Since the OAL is limited because of the mag, is it worth loading 7-08 in an AR, or should I just stay with 308? Purpose is long range steel killing. What bullet would I have to go with. I do handload.

Thanks!

IMO, no, I'd go 308, since it's a gas gun. I can kill steel just fine with my 308 gas gun. But, you could run the 7mm 160 or 168 grain SMK or maybe the Hornady 162 grain BTHP. It might fit in the mag with a slight jump. You'd have to run the COAL numbers to see if it would fit. Find out the tip to ogive length on each bullet, and then add it to the case length, and that will tell you if it will fit or not at the 2.800".

7mm-08 case length = 2.035"

7mm Ogive to tip lengths

168 SMK = .665
175 SMK= .724
162 A-max= .750
162 BTHP (Hornady) would be less than the 162 A0max for sure.

With these numbers and seating the bullet at the ogive, here's your COAL.

168 SMK= 2.700"
175 SMK= 2.759"
162 A-max= 2.785"
The 162 Hornady BTHP would be less than the A-max, so you'd be around 2.740 or so, I'd guess.

The 7mm 168 SMK would give you the most room for seating the bullet out further. If you went that route, then that would be a good 7mm in a gas gun.

The info is much appreciated, Chad. So overall, you'd still choose 308?

Honestly, a 308 is hard to beat. If you wanted a little more BC than the 708 would be good.

G1 BC of a 175 SMK = .475

G1 BC of:

7mm 168 SMK= .565
7mm 162 Hornady bthp= .610

Those BC numbers would give you some advantage in the wind out past 500 yards, especially the 162 bthp. A 162 bthp in the 708 pushed about 2650 to maybe 2700 would be nice.

7mm08 & 243 & 308 all use the same mags. I have an DPMS AR 10 & @ Remington R 25's, one in 7mm08 & one in 243. All 3 use the same mags. The DPMS mags work just fine in the Remington's & vice versa. Magpul also work in both.

The 140 vld is maybe a option depending on chamber. There are also rumors of a 140 hybrid which would work very well.

The 168gr Sierra is one I've played with a good bit and really like the ease of loading and accuracy.

The sierra 7mm 168 has a .488 g1 bc......may as well just shoot a 308.

These are two quotes from my post when I finished my 7mm-08 AR10



Followed by


My barrel is having to be throat reamed to to fix a small imperfection from the chamber reamer, but I should have a full range report on 162 Amax loaded to mag length within a month, and also with in that month I hopefully will be able to go take my class with Fireman and he can tell you how he likes it too.

Litz put the 168gr mk at .565 on g1 bc and that has been spot on for my drop and drift data out to 1000.

Thats a hell of a difference. I just looked it up. .565 is what Litz tested it at.........That's a little strange, usually sierra is almost spot on. Good to know.

I know I had some reservations when I first gave it a try but it's worked well.

I actually use 300 win mag magazines for my long action savage 7mm08 chassis gun. No problems at all.

Sweet. Just ordered a lower and will order the barrel soon. Best barrel length? I'm think either 20" or 22"

Thanks y'all

My ai wears a 22" barrel and I'm very happy with it.

Just remember that you will loose a bit of velocity compared to a bolt gun.

Correct. You will lose about 75-100 fps over a bolt gun. The added barrel length will help increase speed by about 20 fps per inch.