2024 308 Carbine options?

[1168]

Typical AR-15 BCGs are ~11.5 oz; typical AR-10 BCGs are over 19 oz, so close to half a pound of difference. An Aero Precision M5 receiver set is 24.7 oz, while an AP milspec forged receiver set is 15.25 oz (an AP AR-15 billet set is 17.8 oz), so again over a half pound of difference. So that right there is one whole pound. Even barrels do have a different weight between large frame and small frame, even if about the same overall profile; for a Criterion hybrid profile, the .308 Win barrel is consistently close to half a pound heavier than the .223 Wylde in the same length (looking at 16", 18", and 20"). For a 13" Centurion Arms M-LOK CMR, there is a 4.7 oz between the large frame and small frame.

So I think you're looking at 1.5 lb penalty pretty easily if you're trying to like-for-like on the design between a small frame and a large frame, if you're going to do an equal profile barrel rather than equal weight. You could certainly get the lightweight parts instead of the more standard parts on the large frame and bring it back down to weight, if you really wanted, e.g., V7 has a ~6.25 lb .308 Win 14.5" gasser, but then a corresponding V7 14.5" small frame is ~4.5 lb.

Thanks.

Weighing an almost complete 13.5” 5.56* gun (no optic, sling, or gas block) and adding a pound to compensate for the weight difference of the receivers and the BCG, then adding the advertised weight of an Aero M5 handguard without subtracting the 12” CF handguard that’s on the 5.56 gun, I’m estimating 7.35lbs, or one pound lighter than a XM7 before accounting for the probably a bit heavier 6.5 barrel vs my 5.56 one. Might be able to get it between 8-8.5lbs naked without even using the lightest profile 13.5”-14” barrel.

*Mos Tek 13.5” Alpha profile. 0.7” diameter both before and after the gas block. Next size up is 0.750 before the block, 0.7” after. X-Caliber is similar with their 14” bbl. X-Caliber’s website shows that the shank is larger OD and longer with .308 profiles vs 5.56 ones. Mos Tek doesn’t say on their website.

[JediGuy]

I did the 308 deal a few years ago. Really the only gun I think I should not have gotten rid of.

Under 8 lbs isn’t hard with standard parts, at least with a 20” pencil barrel. Cut the handguard and barrel lengths back a bit, and you should be good.