Which .308 Bullets for 1,000 yds in a 20 inch AR-10 will work best???????????

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XXXXX

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Minuteman
Jan 27, 2013
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#1
Lapua 155 gr Scenar with G1 BC of .508. But how far will it hold that BC and what does it drop to when it drops? Also, that bullet has a large hollow point cavity, so with such little weight in the nose, I would guess it can get rather twitchy ( sensitive) in the wind at 800-1000 yds compared to a 175 gr SMK at 800-1,000 yds.

The Sierra Match King 175, BC .496 (or is it .494), but holds it well at 308 Win velocities.

Hornady's 178 gr BTHP with BC .530. Don't know what the BC is at 800 to 1000 yds though.

Hornady AMAX 175 (178?) but has slightly lower G1 BC than the Hornady 178 gr BTHP

Nosler's Custom Competition 190 gr, BC .530. This bullet has a sharper taper nose to keep it's oal down. With that plus the 190 gr weight, there's a lot of nose weight which in theory will give the bullet more stability as it slows down below 1250 fps. The most accurate bullets in 1000 yd BPCR have a fair amount of nose weight for the same reason, eg: Theodore's 45 cal elliptical bullet for those of you that dabble in BPCR.

From surfing the net the last week or so, I am not aware of any 168 grainers that reach 1K with reliable accuracy, so that's why I didn't list any here.

I know the Palma guys like the 155gr Scenar bullet a lot, and they are limited to a weight of 155 gr.

So for you guys who shoot a lot of 1,000 yds with 20 inch AR-10's, what bullets from above (or others) work best at 1,000 yds? And what kind of propellants are you using to get a consistent velocity?

Can you get match grade accuracy out of Lake City standard pulled brass (standard brass that has been primed with a C34 primer and the bullet has been pulled) , even if you have to work it / turn it and check it to get it???

Thanks!!

Thanks. As you can tell now, I am interested in shooting 1,000 yds with a 20 inch barreled AR-10 and to use the LC brass
 
#3
24" barrel here. AR-10T.

My load is 175gr SMK, 44.6gr Varget, Lapua brass, plain CCI LR primer. I think I have the bullet seated pretty far out. I've read that the OAL of the AR-10 mag might be longer than certain DPMS pattern mags.

I get 2690ft/s and it does pretty darn good out to 950yds. I get no pressure signs and it runs really clean, no soot on the neck. I try to keep the chamber clean since just barely bump the shoulder.

RL-15 is pretty temp sensitive in my 6.5x47L. Not sure if that translates to a 308 cartridge with a large rifle primer.
 
#4
Well unfortunately right now I think it will depend on what you can find. If you already have all three then you are set. I am still in load development for my 20 incher but I am planning on 175 SMKs since that is all I have a supply of. What is your barrel twist? A ballistics computer will tell you what your MV needs to be in order to get each of those bullets out to 1000 yards supersonic. At 2,550 FPS a 175 SMK (G7) is stable out to 1110 Yards so you should be set with either you choose.
 
#5
AMU's 1,000 yard teams have been using the Berger 185 Hybrid, and posting good scores with them. The 155s aren't likely to work well for you, as they need a longer barrel to get the speeds that will keep them supersonic at the target. Yes, we do use them in Palma, as the rules require, but our guns are set up for this, and most run 29-30" barrels to get all you can out of the 308 cartridge. You'll need somewhere right around 2950 fps with that bullet to make sure it's good all the way out, and that's asking too much from a 20" AR. We (my team mates and I) recently built several AR-10s on the AMU M110 pattern, and intend to use them at Perry this year. Ours are all set up with Satern cut rifled barrels, 1x9.3" twists, to use the Berger 185 grain Hybrids. We're using the AMU load for this combination, as there just didn't seem to be any point in reinventing the wheel.

The various 175s out there will all need right around 2,600 fps to keep them supersonic on target. Might be possible with the 20", but you'll be pushing them pretty hard.
 
#6
I have had good luck with the 175 SMK, 178 A-Max and the 185 Berger BTLR. All out of a 18" Mega Maten. I have about 400 Lapua Cases I load the Bergers in over 43g of either Varget, RE15 or Ramshot TAC. I also load a M118 LR clone with 175g SMK in fully prepped LC brass, CCI BR-2 primer and 44.4g of XBR8208 which has been fantastic. It's just about as accurate as the others in Lapua brass. I loaded 1K of these with the XBR after working up a load because I found an 8lb jug of it for normal price. As stated above it's about what you can find right now, not what you want.
 
#7
XXXXX said:
Lapua 155 gr Scenar with G1 BC of .508. But how far will it hold that BC and what does it drop to when it drops? Also, that bullet has a large hollow point cavity, so with such little weight in the nose, I would guess it can get rather twitchy ( sensitive) in the wind at 800-1000 yds compared to a 175 gr SMK at 800-1,000 yds.

The Sierra Match King 175, BC .496 (or is it .494), but holds it well at 308 Win velocities.

Hornady's 178 gr BTHP with BC .530. Don't know what the BC is at 800 to 1000 yds though.

Hornady AMAX 175 (178?) but has slightly lower G1 BC than the Hornady 178 gr BTHP

Nosler's Custom Competition 190 gr, BC .530. This bullet has a sharper taper nose to keep it's oal down. With that plus the 190 gr weight, there's a lot of nose weight which in theory will give the bullet more stability as it slows down below 1250 fps. The most accurate bullets in 1000 yd BPCR have a fair amount of nose weight for the same reason, eg: Theodore's 45 cal elliptical bullet for those of you that dabble in BPCR.

From surfing the net the last week or so, I am not aware of any 168 grainers that reach 1K with reliable accuracy, so that's why I didn't list any here.

I know the Palma guys like the 155gr Scenar bullet a lot, and they are limited to a weight of 155 gr.

So for you guys who shoot a lot of 1,000 yds with 20 inch AR-10's, what bullets from above (or others) work best at 1,000 yds? And what kind of propellants are you using to get a consistent velocity?

Can you get match grade accuracy out of Lake City standard pulled brass (standard brass that has been primed with a C34 primer and the bullet has been pulled) , even if you have to work it / turn it and check it to get it???

Thanks!!

Thanks. As you can tell now, I am interested in shooting 1,000 yds with a 20 inch barreled AR-10 and to use the LC brass
Click to expand...

I run a Sig 716 with a 16 inch barrel and the rifle seems to like Hornady TAP 168 Amax best. I shoot 1000m steel and unfortunately at 900 meters (984 yards for you) the bullets go subsonic but if im stepping starting at 700 meters I get there no problem because im adjusting accordingly, if I try to shoot 1000 cold it sometimes takes a couple to get on target because the calculations sometimes bring it up a bit short. Density altitude is also in the 5,000s around here though with the heat, so you may get over 1,000 before it goes subsonic. I tried heavier Federal GMM and a few rounds blew out the primers in my gun so I stuck with the 168s, but when I did use the 175s they would pound the steel and stay supersonic past 1000. My buddy has made up some custom loads in his gun that run better than mine but I don't reload currently and just stick to factory ammo.
Of all the rounds I found the GMM 168 grouped the best at .5 MOA, followed by Hornady at .7-.8 MOA, and I really didn't get that great of groups with the 175s at just under an inch, but I also only tried 10 rounds before I went back to the Amax. The 175s are definitely superior in the short barrel to 1,000, but I have the least issues and most consistency with the Hornady so that's all the gun shoots now.

I have some Hornady Super Performance Match 178 but that only goes in my bolt gun as ive heard it doesn't run well in semi autos and out of the bolt gun last week I got a .31 inch group. I have yet to really test them hard though and that was my first time out with the rifle just to sight in the new ATACR. For consistency on the bolt gun, the 175 SMKs are incredible and even in my Savage FCP 5R I could hit the 1000m over and over until I ran out of ammo.

Im really hoping to find a decent deal on an 18 or 20 inch AR soon to play with but Sig is slacking on release of their DMR, and I don't want to spend 4K on a custom gun when I seem to do just fine with the off the shelf name brands.
 
#8
I just spent the past 3 days watching a lot of .308 go downrange from 20" barrels. Out of all the .308's there, my buddy's 30" F-Class bolt gun running 185 Bergers pretty fast would be what I would want if forced to use a .308, with Palma brass.

If you really want to get the most out of the AR10 20", and can afford it, get Lapua Palma brass and run the Bergers. The balancing act your gas system/recoil system will need might limit you away from lighter pills, but sounds like a fun endeavor that will eventually lead to getting a 6.5 variant if you're really shooting a lot at 1000yds.

I got out of .308 years ago because I really do need to shoot out to 1000m+, and I found it to be barely a 600yd 1st-round hit probability cartridge at best for me. Ballistics software and some of the newer bullets have extended that effective range somewhat, but you're a world-class shooter if you can predictably make a 1st-round hit on an IPSC steel with any .308 even at 900yds. The rest of us are lucky to get a 2nd-round connect. Most times it involves bracketing the target with a good spotter and steady wind conditions.
 
#9
LRRPF52 said:
The balancing act your gas system/recoil system will need might limit you away from lighter pills, but sounds like a fun endeavor that will eventually lead to getting a 6.5 variant if you're really shooting a lot at 1000yds.


If the gun's a gas piston gun, that would be more efficient than gas impingement in preserving velocity, right? Less gas is used to move that piston up to actuate the rod than gas used to move through a gas block followed by going down the gas tube on a typical setup, correct?
Click to expand...
 
#10
After try out a lot of combinations using a variety of bullets and powder, I found a pretty good recipe for getting hits on steel at 1000 yards using a 16" 308 AR. Heavier bullets seem to be the way to go out of shorter barrels from my experience. My current load is a Nosler or Sierra 190 grain BTHP over 43 grains of Hodgedon CFE-223 in FC brass. Muzzle velocity isn't very high at around 2520 FPS, but the 190's hold velocity really well. Velocity at 1000 yards out is slightly over 1200 FPS according to "Shooter" android app.

I'm getting hits about 60-70% of the time on an 11X18" steel plate at 1000 yards using this load out of a Rainier Arms "Select" 16" barrel. With a higher quality tube, I'm sure the hit percentage would go up considerably. The same load out of my 24" Savage 10FP is extremely consistent at 1000 yards, almost to the point of being boring. I would imagine this load would also perform very well out of a 20" barrel.
 
#13
XXXXX said:
LRRPF52 said:
The balancing act your gas system/recoil system will need might limit you away from lighter pills, but sounds like a fun endeavor that will eventually lead to getting a 6.5 variant if you're really shooting a lot at 1000yds.


If the gun's a gas piston gun, that would be more efficient than gas impingement in preserving velocity, right? Less gas is used to move that piston up to actuate the rod than gas used to move through a gas block followed by going down the gas tube on a typical setup, correct?
Click to expand...

The way I see it, the op-rod driven guns need larger gas ports to move even more mass, because you have to move the op-rod and the carrier, which hasn't been reduced in weight with the op-rod systems. The excess gas is bled off of both systems-one does it at the gas block or tube, and the other does it at the bolt carrier.

From everything I can see, the DI system is more efficient and has proven to hold better accuracy potential, while being an extremely reliable design compared to other assault or battle rifles and their operating systems. When I look over how many high-volume courses I have been run through, attended, or run myself, the DI guns have been the dominant, consistent performers.

For long-range work, I have yet to see an op-rod driven system that compares to the DI guns as far as accuracy is concerned.

As to the 168gr .308 pills, the SMK was really meant for the 600yd line, and most 168gr pills from competitors have followed the same profile and BC range as the SMK's .447-.462 G1 drag co-efficient. The Lapua 167gr Scenar has a .446 G1, and the Hornady 168gr BTHP has a .450 G1. The Hornady 168gr A-MAX, however, does have a G1 BC of .475, which puts it ahead of the SMK's and Lapua's, but the 175gr .308's have increasingly become more and more popular for those stretching the legs of the .308 Win.

When shooting out to 1000yds, most shooters have realized that bullets with a .500 G1 BC or higher really help cut through the wind better, and retain their energy sufficiently to stay supersonic and away from transonic flight enough so that gyroscopic stability is still there. This is why I feel strongly about the statement that the 7mm should have been what the 7.62x51 NATO became if we were going to be stuck with the T65 case by Army Ordnance Board stubbornness.
Click to expand...
 
#14
Another option to consider; the first shipment of the new Scenar Ls is arriving at Graf's within the next few weeks, including the new .308" 175s and 220s. I got a chance to check out the 175s at the IWA show in Nuremburg a couple months ago, and it looks like it should be the new "standard" for this weight range. Haven't done the Doppler firing with these yet (sometime in late June or early July, from what I've heard) but the BC should be significantly higher than the SMK. Better profile ogive, long BT configuration and tighter QC standards all the way around. Should be a winner.
 
#15
ksthomas said:
Another option to consider; the first shipment of the new Scenar Ls is arriving at Graf's within the next few weeks, including the new .308" 175s and 220s. I got a chance to check out the 175s at the IWA show in Nuremburg a couple months ago, and it looks like it should be the new "standard" for this weight range. Haven't done the Doppler firing with these yet (sometime in late June or early July, from what I've heard) but the BC should be significantly higher than the SMK. Better profile ogive, long BT configuration and tighter QC standards all the way around. Should be a winner.
Click to expand...

man that sounds great! I never liked the 155gr in any of my guns (1/10, 1/11.25, or 1/12 twist). The 175 gr SMK's are easy to load, just get them between 2500 and 2550 fps (for 20" barrel) or between 2650 and 2700 for a 24" barrel, and the groups will be tight in any gun. The 155 has awesome numbers on the books, but when I go shoot them, the groups are never consistent. To be fair though, the places I shoot at has a lot of wind, and it just seems the 175gr SMK does better with the wind. I am sure if there is no wind, the 155gr Scenars could probably shoot the nuts, it is just I have never experienced it.
 
#18
The Transonic range depends upon your load, rifle, DA and bullet design.

Put your load data into a ballistic computer like JBM, max distance of about 1300 yds, and use 25 yard increments and it will show you around the distance you'll enter the transonic range (somewhere below 1100 FPS). Remember Temp and or DA will affect these numbers so hopefully you've captured your load data and environmental numbers accurately. The Sierra and Hornady generally tend to transition well, but again it depends upon how far you're pushing past that zone and some other factors.

The Palma case uses a small rifle primer vs. a large rifle primer in the standard .308 Win case.
 
#20
ksthomas said:
amu's 1,000 yard teams have been using the berger 185 hybrid, and posting good scores with them. The 155s aren't likely to work well for you, as they need a longer barrel to get the speeds that will keep them supersonic at the target. Yes, we do use them in palma, as the rules require, but our guns are set up for this, and most run 29-30" barrels to get all you can out of the 308 cartridge. You'll need somewhere right around 2950 fps with that bullet to make sure it's good all the way out, and that's asking too much from a 20" ar. We (my team mates and i) recently built several ar-10s on the amu m110 pattern, and intend to use them at perry this year. Ours are all set up with satern cut rifled barrels, 1x9.3" twists, to use the berger 185 grain hybrids. We're using the amu load for this combination, as there just didn't seem to be any point in reinventing the wheel.

The various 175s out there will all need right around 2,600 fps to keep them supersonic on target. Might be possible with the 20", but you'll be pushing them pretty hard.
Click to expand...

this is good knowledgeable advice...... Use it.................
 
#21
Lots of great info in this post... all roads I have been down myself as well. I settled on the Hornady 178BTHP in my 20" MA-Ten. Tried running 168SMK, 168Hornady, 175SMK, 178 Hornady and 155 VLD. The 155 gives you more velocity and has a great BC for the given weight, but once you start pushing it out, wind and stability are more greatly effected due to the lower mass. The 178 and 175 are both good compromise bullets in the 308. You can get their velocity up with the right powder, but still have the decent BC.

Of the heavier 308's, I stick with the Hornady. It has a slightly better BC than the SMK, and is less expensive to shoot (and let's face it, right now who couldn't stand to save some cash). I also tested several powders in LC brass including RL15, 4895, 4064 and Varget. I seemed to get a little better accuracy node with the RL15 and continue to use that in my 26" bolt gun because I can load longer.. but in the DI gas gun, Varget gave me the best velocity/accuracy mix. All this to say, load up the heavier bullets as everyone has mentioned and get out the chrony. Your results may vary, but in LC brass, 44.2 varget, Federal GMM primers and Hornady BTHP chronographed at 2740 from my 20" gas gun running a Lothar Walther 1-10 barrel (which I believe really made a difference). It keeps them sonic to 1100yds give or take depending on density altitude. This is break-neck speed for the 178 in a 308 and is rough on brass, so BE CAREFUL. Always load using reliable data and work up watching for pressure signs. Good luck, and happy hunting!
 
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#23
Frank said:
Whats the magic number to stay supersonic? I know the speed of sound is 1126, so is that the number or does the turbulence start as the bullet approaches that speed?
Click to expand...

It varies with Temperature. It will be lower in winter/cooler temps and higher in the summer temps. Run numbers through a ballistic calculator like JBM and modify the temperature.

Folks who load subsonic know this and adjust below 1050fps exactly for this reason. Factory subloads are generally listed around 1050fps, and if the temps drop enough you will get a supersonic crack.
 
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#24
Frank said:
Whats the magic number to stay supersonic? I know the speed of sound is 1126, so is that the number or does the turbulence start as the bullet approaches that speed?
Click to expand...

Reliably supersonic will mean well over the speed of sound that is why palma guys try to get 155s to speeds like 3000 so it is still 1300-1400fps @ 1k.

A 175smk will still fly fairly well at sub sonic speeds, the 168smk will not, that is why people recommend the 175 over the 168.

I try to get 175smk or 178amax over 2650 and accurate @ 200 those are the loads I use on the rare occasion I go to sac valley.

Computer simulations are good but you really need range time to figure out what works and what doesn't.
 
#26
I use 175 SMK, CCI BR2, LC67 match cases, and 43.5 of Varget to get 2667 FPS, but that is out of a 24 inch barrel with a Miculek comp on the end. If you loose 15 FPS per inch, you will be right at 2607 FPS. So it depends on whether you have a fast or slow barrel. My 24 inch tube on a semi auto developes about 12 FPS more than my 26 inch TRG22 barrel, so I think I have a fast barrel, or shorter throat that developes higher velocity..same outcome though.
 
#28
I am shooting the 185 Berger through a 20 in Armalite AR10, 1/11 Krieger obermeyer chamber throated for .010 jump with a COAL of 2.950. ( cut out the 2.5 lede for 1.5 in the process too.) getting these things mag length for an AR10, your going to loose a lot of speed.

Fwiw, my load is the same as the amu, 45.0 Varget. I get 2675 fps. And about 2-3 loads on the case. In the bolt gun (24 in 5R) factory, I can get 2725. Both guns LOVE it. But it's not mag friendly.

Take a 175 and put 43.5- 45.0 Varget under it at mag length and you'll be fine. I use 45.0 ( work up to that of course) or a 190 and 42 ish of Varget or RE15 and that will work too. Don't get too wrapped up in BC and this and that, math isn't life and published numbers are hard to trust. Find a load that works in your rifle with a 175 and up to get the speed to stay above 1200 fps at 1k and it will be fine.

Kevin Thomas--
Ill be at perry this year we got to get together.
 
#29
I think I can give some insight to your answer without trying to hijack or drift the thread too much by saying ... mach is temperature dependent. As a former test pilot and having flown the F-117 Stealth Fighter as one of my test aircraft ... mach at ISA has always been easy for me to remember as it is essentially 1117 fps (+/- 1 fps). To get mach in fps just add 1058 or 1060 to your current OAT. At lower temps 1058 is closer and at higher temps 1060 is. Pick whichever one you want and they should generally be within 2 fps. So at ISA temp of 59F; 1058 + 59 = 1117. For ballistics we generally are more concerned about what happens at the transonic point. Transonic will be .8M on the slow side at 1.2M on the high side. As the bullet will always be decelerating from the high side, 1.2M is the number you should be most concerned about. Individual bullets vary as to their stability characteristics once they enter the transonic region and 1.15 might be what works better for your bullet. However, if you use 1.2M as your starting point, you can't go wrong. That means to get the most accuracy, when truing your POA vs POI, and determining muzzle velocity by the drop at distance - unless you know better, use the 1.2M data. For example, if you are shooting in Iraq with an OAT of 105F, Mach is 1165 fps. If you add 20% to that figure to correspond to 1.2M, that comes out to 1398 fps. For the ease of math, let's round it to 1400 fps. You'll see some folks using 1340 for their transonic speed regardless of temp but I don't subscribe to that theory just because it's so easy to calculate the real number. Besides, take a look at what changing your muzzle velocity 60 fps does to your drop data (the difference btwn using the generic 1340 and the calculated 1400 fps). Taking the crucial shot at 800 yards and 105F OAT using M118LR, that 60 fps equates to a 13-14" difference btwn where you expected it to hit and where it really hits.

Having said all of that, if you are looking for a 1K shot with a .308; try to find a bullet that will maintain stability farther into the transonic region as compared to other rounds.
 
#31
First off- I am a horrible shot at 1k.

With that out of the way you can work up your drop table for a known shooting range.

You know how many clicks to come up or down.

Wind is the wild card for me? Is it 40% of a 10 mph wind? Or 30% of a 12 mph wind? Is the wind the same at 200 as 500?
So a better BC equates to less impact from the wind to push me latterly off of the target and leave me scratching my head... Again

The higher the BC equates to a lot less wind movement between 500-1k.

All things being equal, they to find a high BC bullet to shoot as you can easily adjust elevation for a known range.

I just stink at reading wind and knowing how to dope for wind.

Having a bullet that has 20% less deflection will help get you onto the target.

Does this make sense or do I need a set of turnouts?
 
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#33
your thinking too much man... whats in your mind will have more effect on your hits than any wind or bullet or whatever..

Get out of the weeds... go shoot it with anything and see where your at, then deviate intelligently from there. As you saw on here we all have different means to the end. Works for us. I have used M118LR out to 1k in a 20 in AR10, a 22in M14 and a 24 in 5RM700. worked as well as I did. I could never get the 155's to shoot well in any of my rifles except a NM M1. pick a bullet, work up an accurate load, see if it stays supersonic and go from there.
 
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