I was just perusing a few of the lightweight build threads and something occurred to me. It seems like one of the biggest weight savings is switching to a .625" diameter barrel. For people doing things like buying low-mass carriers and even using polymer lowers (blech) would it be possible to shave a few ounces by fluting a lightweight barrel? How much weight savings could be achieved?
Before I get a bunch of “why would you want to do that” and “do more pushups” responses let me say that I’m not planning on doing this myself, I like my CL Noveske barrels just fine. It’s more of an academic question, and I already do a shitload of pushups.
I’m not sure you would have enough material or thickness in the barrel to even flute. Or, the fluting would be so shallow that you wouldn’t lose much weight off the barrel. One other consideration is that at some point, the barrel would lose a decent amount of ridgidity. Any which way, I’d say it’s not feasible.
Don’t know about fluting, but KAC dimpled the lightweight profile barrel on the Magpul Dynamics edition of the SR15E3. I believe the barrel was dimpled forward of the gasblock only. Not sure how much weight this ultimately saved, but it is possible to further remove material from a lightweight barrel to save a bit more weight.
Thanks for the responses. I understand that any sort of fluting or dimpling would reduce wall thickness but how much wall thickness is necessary? What if you just altered the forward half? I’m not an engineer but it seems that if a .625 barrel can take the pressure 4" from the muzzle then you would need less than .625 at 8". Of course there’s always the danger of making a barrel so thin that it becomes fragile but my understanding is that fluting only marginally reduces a barrels’ stiffness.
Having recently bought a BCM lightweight midlength (nominally .625") I was very surprised at how LITTLE weight savings there was in comparison to the made-by-committee government profile barrels I’m used to. After that purchase I found the list of barrel weights below for one maker, showing only a 2.4oz savings going from a govt profile 16" midlength to a lightweight profile.
Having made some heavy pigs of AR15s and then asking how I got there, I think the key areas for weight savings - or really to avoid adding weight - are:
-buttstock (Magpul UBR is great but it’s almost a pound heavier than some other options)
-heavy quadrails (nearly all of them except Daniel Defense and apparently Centurion)
-heavy optics (all of them except the Aimpoint micro and smaller ACOGs, and don’t forget the weight of the mount)
-rail accessories you don’t actually need (btw, rail covers can add up to 4+ oz on longer rails)
a fluted barrel will be less stiff than a unfluted barrel of the same weight You can’t remove material and increase stiffness. Your barrel is stiffer now then it will be after it is fluted.
No, a fluted barrel of the same weight will be stiffer than an unfluted barrel of the same weight since the fluted barrel will have a larger diameter. Naturally, for barrels with the same diameter the unfluted is stiffer.
I wouldn’t suggest dips either since this is primarily for chest and triceps.
I’d recommend standing military presses for the delts.
Dave Tate
