View Full Version : Lightweight or not?

04-28-2008, 12:35 PM
Im currently building my first AR and am looking at a couple of 16" Uppers from CMMG and was just wondering if I could get some of your opinions on the different types they offer. I plan on getting either the 16" Mid-Length or the 16" Lightweight Mid-Length. How much lighter is it really? I've read that they "lose" their accuracy once they heat up but also since this is only a Semi, its a non-issue.

Since they are the same price, which one would you get? Heck, would you even recommend the MedCon 16" Middy. Thanks for the input everybody.

04-28-2008, 12:56 PM
i have 2 medcon uppers. the weight wasn't worth me getting a lighter contour barrel. Just like you said, once the barrel heats up, the lighter contour barrel will loose accuracy faster than the heavy barrel. CMMG makes good quality uppers, which ever you choose, you will be happy with it.

04-28-2008, 3:51 PM
Well, unless you are doing a lot of rapid fire, the accuracy is not an issue (for the difference between of med-contour and light-weight BBLs).

The weight between med-contour and light-weight is pretty sensible. If you are carrying your rifle and are walking/moving for a long distance, the weight matters. If you are just shooting from bench, the weight does not matter. I do not have the number of the weight difference. AR15Barrels please chime in.

Basically, all LMT upper halves we've received were all equipped with light-weight barrels. (The MRP/CQB ones are exception.) And they are the same as what our GI Joe/Jane have in the sand box.

04-28-2008, 3:58 PM

Can't resist.....

Actually.... you can drop more weight if you remove the "EOTech + LaRue LT110 mount", and switch the LMT SOPMOD with the Magpul CTR.... that's probably as "lightweight" as you can ever get...

The SOPMOD to CTR is not a lot of reduction tho.

You MAY be further reduce by using a "plastic" handguard as compare to a FF-railed, but that make the whole thing not as NICE.....

04-28-2008, 5:14 PM
I was working on building a super lightweight upper and I purchased a lot of parts and what I found is that this following setup was very light while still being very usable and it gives you a lot of "mission specific" add-on capabilities. It's not a "dead end" KISS setup (I think KISS = BS anyways).

Barrel: Colt M4 14.5"
Muzzle Device: YHM Phantom 5C1 (Perm. Attached)
Gas Block: Vltor Low Profile
Front Sight: KAC Flip Up BUIS (Fluted)
Rail: Daniel Defense 7.0 Lite (0.70 oz lighter than the Colt M4 handguards!)
Upper: Colt M4 upper
BCG: Colt AR15 ("Semi") BCG

This is LESS THAN 1/3 oz heavier than a typical 0.625 Gas Block "lightweight" barrel setup with a A2 FSB (like a Colt 6530 but with a flat top upper) with plastic handguards...

Now add a Aimpoint Micro T-1 on a LaRue LT66X and you have a nice lightweight (and durable) optic or if you don't need to have QD, get the YHM-226 which is a 1/2" riser.

As for the buttstock, the CTR WITH the rubber pad is only 2oz heavier than the standard collapsing buttstock (the current USGI issue one).

My mainline carbines are setup nearly identical to this except they have GG&G FSB's (gas block/flip up front sight the clamp version) which is a little heavier but the barrel, handguard, upper, flash suppressor, etc. are all the same. I have run this full auto and select fire (out of state and on a RR and a RDIAS equipped lower of course) and I use it in all my carbine training courses (high round count in a short amount of time)...I have no issues with accuracy even when the barrel is smoking hot. I seriously doubt more than a handful of Calguners actually run their carbines even remotely close to this level so don't even worry about loosing accuracy to heat.

And personally, I would avoid CMMG because they don't have great QC in my experience. I'm willing to pay a little more and get better stuff.

04-28-2008, 11:43 PM
all LMT upper halves we've received were all equipped with light-weight barrels.

LMT uppers are govt profile barrels.
Lightweight barrels will generally be about 4-6 ounces lighter than a govt profile barrel.
The difference does not sound like much, but it's almost all out in front of the front sight where it makes the most difference in handling.
The profile of a lightweigh barrel and a govt barrel are usually the same behind the FSB.

04-28-2008, 11:44 PM
You MAY be further reduce by using a "plastic" handguard as compare to a FF-railed, but that make the whole thing not as NICE.....

A Daniel Defense M4 7.0 is lighter than standard plastic handguards with a delta ring, barrel nut and handguard cap. ;)