being an inherently more accurate rifle design.

    Everyone thinks that the Mauser was the better bolt action rifle but it was the Lee Enfield rifles that were the secret of British success. The strange harmonics from the receiver and the barrel both worked to make it extremely accurate when properly "moderated" (accurized - I think that the word moderated is correct - I could be wrong), the barrel would whip differently every time and take care of the variations in cartridge manufacture. Moderation I believe made that more consistent and less unpredictable especially when the British Commonwealth went to the 7.62 Nato from the .303. For the longest time Match competitions and military competitions out to 1200 yards would be won using these rifles until the advent of the very thick bolt action receivers and barrels.
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    Last edited by Ricardus; 04-22-2009 at 11:04 AM.
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