Gibbs Posted August 24, 2014 Report Share Posted August 24, 2014 I love to hear opinions and thoughts. I have read and heard about ways to dampen or change the barrel harmonics of rifles. What I understand is that there is a sound wave that travels at the speed of sound through metal when the cartridge is fired. VERY fast, much much faster than through air. In fact it is said that this shock wave hits the end of the barrel, heads back to the breech, then back again to the end of the barrel several times before the bullet has had a chance to exit the muzzle end. I have read that it is important that the shock wave or "harmonics" have not coincided with the exit of the bullet at the muzzle end. I've even Seen a system on one rifle, in video, BOSS (Browning's paten on Ballistic Optimizing Shooting System ) *google search BOSS barrel tuner, and you will see this. You tube video even has a clip on it. What's the opinion of the .308 crowd? There is only a short distance between the gas block and the end of the barrel and was not sure that harmonic dampening can have a benefit in that short distance. Quote Link to comment Share on other sites More sharing options...
jtallen83 Posted August 24, 2014 Report Share Posted August 24, 2014 When I was a kid Brownell's sold these rubber ball looking things that you slid onto the barrel and then adjusted the location to "tune" the harmonics. I was pretty sure it was a gimmick but after researching the ladder system for tuning reloads for a rifle I might be swayed. The barrel moves up and down during the vibration, the idea is to get the bullet to exit the muzzle at the top or bottom of the wave where it sits still the longest. Here is some reading on it; https://www.google.com/webhp?sourceid=chrome-instant&rlz=1C1SFXN_enUS501US504&ion=1&espv=2&ie=UTF-8#q=reloading%20ladder%20method Quote Link to comment Share on other sites More sharing options...
planeflyer21 Posted August 24, 2014 Report Share Posted August 24, 2014 This QUE Adjustable Muzzle Brake was out lloooonnng before Browning introduced the BOSS. Imitation is the sincerest form of flattery. http://www.brownells.com/rifle-parts/muzzle-devices/compensators-amp-muzzle-brakes/adjustable-muzzle-brake-prod1540.aspx?psize=96 Quote Link to comment Share on other sites More sharing options...
shepp Posted August 24, 2014 Report Share Posted August 24, 2014 (edited) When I was a kid Brownell's sold these rubber ball looking things that you slid onto the barrel and then adjusted the location to "tune" the harmonics. I was pretty sure it was a gimmick but after researching the ladder system for tuning reloads for a rifle I might be swayed. The barrel moves up and down during the vibration, the idea is to get the bullet to exit the muzzle at the top or bottom of the wave where it sits still the longest. Here is some reading on it;https://www.google.com/webhp?sourceid=chrome-instant&rlz=1C1SFXN_enUS501US504&ion=1&espv=2&ie=UTF-8#q=reloading%20ladder%20method I was somewhere in the past month that had theses and I thought WTF IS THAT?!?! Question answered Edited August 24, 2014 by shepp Quote Link to comment Share on other sites More sharing options...
98Z5V Posted August 24, 2014 Report Share Posted August 24, 2014 Tuning barrel harmonics with balls and clamp-on weights has been around for a long time. If you're not making money shooting in competitions, then you're chasing ghosts. You CAN dial it in, but for what purpose? Military snipers aren't out there adjusting a ball on their barrel, and that's "defending lives." Where's Owl right now, to give the Sniper Feedback? Quote Link to comment Share on other sites More sharing options...
planeflyer21 Posted August 24, 2014 Report Share Posted August 24, 2014 Where's Owl right now, to give the Sniper Feedback? Who? Quote Link to comment Share on other sites More sharing options...
unforgiven Posted August 24, 2014 Report Share Posted August 24, 2014 Whooooo..whoooooooooooo. He's with the rest of F troop on special assignmet. Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted August 24, 2014 Report Share Posted August 24, 2014 I've heard of these dampeners before. I always wondered, "why?" I guess I don't make enough extreme long range shots... Quote Link to comment Share on other sites More sharing options...
Boerboel guy Posted August 24, 2014 Report Share Posted August 24, 2014 I may consider something like this if I was shooting bench rest type comps, but for anything else it's just extra weight to carry, extra variables to screw up, and extra crap worries floating around in my head where only stillness should be. Quote Link to comment Share on other sites More sharing options...
Gibbs Posted August 24, 2014 Author Report Share Posted August 24, 2014 Interesting in my search I found a thread in a "Machinist Forum" site that even they are aware of barrel harmonics and nodes and were discussing "ringing a barrel" to determine where to cut the barrel. http://www.practicalmachinist.com/vb/gunsmithing/ringing-barrel-127452/ I was thinking that one could "tune" a barrel for various handloads that using it might tame the barrel harmonics and vibration a bit. As 98Z5V had pointed out, military snipers use weapons that are not "accurized" with tuners, per se, but I am betting that they do a lot of work with handloads to figures out what works the best in what barrel/rifle. For hand loaders, we are aware of barrel harmonics and what a good load will do for accuracy or lack thereof. Trick is to get the bullet out the barrel at the right time when the barrel has the least amount of any whip/movement at the crown, or at least make sure the load leave the muzzle when the barrel is in the same position of movement shot after shot. I do have a small aluminum clamp in my box of stuff that I think came from a 22 scope or laser set up that has 2 allen head bolts and fits around the .308 barrel. I have a 100 yard range in my back yard (live in the country) which is open 24/7 and I made up some rounds of the same bullet, powder, primer, brass, etc and can take a look at with and without and see if there is some benefit. The ONLY benefit, would be if you could dial the barrel into your bullet weight and small variances in powder charge, seating depth, would be negated. If that can't happen, then it's just another variable that has to be set "right" for it to work as it should. I'll try out some targets and loads,even though this is not a BOSS type of system, it might give the barrel some dampening of sorts in an experiment. Other thought is the actual flash hider on the the end of my barrel. Would it shoot differently without it? I would think it might since it adds weight, and torque on the threads at near the barrel crown. Now I wonder what would happen if the flash suppressor were further out on the barrel by using 2 or 3 crush washers (to keep alignment correct for the non slot end being at the bottom)? Quote Link to comment Share on other sites More sharing options...
Gibbs Posted August 24, 2014 Author Report Share Posted August 24, 2014 I did stumble across a link kind of on the same thought as above about the movement of the flash suppressor, of a bench rest rifle using a tuner on the end of the barrel. Seems like a lot of scientifc analysis and somewhat interesting views in 3D of how barrels move during firing, according to frequencies. link -> http://www.varmintal.com/aeste.htm Quote Link to comment Share on other sites More sharing options...
shepp Posted August 24, 2014 Report Share Posted August 24, 2014 Maybe some tuning forks would help?? Quote Link to comment Share on other sites More sharing options...
Matt.Cross Posted August 24, 2014 Report Share Posted August 24, 2014 Are we still talking about the large ARs here? My gas block serves as a perfect harmonic damper, what else is needed? Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted August 24, 2014 Report Share Posted August 24, 2014 That's it! I'm putting a whisker biscuit on my rifle, just because of this thread... and I'm going to take copious pictures of it and mass text them to a bunch of you. Quote Link to comment Share on other sites More sharing options...
Rsquared Posted August 24, 2014 Report Share Posted August 24, 2014 You don't have the balls. <laughs> Quote Link to comment Share on other sites More sharing options...
Gibbs Posted August 24, 2014 Author Report Share Posted August 24, 2014 That's it! I'm putting a whisker biscuit on my rifle, just because of this thread... and I'm going to take copious pictures of it and mass text them to a bunch of you. :LOL: Quote Link to comment Share on other sites More sharing options...
98Z5V Posted August 24, 2014 Report Share Posted August 24, 2014 If such a device really had a great added value, and did what people say it does, then you'd find the product in David Tubb's online store. It's not there. Likewise, he would have it on the Tubb 2000 rifle. That kinda answers it for ya, right there. Quote Link to comment Share on other sites More sharing options...
unforgiven Posted August 24, 2014 Report Share Posted August 24, 2014 Yup.. :yup: Quote Link to comment Share on other sites More sharing options...
Gibbs Posted August 24, 2014 Author Report Share Posted August 24, 2014 This has been a great thead, if only for the fact of learning about David Tubb and his site. Thanks 98Z5V for the valuable info and thoughts. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted August 24, 2014 Report Share Posted August 24, 2014 I just put my comment in there after searching what he offered for a barrel donut. No kidding, if it really changed round impact in a dramatic way, he'd offer it for sale and use it on his flagship target rifle. Quote Link to comment Share on other sites More sharing options...
Gibbs Posted August 24, 2014 Author Report Share Posted August 24, 2014 (edited) Well, he does have a tune-able muzzle brake for the 2000. http://www.davidtubb.com/catalog/view/theme/davidtubb/pdf/product_information/T2K_brake_sheet.pdf It states it has an optional lock nut to tune vibrational nodes. Cost is $119.00 and product description is here: http://www.davidtubb.com/muzzlebrake?search=Brake&description=true Thead is not for a AR .308 though, it is 3/4 - 28 pitch thread. (You'd think I'd learn to spell check before posting) LOL No, I don't think donuts are the answer, nor are rubber rings. What Browning patented and what that one guy has at his site is more on the idea of muzzle devices that are fine threaded for minute changes in the very end of the barrel, even on David Tubb's "Tubb 2000 Custom Muzzle Brake". If you had a 5/8 -24 locknut (thin) one could do something similar with the flash suppressor on the end of the AR 308 rifles. This you tube video of David Tubb talks about tuning your rifle to find a sweet spot with this brake and advancing it out or in a bit for that sweet spot. https://www.youtube.com/watch?v=dqvVHS6T_sM If one were well versed in engineering and metallurgy, you might create harmonics in a rifle barrel and say "Cut this one to 16" + 0.225" and hit the magic spot of node vibration for that particular barrel. But, they are mass produced things (barrels) and as such they are generally cut at 16 1/4" just to make sure it is past the 16" minimum and then the barrel will find it's niche with certain bullets/powder/primer/cases and handloaded to where the ammo is in tune to the barrel rather than the barrel in tune to the ammo. Edited August 25, 2014 by Gibbs Quote Link to comment Share on other sites More sharing options...
washguy Posted August 25, 2014 Report Share Posted August 25, 2014 (edited) My bullet is going so fast it cant remember where it came from when it hits steel at 500....although the groups could be tighter hmmmmm.....what to do? :) Wash subject for harmonics test: 6.8spc2.....5R .....16" full twist fluted one of a kind barrel...well maybe three of a kind........ Edited August 25, 2014 by washguy Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted August 25, 2014 Report Share Posted August 25, 2014 Hahaha hahaha Quote Link to comment Share on other sites More sharing options...
98Z5V Posted August 25, 2014 Report Share Posted August 25, 2014 Gibbs, you've shown that you can shoot well enough to test something like this out. Have at it. Pick up something to tune a barrel, test that thing out, makes your groups, and let us know how it does or doesn't. For you, with the way you shoot, that's easy. Quote Link to comment Share on other sites More sharing options...
planeflyer21 Posted August 25, 2014 Report Share Posted August 25, 2014 My bullet is going so fast it cant remember where it came from when it hits steel at 500....although the groups could be tighter hmmmmm.....what to do? :) Wash subject for harmonics test: 6.8spc2.....5R .....16" full twist fluted one of a kind barrel...well maybe three of a kind........ Dude! Is that the limited edition Aloha Snackbar Chancla?! Quote Link to comment Share on other sites More sharing options...
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