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I don't know. I didn't notice that. I had a good email conversation with the owner, prior to ordering mine. I just emailed him your question. I'll let you know what he says.
His reply:
Sorry for taking so long to get to your email.

I guess someone was eventually going to ask the right question...haha. So what they're seeing is basically the patent pending construction of the handguard, and the reason why it's lighter than anything else out right now. It's commonly referred to as sandwich panel construction. I'm an aerospace engineer with composites experience so I've seen it a good bit.

These guys did a pretty good brief description of what it is:
Buy Composite Sandwich Panels | Rock West Composites

This is a little more in depth explanation and really well written:
Why You Should Be Using Sandwich Panels aircraft interiors and Formula 1 cars are so stiff and light

They only say aircraft interiors in the second article but it's also used on structural parts that will take bird strikes.

Anyone who's worked in composites will probably appreciate the difficulty and expense in making a tubular shaped sandwich laminate. The fact that it's used on formula one cars should say a lot. They're definitely on the cutting edge of composites technology.

I hope that answers your question.
 

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Not sure what you mean. AWB? Civil war?
Well, we know the left is pushing for the one world government our whole lives. I am 48. Now, they are getting close.

Matthew 24:20
And pray that your flight may not be in winter or on the Sabbath.
 

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Discussion Starter · #44 ·
His reply:
Sorry for taking so long to get to your email.

I guess someone was eventually going to ask the right question...haha. So what they're seeing is basically the patent pending construction of the handguard, and the reason why it's lighter than anything else out right now. It's commonly referred to as sandwich panel construction. I'm an aerospace engineer with composites experience so I've seen it a good bit.

These guys did a pretty good brief description of what it is:
Buy Composite Sandwich Panels | Rock West Composites

This is a little more in depth explanation and really well written:
Why You Should Be Using Sandwich Panels aircraft interiors and Formula 1 cars are so stiff and light

They only say aircraft interiors in the second article but it's also used on structural parts that will take bird strikes.

Anyone who's worked in composites will probably appreciate the difficulty and expense in making a tubular shaped sandwich laminate. The fact that it's used on formula one cars should say a lot. They're definitely on the cutting edge of composites technology.

I hope that answers your question.
I had a feeling that's what it was. I kinda doubt it's strength benefits vs carbon fiber of equivalent volume. My coda handguard has thinner walls (significantly thinner) and seems stronger than the JAG, even though it's only 0.4oz heavier (both are 13.5"). When I try to squeeze the jag together I hear cracking. No such thing with the coda. Maybe the cracking sounds aren't a problem though. But there is the problem of bolting things on, like MLOK accessories. I hear the crunching when I tighten the screw. Nevetheless, I didn't tighten it too tight, all is well and I'm happy with it. Would like to see a torture test of it, comparison with other CF handguard etc.
 

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My coda handguard has thinner walls (significantly thinner) and seems stronger than the JAG, even though it's only 0.4oz heavier (both are 13.5"). Would like to see a torture test of it, comparison with other CF handguard etc.
Oh, I see that the Jag is 2.8oz lighter, since it's is 4.1oz and the Coda is 6.9. Or are you comparing just the carbon tubes without barrel nuts and hardware?
Would like to see a torture test of it, comparison with other CF handguard etc.
Yeah, that would tell the tale. I'd like to see that. 3 of the top CF HGs will be $1000 though. Who can we encourage to get all of those just to destroy them? MrGunsnGear perhaps?
 

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Discussion Starter · #46 ·
Oh, I see that the Jag is 2.8oz lighter, since it's is 4.1oz and the Coda is 6.9. Or are you comparing just the carbon tubes without barrel nuts and hardware?

Yeah, that would tell the tale. I'd like to see that. 3 of the top CF HGs will be $1000 though. Who can we encourage to get all of those just to destroy them? MrGunsnGear perhaps?
Yeah. I was comparing just the tubes. The coda uses barrel nut + trunnion, jag uses just a barrel nut. And it's a bigass trunnion lol
 

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When I bought both of mine, I made sure they were a heavy barrel. And RRA does the full length heavy, not just after the hand guards. With my basic M4 clone, they are 7.5 lbs, which is closer to the A2-A4 weight.
 

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Mine too. I’ve got ARP and Bison barrels, and both are extremely accurate.
Good to hear. I probably should have invested in tools to swap out ar barrels myself. Only thing left for me to learn on ar platform assembly wise. in 556 i have two larue barrels, the 18” is moa, the 16” not so much and both purchased around the same time. My 18” noveske 2.5lb barrel however gets most of the use. my tikka, ruger and lilja barrels in 6.5 all sub moa with most ammo.
 

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The 16" ARP 3R I had and 16" DD 5R I now have were / both very accurate. Both are MOA or better with several factory loads and Druid Hill custom loads. I really like JP's receiver vice clamps for swapping barrels. It does an excellent job of proper holding and supporting the upper receiver. Using a crows foot and calibrated torque wrench, it's not a difficult process at all.
 

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Handguards. I paired a heavy S2W profile 16" DD barrel clocking in at a hefty 36.9oz with a 5.8oz Magnesium Alloy handguard (15", that weight includes barrel nut and screws). A typical 6061 T6 15" handguard (MLok) weighs 15oz with barrel nut. Something like the Daniels Defense RIS II non-FSP 12.2" in picatinny used on the Block II M4A1's is a whopping 17.7oz. The 14.5" socom 5.56 barrel weighs 30 oz.

Do the math:

My Setup
36.9 + 5.8 = 42.7oz

ARP 16" Scout + 15" M-Lok Handguard (6061 T4, something like the Geissele SMR 13.5" or run of the mill 15")
28.6oz + 15oz = 43.6oz

ARP 16" Scout / Bison 16" Recon + JL Billet Mag-Alloy 15"
28.6oz + 6.5oz = 35.1oz

ARP 16" Scout / Bison 16" Recon + JL Billet Mag-Alloy 13"
28.6oz + 5.8oz = 34.4oz
 

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Good info there. I went a similar route:

ARP 16" 3R-11 Scout 28.6 oz + Jag 13.5" Ultralight Carbon Fiber 4.1 oz = 32.7 oz total.

Love that carbon fiber too. It doesn't get hot to the touch, or feel cold in the winter. Amazingly solid for the weight.
I almost went carbon fiber, but decided not to for one reason. Abrasion. Once you loose the protective coating, it's exposed to UV light and will start to break down.

Carbon fiber is an awesome material, but my use cases are pretty hard on the rifle, typically half the gun is exposed to bare metal after just a year or so of use due to being knocked about, dropped, scraped against gravel etc.

I was a concerned that I would run into that issue at some point due to wear, but maybe I'm just paranoid. If I build a new system, maybe I'll give it a try and see how it holds up. But I think that would be a really good option for hunting rigs or home defense.
 

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I almost went carbon fiber, but decided not to for one reason. Abrasion. Once you loose the protective coating, it's ...
That's good insight. I hadn't thought of that. I might have to keep a bottle of clear fingernail polish around to seal up scratches. You should try out a CF handguard and see if it does hold up for you though. I'd be interested to know.
I haven't heard of any CF parts breaking down like that, but they are fairly new and not in use by the military, so I'd guess the folks using them are like me and not using them very hard.
 

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One of the reasons I chose magnesium alloy is that it's highly corrosion resistant but 33% lighter than 6061. AZ61A is about 13% less yield strength than 6061-T6, but that's pretty close. ZK60A magnesium alloy is actually 20% stronger tensile strength than 6061-T6 but the same density as AZ61A. I've been looking for one made in ZK60A but have not found any. I think that would be the ultimate balance between weight vs. strength as it's as light as what I have now but 20% greater material strength than 6061-T6.
 
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