RDQ: Are Carbon Fiber free float hand guards much lighter than vented aluminum?

[Captain33036]

Hi Everyone

Sorry, if this has been asked and answered before, I really cannot find much QUANTITATIVE information.

I have been wondering whether or not it would be worth it to change out my present vented aluminum free float handguard with a carbon fiber one. The only reason I would do this could be to lighten it up. It is standard length.

It would have to be close to a half pound lighter (6-8oz) to really be worth it, I would think.

When I look at the specs of the various handguards out there, the carbon fiber ones seem to be 6-10 oz in weight, whereas the standard, vented aluminum ones are 8-14 oz, or so.

Is there really this little difference? Does not seem worth the expense.

Thanks

John

 

[dprice3844444]

keep what ya got while it works

 

[rcmodel]

I think the major advantage would be they don't get as hot to hang onto in the sun, or after extensive shooting.

rc

 

[Captain33036]

PS - entire upper weighs about 4 lbs, including bcg

Barrel is a 16" govt profile DD, 5.56

I do not want to change anything else right now, except ...perhaps the handguard. But....not sure how much weight that would save. Does not really look like much.

Thanks

J

 

[Captain33036]

I lucked into a nice gun. Entire gun is fantastic. DD barrel. Amazing accuracy. I really do not want to change anything, except the handguard and only if that would shave 6-8 oz.

Thanks.

 

[taliv]

it is kind of interesting. the key seems to be the barrel nut. i have a clark customs carbon fiber handguard. it has an aluminum barrel nut and is extremely light. the PRI carbon fiber handguards seem to be heavier than most aluminum ones. a lot of rails/handguards like the magpul stuff use the relatively heavy standard barrel nut, so even though they are light, the use of the standard nut makes it pretty heavy.

i just bought bravo co's 13.4" KMR rail which weighs 7.7 oz to add to this gun, which will bring it to 5 lb 2 oz. hope to have it completed this time next week. (This is shaping up to be the ugliest rifle I've ever built...)

 

[BCRider]

think the major advantage would be they don't get as hot to hang onto in the sun, or after extensive shooting.

It can depend on the finish used on the carbon fiber. Back when I was windsurfing I had two carbon masts. One with the deep shiny finish would get burning hot in the sun in only a few minutes. The other with a dull matt sort of finish got warm but not hot. It may have been the matt clear coat or it may have been something else at work. No way to find out.

Anywho..... there's no guarantee that a carbon fore gaurd won't be just as hot as a matt black aluminium guard. The one thing for sure is that any heat will be from the sun and not from the barrel.

 

[Ibmikey]

You are the one who must decide as the variables are so great, choose a carbon fiber guard and compare it with the weight of your rail and nut, i often use the MI Gen 2SS rail which is light and slender. The ALG Ergonomic rail is slim, light and uses an aluminum nut, nice set up. In any event your saving of a few ounces by changing will cost you a couple of C notes.

 

[pintler]

FWIW, the AP Custom Standard carbine handguard weighs 3.8 oz. A moment's googling found one for $115 (I didn't check shipping).

 

[Captain33036]

Hi Guys

Thanks for the help. That is the thing. Even if a CF handguard is 4oz, if an aluminum one is 10 oz, that 6oz is not worth $115 to me.

So...will probably stick with what I have. Just find it interesting that CF handguard were touted so much and have a premium price and yet do not even save you a half a lb.

I think the barrel nut is most of the weight. A vented Al forearm does not seem to weigh all that much.

Maybe I can do this in my head. Al has a density of 2.7g/cm3
An Al forearm may be 9 in long, 2 in diameter, pretty thin and slotted. So...
23cm x 7.5cm x 0.5cm = 172cm3
172cm3 x 0.85 = 146.2cm3
146cm3 x 2.7g/cm3 = 394.2g
394g = 13.9 oz

That is pretty light, less than a pound.

And I think they are lighter than that. I think....and here is where I need your input, I have seen weights listed at 0.5- 0.6 lbs, which would be 8-10oz.
Thanks
J

 

[taliv]

the 7.7 oz KMR rail i mentioned is magnesium/aluminum, not pure Aluminum

 

[Captain33036]

So, even lighter than pure Al. I suspect a number of Al foreguards are lighter, cheaper alloys. So...lighter...which is fine.

Which brings me to my original point...it really does not seem that there is a significant weight savings with CF handguards.

 

[Arizona_Mike]

I think the KMR rails are a game changer. Ever so slightly heavier than a carbon fiber tube when the barrel nut is taken into account and much more functional.

Mike

 

[Bobson]

When I look at the specs of the various handguards out there, the carbon fiber ones seem to be 6-10 oz in weight, whereas the standard, vented aluminum ones are 8-14 oz, or so.

Is there really this little difference? Does not seem worth the expense.

If your current setup is on the heavy side of your "typical" findings (14 oz), and you get a CF one on the lighter side of average (~6 oz), you drop the half pound of weight you're looking for.

OTOH, if your current vented aluminum is already the lightest one in its class, and you buy the heaviest CF one available to replace it, you could easily add weight to the rifle overall. So sure, it could be worth it, but it could also be negligible, or even detrimental.

 

[JustinJ]

Every ounce can count, especially forward of the receiver. However, lighter front means more muzzle climb and recoil as well. If saving a few ounces is worth it or not depends on the gun's purpose, or potential purpose.

 

[Sam1911]

Just FYI:

The new Midwest Industries light weight railed tubes are pretty phenominally light.

8.2 oz for the 12" rail, and 9.3 oz for the 15" one. I have the 15" rail on the rifle I'm building. And a BCM Gunfighter comp to keep the muzzle under control.

http://www.midwestindustriesinc.com/index.cfm?fuseaction=category.display&category_ID=1266

And those weights aren't for a plain fiber tube, they're for an aluminum tube with sling mount points, rail sections, and M-LOK or KeyMOD mounting holes throughout.

 

[Arizona_Mike]

Just FYI:

The new Midwest Industries light weight railed tubes are pretty phenominally light.

8.2 oz for the 12" rail, and 9.3 oz for the 15" one. I have the 15" rail on the rifle I'm building.

http://www.midwestindustriesinc.com/index.cfm?fuseaction=category.display&category_ID=1266

And those weights aren't for a plain fiber tube, they're for an aluminum tube with sling mount points, rail sections, and M-LOK or KeyMOD mounting holes throughout. And a BCM Gunfighter comp to keep the muzzle under control.

That is nice. The 15" is only 1.2oz heavier than the KMR15. Hopefully it is a market trend.

Mike

 

[kbiggun]

Depends onot what your using it for

 

[kbiggun]

My stag with scope Samson quad rail isn't light but I do alot of target shooting,coyote,prairie dog hunting,don't mind the weight,if anything it helps me steady my shot when not using bipod.

 

[locotonyf]

I have all Magpul furniture on my Stag Model 8. It's very comfortable to hang on to and deadly accurate. I say don't overthink it and go with your own preference. When it comes to your rifle, you've only yourself to please.

 

[Captain33036]

Trying to post a pic, but photobucket not cooperating today.

At any rate, measured the gun with a fish scale (all I have). 7 lbs total (without scope). Entire upper is about 4 lbs.

DD govt profile barrel is pretty heavy, must be close to 3 lbs. So....upper receiver, bolt, barrel nut and foreguard about a pound.

Which would mean the foreguard is pretty light. And not much weight savings can be had.

Might get a real scale and measure components, just to contribute. Really appreciate the info.

Someone posted...go with the gun you like....good advice. Like this gun as is, accuracy is amazing.

Added:

Photobucket still has a bug, but was able to get more info and do some measuring.

Entire gun weights 6lbs 14 oz

Upper weighs just 4 lbs.


The DD 16" govt profile barrel is 1.7lbs or 1 lb 11 oz

BCG weighs 11 oz

So, barrel and BCG together are 2lbs 6 oz.

That leaves 1lb 10oz for the upper receiver, flashider, barrel nut and floating handguard.

Not convenient to take the hardguard off right now, but, from the above, does not look as though there can be any significant weight savings even for $200+ in replacement parts.


Thanks

 

[Captain33036]