7.62x39 vs .308

[91RR]

I am considering building either an AR 15 in 7.62x39 or an AR 10 in .308. Anybody have any suggestions?

[Hoser]

What do you plan on using it for?

7.62x39 is fine, but runs out of gas past 400-500 yards compared to a 308. No decent match ammo is avail for it also.

[91RR]

I am looking to build an AR that I can use for hunting here in CO. Mainly for deer and I don't think I have ever taken a shot past 300 yards in the past 5 years most have been about 100.

[Colorado Osprey]

The issue with 7.62x39 AR's has always been magazine reliability and availability. C-products has figured it out... Finally!
I see no reason to ever get a heavy and large AR-10.
There are better semi-auto 308 rifles out there for less money.
The down fall to the 7.62x39 is the lack of velocity compared to the 308.

If that still doesn't sway you, read on.........

Mike Milli of www.dtechsuperstore.com is the pioneer of the WSSM in the Ar-15 platform. He is also instrumental in alternate caliber chamberings for the AR-15 form .17 to .358 chamberings. Not sub-sonics like the SOCOM or the Whispers.

Mike is making/selling a 300/25WSSM wildcat that will perform equal to or greater than the 30-06 fitting into a standard AR-15 lower; with 160-180 grain bullets!! That puts the 308 in the heavy and large AR-10 to shame.

Remington also developed a new 30 cal AR cartridge; Remington's new 30RAR which is their version of a 450 Bushmaster necked down to a 30 cal. That round isn't even getting to 308 velocity with 125 grain bullets. Look closely at the data and they compare the 308 with a 165 grain bullet to the 30RAR and a 125 grain bullet!
http://accurateshooter.wordpress.com/2008/10/15/remington-introduces-new-30-remington-ar-cartridge/

What say the rest of you??

[Colorado Osprey]

No one else with an opinion?

[91RR]

I think I might have found what I want. I think I might have to get one of Mike's uppers chambered in .243 WSSM.

I would still like to hear any other opinions out there.

[Hoser]

Easiest conversion is the 223 necked up to 6mm. Its hell on coyotes and should be fine for deer inside 300 yards.

[Colorado Osprey]

Easiest conversion is the 223 necked up to 6mm. Its hell on coyotes and should be fine for deer inside 300 yards.

I have one of those form Mike Milli in a 20 Bull barrel it's called a 6x45... about 30% more power/energy on target over the 223. A bit light for elk though.

[jh308]

I'd go 6.8spc or 6.5grendel if I was inside 300yrd. 6.8spc if I didn't reload. Mine is about 1/2the weight of my 7.62(LR-308) A 85gr TSX traveling 3000fps out of a 10" bbl will have no problems w/deer. Probably a bit light for elk tho.

[AP-4Guy]

I'm not trying to be disrespectful, but I'd be very skeptical of your friends' numbers. Physics being what it is, I just don't believe you can get "30-06" performance out of a round that will fit into a 5.56 magwell. l just don't believe it is possible. I also disagree with your premise that .308 AR's are heavy. They can be, yes, but check into the 16" AP-4 from DPMS. I may sound and look biased, but Google "DPMS AP-4 reviews" and you'll see what I mean.

[DOC]

They are both fine rounds. But the .308 tends to be more expensive.

[Colorado Osprey]

I'm not trying to be disrespectful, but I'd be very skeptical of your friends' numbers. Physics being what it is, I just don't believe you can get "30-06" performance out of a round that will fit into a 5.56 magwell. l just don't believe it is possible.

No disrespect taken, he's Not My Friend, just a custom gun builder that has outstanding product, knowledge and a great following and reputation. In hunting AR-15's Mike Milli and Dan Carey are kings of the AR-15 custom builds. Dan Carey just doesn't have propietary access to the WSSM platform parts. Mike Milli doesn't claim those 30-06 spec numbers... his clients... acutual users do. He finds them difficult to believe too.

Think of almost the same case capacity as a 308, but a more efficient bottle neck case design like the PPC and BR cartridges. That's what makes it more efficient than the 308 case.


I also disagree with your premise that .308 AR's are heavy. They can be, yes, but check into the 16" AP-4 from DPMS. I may sound and look biased, but Google "DPMS AP-4 reviews" and you'll see what I mean.

LR-308 AP-4 16" CAR stock ***** 8.5#'s and that is a light one!

So to compare to a long barrel light AR-15:
300/25WSSM stainless fluted 22" rifle weights only 6.5#'s

Mike's fluting is not cosmetic. (between 1/3-1/4 of total barrel weight gets removed)

You might google Mike Milli or "Dtech" as he goes by in forums; or give him a call, he'll give you tons of refrences all over the country.(he's a great guy to pump for information.) Mike also builds bustom AR-10's. I'm sure he can get that weight of the AP-4 without cutting the barrel down so much.

Oh, yeah. One last thing. By neutering the 308 down to a 16" barrel in a gas system rifle the velocity loss is staggering(more than 400ft/sec) compared to a 24" bolt rifle. The velocity is above the 7.62x39, but almost exactly the same as the 1890's military round the 30-40 Krag.

Don't get me wrong... it sounds like you want a 308 AR... go for it. Don't let me slow you down at all. It is just not for me. I like the versatility and wide range of stuff available on the smaller brother.

[91RR]

Well I have my upper coming and it was not at all one of the two I was originally looking at. I really liked the look and reviews of Mike's product but unfortunely after over a week of trying to contact him I have been unsucessfull. I found someone selling a 450 bushmaster at a very good price so I jumped on it. From what I have read it should be accurate enough for the distance I'm looking for and will definately have enough knock down power for anything that gets in its way. Ammo might be a bit pricey but I sure it is no more than what I'm paying for my 338 win mags. I will post my thoughts after I get it and take it shooting.