Deer hunting .308 bullet, accuracy and load data for AR-10?

165 sst over 4895 is pretty happy in my 16" LR 308. cci 200 LR primers, FC brass. standard book OAL.

the new ELD-X bullets are intriguing, but i havent played with them yet.
 
This fall will be my first year to hunt with an AR10 . . . I normally use a 30.06. What kind of range do you get with your 308?
 
Pretty hard to mess this up, 'bout any 150 - 165 gr. .30 caliber bullet designed for hunting works just fine. I've used the .308 Winchester a bunch over the years and a lot of Hornady, Sierra and Nosler bullets went down range. Mostly fueled by IMR-4064, Varget and lately TAC powders.
 
Originally Posted By: btvThis fall will be my first year to hunt with an AR10 . . . I normally use a 30.06. What kind of range do you get with your 308?




I have never really shot it for distance. It is a very nice gun (Mine is the original DPMS Recon AR-10 from "pre-Sandy Hook"), but I neglect it as far as actually using it that much, just deer hunting in Minnesota and then South Dakota deer seasons yearly. I shot a coyote while deer hunting at about 300 some and a couple of deer past 200 with it w/ just federal power-shok 150gr that seemed to pattern alright, but like I said - I have neglected to use this gun much even though it is great to shoot.
 
I'll throw in my $0.02 here.

I've shot a .308 for years and years. Won the tri-county championship in a Detroit suburb in the Hunter class with a Rem 700 in a .308 Win shooting a Sierra 168 or 165gr bullet. Hunted w/ exactly the same load.

A 308 is more than capable of harvesting a deer out to 500yds. There's no velocity difference between a 16" or 20 barrel. 45gr of Varget or 42.5gr of H4895. I spent 7 days behind an Oehler 35P chrono with 4 different rifles, AR's w/ 16" & 20" barrels so I know.

You asked about recommended loads. Keep in mind you have a 1:10 twist. Having said that, the most accurate will be a 165, 168 oe 180gr bullets. My recommendation is to follow the info on the barnesbullets.com website. During those 7 days I found Barnes to be 100% accurate. Speed vs powder charge....... it is a fantastic resource. Load to an overall length of 2.800" which is SAMMI specs.

I can't speak to a 150gr bullet ESPECIALLY since your rifle is a 1:10 twist. 150's won't be as good.

Good luck and I hope this helps,
Kahuner
 
Originally Posted By: Kahuner There's no velocity difference between a 16" or 20 barrel. 45gr of Varget or 42.5gr of H4895. I spent 7 days behind an Oehler 35P chrono with 4 different rifles, AR's w/ 16" & 20" barrels so I know.



i have a hard time believing that similar charges in a 16" and a 20" barrel have the exact same velocity to them.

it goes against everything i've come to understanding regarding velocity and barrel length.

there may be some unusual circumstances where this MAY be true due to barrel finishes (ie: one barrel is a melonite, the other is stainless or chrome lined) and/or variance in bore rifling (polygonal vs lands and groove) causing less velocity in the longer barrel...

but as a general rule a 16" barrel should be slower than a 20" barrel, all else equal (same ammo, same barrel style/finish, same weapons platform) anyway.
 
The only way to conduct a meaningful comparison of barrel length to velocity would be to use the same barrel as done in this test. Trying to compare different rifles w/different length barrels introduces too many variables for any accurate data.

Quote:.308 Win Barrel Chop Test: How Velocity Changes with Length

With barrels, one wonders “Can a little more length provide a meaningful velocity gain?” To answer that question, Rifleshooter.com performed an interesting test, cutting a .308 Win barrel from 28"; all the way down to 16.5". The cuts were made in one-inch intervals with a rotary saw. At each cut length, velocity was measured with a Magnetospeed chronograph. To make the test even more interesting, four different types of .308 Win factory ammunition were chronographed at each barrel length.

READ RifleShooter.com .308 Win Barrel Cut-Down Test Article.


Test Barrel Lost 22.7 FPS Per Inch (.308 Win Chambering)
How much velocity do you think was lost, on average, for each 1″ reduction in barrel length? The answer may surprise you. With a barrel reduction from 28"; to the average speed loss of the four types of .308 ammo was 261 fps total. That works out to an average loss of 22.7 fps per inch. This chart shows velocity changes for all four ammo varieties:



Summary of Findings: The average velocity loss per inch, for all four ammo types combined, was 22.7 FPS. By ammo type, the average loss per inch was: 24.6 (Win 147 FMJ), 22.8 (IMI 150 FMJ), 20.9 (Fed GMM 168gr), and 22.5 (Win 180PP).

Interestingly, these numbers jive pretty well with estimates found in reloading manuals. The testers observed: “The Berger Reloading manual says for the 308 Winchester, ‘muzzle velocity will increase (or decrease) by approximately 20 fps per inch from a standard 24" barrel’.”

How the Test Was Done

The testers described their procedure as follows: “Ballistic data was gathered using a Magnetospeed barrel mounted ballistic chronograph. At each barrel length, the rifle was fired from a front rest with rear bags, with five rounds of each type of ammunition. Average velocity and standard deviation were logged for each round. Since we would be gathering data on 52 different barrel length and ammunition combinations and would not be crowning the barrel after each cut, we decided to eliminate gathering data on group sizes. Once data was gathered for each cartridge at a given barrel length, the rifle was cleared and the bolt was removed. The barrel was cut off using a cold saw. The test protocol was repeated for the next length. Temperature was 47° F.”


CLICK HERE to Read the Rifleshooter.com Test. This includes detailed charts with inch-by-inch velocity numbers, multiple line charts, and complete data sets for each type of ammo. Rifleshooter.com also offers ballistics graphs showing trajectories with different barrel lengths. All in all, this was a very thorough test by the folks at RifleShooter.com.


Much Different Results with 6mmBR and a Longer Barrel

The results from Rifleshooter.com’s .308 barrel cut-down test are quite different than the results we recorded some years ago with a barrel chambered for the 6mmBR cartridge. When we cut our 6mmBR barrel down from 33" to 28", we only lost about 8 FPS per inch. Obviously this is a different cartridge type, but also our 6mmBR barrel end length was 5" longer than Rifleshooter.com’s .308 Win start length. Velocity loss can be more extreme with shorter barrel lengths (and bigger cartridges). Powder burn rates can also make a difference.

http://bulletin.accurateshooter.com/2016...es-with-length/

Regards,
hm
 
I’ve actually been working on a deer hunting load for my 16” AR-10 over the summer and I’ve just about wrapped it up. I have a thread on here that I will update once I have all my info compiled. One things for sure is that there isn’t much data out there for specifically the AR platform, you really need to do your own testing with the individual firearm.

There are many factors of consideration, and it takes quite a bit of troubleshooting if you’re as anal about your load as I am. Now for me, my goal was I wanted the flattest shooter (within reason, accuracy 1st). Anything 30 caliber is going to kill, and when you do the math out for energy you can usually get a lighter bullet to equal the energy of a heavier bullet (within the range you’d shoot a deer at) however the lighter bullet will greatly extend your max point blank range, depending on how you decide to sight your scope in.

With the AR-10 platform you need to take into consideration the length of the barrel (powder burn), and how its going to function given its gas operated and semi-automatic. I had a member on here run a Quickload for me and it turned out H322 had a 99% burn rate in the 16” barrel, so I picked some up. The bullet I chose was the 125 grain Nosler Accubond, and the mindset behind that was if I’m using a lighter bullet I wanted it to be more stout and still be able to achieve a full pass thru on a quartering shot leaving a nice blood trail.

Before you even start fiddleing, I’d suggest an adjustable gas block which I found out was 100% necessary for my set-up. I first did ladder testing with the H322 looking for a powder accuracy node, which I found at 41.2 grains (2,750 FPS). I could have pushed it further velocity wise, up to 2,900, but with the AR-10 platform you have to balance your give and takes. I was happy with 2,750 FPS. You’ll also start seeing some primer flow, which I guess is normal, but it was good place for me to stop.

With this powder charge I then started bumping out my seating depth from 2.750” out to 2.800”, turns out 2.790” achieved the best accuracy. I may have achieved slightly more velocity but I haven’t rechecked the speed since I did the seating depth testing.

Anyhow, this was the results… 3 shots @ 100 yards. If I zero at 25 yards I’ll be 2.7” high @ 100 yards and zeroed at 225 yards, which covers any shot I’ll see in the northeast.

 
I'm wanting an AR10 too. Want to build it myself. That's a pretty nice group also. Why did you go with a 16" barrel instead of a 18"or 20" ?? Thanks
 
Originally Posted By: yotekiller47I'm wanting an AR10 too. Want to build it myself. That's a pretty nice group also. Why did you go with a 16" barrel instead of a 18"or 20" ?? Thanks

just a fair warning, the AR-308 market isnt all "mil spec" like the ar15 market is, so make sure you do your research. there are at least 3 different proprietary platforms, but some crossover for some parts, but not all. so do your homework before you click the "ship it now" button.

generally speaking you have the DPMS platform, the AR-10 Armalite platform, and a couple of the smaller company's have semi proprietary builds out there as well. If memory serves me correctly PSA and franklin come to mind, but please dont hold me to that if i got the names wrong.


again, just make sure that all your goodies are compatible with whichever baseline build you decide on.

HTH
 
Originally Posted By: yotekiller47I'm wanting an AR10 too. Want to build it myself. That's a pretty nice group also. Why did you go with a 16" barrel instead of a 18"or 20" ?? Thanks

I purpose built the setup for deer hunting, so lightweight and compact were two main considerations. Unless your shooting long range and need that extra bump in velocity their isn't much need for a longer barrel in 308. The barrel I chose is a lightweight profile and the gun weighed out to 8.3 lbs. with no scope, which isn't some record or anything but it's decent for a 308 on a tight budget.
 
Lightweight and compact aren't words used in conjunction with the AR10 platform. They just are what they are.
 
Originally Posted By: GCLightweight and compact aren't words used in conjunction with the AR10 platform. They just are what they are.

You're right about that but you can try and mitigate it as much as possible if you're dead set on the platform, for sure none are "light" they're all chunkers. My AR-10 is smaller and lighter overall than my AR-15 that I built as a bench shooter. Not lighter than a bolt gun but you have to compare semi-auto's to semi-auto's.
 
Every one I have held was heavy feeling. I guess this is because it is a beefier platform than 5.56 I have 5 .308 bolt guns and love them. Just really have the itch for a semi auto. Like Plant One said, there are different platforms. I don't understand why they can't make them like the 5.56. It's hard to get away from bolt guns, but, it's kinda like the women, play the field and see which one you like best. Only thing is the weapons don't talk back and for the most part do what you want.
 
I don't mind heavy guns, even though I don't really consider my AR-10 heavy at all. I can keep it really steady for long running shots, which is what I mostly get out in South Dakota. Here in Minnesota the shots are usually standing still under 100 yards. Either way, I've never complained about how much a gun weighs and I've packed miles with 10+ lb guns chasing coyotes in Western South Dakota and never thought that a gun 3-5lb lighter would make all that much of a difference. If the gun is too heavy for you, hunting on foot isn't your thing to begin with.
 
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