Oh, I am going with FAL mags, but for my FAL. My point is that if magazine selection were the most important criteria, you’ll be picking a LAR308 because FAL mags work, are battle proven, very rugged, last a long time and can be found fairly cheap. While a good magazine is a must for any rifle, there is much more to choosing an AR 308.
Just because a lower is compatible with a P-Mag doesn’t automatically make it a good choice. There has to be a better reason. The DPMS LR308 upper is made from “Thick walled, extruded from 7129-T5 Aluminum”. While extrusions make for good parts, I’m not sure it’s better than forging. Is 7129 picked because it’s more durable than 7075 or, which is more likely, because the alloy has better properties for extruding than 7075? (I haven’t researched this yet). Why is it thick walled? Does it need beefing up to be stronger? Thicker walls means more weight.
The DPMS lower is “Milled from a solid billet of 6061-T6 aluminum”. No thank you on both counts. 6061 is less durable than 7075 and billet lowers aren’t as strong as forged. While the DPMS LR308 accepts P-Mags, it has features that are less than desirable.
Let’s take a look at the LMT- It’s P-Mag compatible. It’s HOLY COW- over $2800! That’s a pile of money to be spending just to get a rifle using cheaper magazines than an AR10! They didn’t list what the receivers were made from, but at that price, they’d better be good. We already know what kind of sticker shock (and yes, quality too) we’ll get looking at KAC.
The LaRue PredatAR is $2500. Still a chunk of change to avoid buying the more expensive AR10 mags. However, the Larue does come with a free float forearm and the AR10A4 has the standard handguards. LaRue shows the PredatAR receivers being made from 7075, but they are billet. Another plus for the PredatAR is it’s lightweight.
I haven’t found what alloy RR is using for their LAR308 receivers or if they are forged or billet. Also, I don’t know if FAL mags work well with the AR type bolt.
The AR10, while it isn’t P-Mag compatible has much to offer. Receivers are forged from 7175, an alloy tougher than 7075 and both are tougher than 6061. The second gen AR10 magazines are an improvement over the original versions although reports of their reliability have been anecdotal and remain unproved. The AR10A4 isn’t as light as the PredatAR, but it’s lighter than other AR 308s. Also, the upper & lowers are available stripped for a reasonable cost and assembled to the shooter’s liking.
308 P-Mags, by all accounts, are good magazines, but an AR 308 lower has to have more going for it than being “P-Mag Compatible”. KAC & LMT are expensive. DPMS isn’t up to spec. While other options remain to be explored, the AR10 and it’s magazine isn’t looking so bad, after all