Capability of 308 out of 16" AR10?

D

Dashunde

New member
I'm on the fence picking optics for my new RR Predator 16".
(I have another similar thread that has guided me to this point, so far)

I'd like to know if a quality 16" 308 is *worthy* of a 4-12x40 (Nikon P-308 $300) or 4-16x42 (Nikon M-308 $400)??

I'll definitely go with a 1-6x24 for 100-400 yards, and I've not yet completely ruled out a EOTech holo for ~100 yards.
(Very much seeking lightweight options for a holo sight)

I'm really wondering if a shorty 308 can make good use of 12+ magnification optic?
 
Last edited:
I don't know how much difference 2 more inches of barrel makes, but my 18" Ruger Predator is about 50-60 fps slower than my 22" rifles.

I can do anything I need to do with a 308 with 6X to 9X on the upper end. I don't see the need for 12X unless you are shooting very small varmints at long range with an extremely accurate rifle. I'd think a 1-6X scope would do fine well past 400 yards, and a 16" barrel will get you well past 400 yards.
 
"I'd like to know if a quality 16" 308 is *worthy* of a 4-12x40 "

IMHO---NO
Unless you plan to do most of your shooting beyond 400 yards, I see zero need for a 12X scope on ANYTHING but especially something like a 16" .308.
It doesn't take a long barrel to be accurate but it does take bore length to generate velocity required to send ballistically efficient bullets long distances.
 
I'm really wondering if a shorty 308 can make good use of 12+ magnification optic?
Click to expand...
That is a personal decision that only you can make....but I will try to help you decide.:)

It is still a rifle, and you are not loosing that much velocity. For me it is not the cartridge that determines the power of the optics. The target size and distance are of more importance. Small targets at long range need more power. I have a 22 LR with a 6-16 power scope. For what I do with it I would have as much fun using iron sights....but I have another 22 for that. This set up is great for plinking empty shotgun shell casings at 25 yards, hunting grouse, and punching holes in paper while my hunting rifles cool down The scope makes it easy for my kids to use the rifle too. (They are young and still learning)

You didn't say what your intended use is. But I assume since you listed multiple sight types that you haven't decided, or you plan to switch sights for the task at hand.. Are you planning to use this rifle for a specific purpose?
 
I'm in agreement with big al , OP needs to first realistically determine max shooting distances and size of targets. A standard NRA target uses a 6 MOA black area relative to distance. (a 100 yd target is 6" dia black, and a 300 yd target is 18" dia black) so for 100-200 yds a 6x or 8x optic is all that's really needed. However trying to ring a 6" gong at 300 yds you will be better served with 12-16X. Remember if unsure of distances and target size , you can always dial down magnification on a higher power scope, you can't dial "up" a fixed power scope. If I had a 16" AR10 I would probably run a nice 4-12X as a good "all around" <300 yd combo. A 16" .30 cal rifle can reach 500 yds with good consistency, not sure I would be confident with a 16" bbl beyond 500 yds. I shoot a lot of different rifle/ scope combos out to 600 yds regularly, and i've shot 1K a few times. These are strictly just my opinions.
 
Thanks all.. use is light weight, *all purpose* 308 (if such a thing exists).

I'm really just wondering if a 4-16x40 or 42mm is worth messing with on a 16" 308?
If not I'll continue to focus on optics up to 600 yard max.
 
If you are going for small targets at extended distances, yes, a good scope is valuable. (I'd even say most people would suggest a step up from the scopes you listed, if you plan to do a lot of work past 500yds.)

Usually, .308 is considered about an 800yd cartridge, for precision shooting. Most loadings will drop subsonic in that neighborhood, which with many bullets means a reduction in accuracy. Using a longer barrel (to a point), will give you more velocity, which will keep the bullet supersonic to a longer distance. That is why you see a lot of 6 or 6.5mm chambered guns for long-range shooting these days.
 
A couple of points to consider, people like to look closely at the target, and a high power variable allows this. However, it is almost a given that if you ever need to use the rifle in a hurry, the scope will be set on it's highest power.

Unless you train yourself rigorously to ALWAYS turn the scope down to low power after shooting is done.

The other point is that when you get above 9x EVERYTHING gets magnified more. From heat shimmer to the jarring effect of your heartbeat on the crosshairs.

I use a 6-18x and a 6-24x on varmint rifles, and while its nice to crank it up to get a good look, I turn it down to 9x or lower to actually shoot.

3-9x works well for a wide range of uses, and for rifles used in deep woods situations 2-7x is better and a 1.5-4x is about ideal.

Everyone is different, but I've always felt that if you can't see it to hit it at 9x or lower, you shouldn't be shooting it.
 
I can confirm TX_Nimrod's article on the carbine-length AR-1-(like) ballistics, including the (~300yd) 8" gong point-blank range.

2mhfywo.jpg


Since I regard 4X as a "standard" benchmark for 100yds -- especially in a sub-minute capable rifle -- I'd suggest the 4-12X to be a good choice.
 
I'm old, bad eyes. My motto--no such thing as too much magnification (except at close range). If you are expecting sub-MOA at 600--then I'd be thinking about more than even 3 x 9. I have a 4 x 12 on my AR 10 carbine and I never feel it's too much at 100 yds. Might be an issue if CQB is part of your plan--but a "do-it-all" gun is generally going to be a jumble of sub-optimal compromises in my experience. :) I generally go for "simplest approach to doing one thing well" because that's about all I'm capable of.
 
I, my wife and a few friends I have loaned the rifle to have killed elk (several of them) with my Mossberg 18" MVP. No problem at all.

I have owned quite a few 308s in my life, and I still own 2. A Ruger SR762 (16.5") and the above Mossberg.

I have chronographed the ones I have owned as well as both of those I still own with various ammo. I have found that 20 to 25 FPS per second is the average difference from a 16" up to a 22 inch barrel, and past 22 " you gain about 18-22 fps at 25" and 26" I never had a 308 with a barrel longer then 26"

None of that made any difference on deer antelope or elk.
 
I had a 788 Rem that had a buldge in the barrel from previous owner shooting it with a obstruction. I had it cut off and ended up with 171/4" barrel. I had a 6x on it and it shot under 1" at 100yds with Rem factory 150gr.
 
I have 1st and 2nd round hits on targets at 1k yards with an M1A CQB. It had a 16" barrel. About a dozen witnesses at Camp Butner to prove it. So the answer is... yes, that snubby is capable of stretching legs of a 12x scope. It wasn't my rifle, and I didn't think it was feasible (possible but not likely). So, the instructor pulled his rifle out and handed it to me, telling me to have at it. Lo and behold, the thing would do it.

That being said, it is not the best tool for the job and if you don't foresee yourself shooting further than 400 yards with it a 6x scope will suit you well.
 
Thanks for all the info and perspective everyone.

Seems the 1-8x24 Vortex might be just about right and a better balance of most all factors?
It bumps up the magnification from 6x to 8x for a bit more versatility and it comes with a decent mount.
 
My 16" .308, which I mostly use for 3Gun, wears a Burris XTRII 1-8. For me, it is about perfect for a .308 gas gun. I shot a few 1000 yard matches, a few deer and a few pigs with it, but mostly I am shooting targets from about 70 to 600 yards.

Please don't buy a Strike Eagle. It won't last and it has a lot of parallax, almost useless past 200 unless you like to spray and pray.
 
"So, the instructor pulled his rifle out and handed it to me, telling me to have at it. Lo and behold, the thing would do it."

And so will numerous other platforms once zeroed for the range. This discounts the fact that 40-50 yards closer or farther would result in a miss.
 
You must log in or register to reply here.
Back
Top