What ammo for 600 yds

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[ARCHIVED THREAD] - What ammo for 600 yds

Posted: 5/16/2017 3:43:16 PM EDT

Im shooting in my first 600 yd match in June and need to ask which ammo should I use? My rifle is a 20" A2 with a 1/9 twist. The ammo i have to choose from is IMI 69gr razor or IMI 77gr razor. Will the 1/9 stabilize a 77gr pill out to 600. I only have access for 300yds to test. I also have a small lot (about 150) of Creedmoor 75gr.

Thanks

Posted: 5/16/2017 3:52:51 PM EDT

[#1]

The 69's will be light at 600........... use the heaviest bullet that will stabilize.
Both the 75 and 77's will work out that far.
If you test at 300, you will have no issue seeing if they stabilize..... it'll be obvious if they don't.

(I shot the BHA loaded 75 ammo out to 600 for yrs.... worked great. Though around 7-800yds they ran out of juice).
PS.....I shoot with 1/7.7 Kriegers...... not 1/9's.

The 77 will also work great that far out..............

(The 69's will work, it's just that at 600 they will really get pushed around by the wind.)

Posted: 5/16/2017 3:56:22 PM EDT

[#2]

You'll have to test for yourself to see if 77 grain will stabilize in your rifle. It just might, given that you have a 20 inch barrel.

Posted: 5/16/2017 4:30:38 PM EDT

[#3]

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You'll have to test for yourself to see if 77 grain will stabilize in your rifle. It just might, given that you have a 20 inch barrel.

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This... "some" 1n9's will stabilize a 75-77gr bullet... but that is uncommon.

Also, see if you can find some Aus. Outback 69gr SMK... a lot of people have had very good accuracy with it.

Posted: 5/16/2017 10:04:53 PM EDT

[#4]

77smk and 75gr horn BTHP hand loads can do it easily

77gr IMI, MK 262 Black hills and several other factory loads will do it.

1:9 twist, as heavy as your barrel will shoot. Try a box of Black Hills 69gr SMKs or the Black Hills reman 68gr BTHP.

Posted: 5/16/2017 10:22:08 PM EDT

[#5]

Off-topic comments removed - Eric802

Posted: 5/17/2017 2:11:46 AM EDT

[#6]

Quoted off-topic comments removed - Eric802

Posted: 5/17/2017 2:42:31 AM EDT

[#7]

The 77gr would be best for 600 yards and the only way to know if your 1/9 will stabilize it sufficiently is to shoot them and see.

Barrels all behave differently.

Posted: 5/17/2017 12:27:27 PM EDT

[#8]

Quoted:
Im shooting in my first 600 yd match in June and need to ask which ammo should I use? My rifle is a 20" A2 with a 1/9 twist. The ammo i have to choose from is IMI 69gr razor or IMI 77gr razor. Will the 1/9 stabilize a 77gr pill out to 600. I only have access for 300yds to test. I also have a small lot (about 150) of Creedmoor 75gr.

Thanks

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Try them all, sometimes a 1 in 9 will stabilize a 77 gr projectile. Depends on the muzzle velocity you're getting. If it's accurate out to 300, it'll be good to 600.

Posted: 5/17/2017 12:41:46 PM EDT

[#9]

I'd give 69gr TMK a try too

Posted: 5/17/2017 4:20:59 PM EDT

[#10]

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I'd give 69gr TMK a try too

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I'd like to know if the TMK would work. It is almost the length of a 77gr SMK.

Posted: 5/18/2017 3:29:46 PM EDT

[#11]

Looking myself, how about the Hornady 5.56 ELD 73 gr Match ??

Posted: 5/18/2017 7:30:10 PM EDT

[#12]

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I'd like to know if the TMK would work. It is almost the length of a 77gr SMK.

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Sierra says on their site that it requires a 1:10 or faster twist rate

Posted: 5/22/2017 4:19:10 PM EDT

[#13]

Do not take 75 or 77 gr to the 600 yard line with a 1/9 twist barrel. And testing that at 200 yards, does not mean it's still going to hold ass at 600 yards (learned that one).

69 gr is the heaviest common bullet you will be able to shoot in that barrel. It is plenty accurate still. It will have a little more bullet drop at distance, which is irrelevant since you are shooting at a regulated 600 yard range - so add a couple more clicks and you're done. The only detriment is that it will be more deflected by the wind, and will drift more as the wind varies from shot to shot.

For what it's worth, the heaviest recommended bullet for a 1/9 twist barrel that I know of is the Berger 73 gr.

Posted: 5/22/2017 4:35:46 PM EDT

[#14]

Check your barrel to ensure twist. Is it closer to 1-8 or 1-10?

A 1-9 doesn't stabilize a 77 most of the time.

Are you shooting bullseye or small plates, or big targets like GI E-types?

It might stabilize a Hornady 75. It will probably stabilize a Hornady 75 A-Max if you're single loading (they'll be too long for a magazine).

A Berger 73 should stabilize, but you'll have to verify. A 69 will work, but your feelings will be hurt if you have any full-value wind or if it's gusty.

Posted: 5/22/2017 4:55:03 PM EDT

[#15]

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Quoted:
Check your barrel to ensure twist. Is it closer to 1-8 or 1-10?

A 1-9 doesn't stabilize a 77 most of the time.

Are you shooting bullseye or small plates, or big targets like GI E-types?

It might stabilize a Hornady 75. It will probably stabilize a Hornady 75 A-Max if you're single loading (they'll be too long for a magazine).

A Berger 73 should stabilize, but you'll have to verify. A 69 will work, but your feelings will be hurt if you have any full-value wind or if it's gusty.

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An Amax is longer than the BTHP, so wouldn't a 1/9 have a harder time with it than the BTHP?

And I used to shoot the 73gr Bergers (Black Hills blue box) in high power competition out to 600. They were stable from a 1/9.

Posted: 5/23/2017 12:37:22 AM EDT

[#16]

IMO it will stabilize 77's no problem.

Posted: 5/23/2017 8:03:26 AM EDT

[#17]

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IMO it will stabilize 77's no problem.

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1:9? Based on what? Maybe, but most likely not.

Posted: 5/23/2017 9:48:18 AM EDT

[#18]

The only experience I can offer is with a 1:9 16.5" Remington SPS, I was able to stabilize 75 BTHP and 77 Nosler CC out to 770 yards at 6600' elevation. I believe that I was making hits on steel beyond that but it was difficult to hear or see. Being that you are closer to sea level it might be iffy.

The 68/69 grain bullets work well and you get more muzzle velocity which helps.

Posted: 5/23/2017 10:15:14 AM EDT

[#19]

OP is going to use it in competition -- but didn't state if it needs to be magazine-length (i.e., repeat feeding-firing, like for Rattle Battle or plate racks) or National Match Course, one at a time, slow-fire.

Butner or Stone Bay for NMC will show problems early if his choice doesn't stabilize.

Posted: 5/23/2017 10:21:07 AM EDT

[#20]

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Quoted:
1:9? Based on what? Maybe, but most likely not.

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Quoted:

Quoted:
IMO it will stabilize 77's no problem.

1:9? Based on what? Maybe, but most likely not.

Sierra 77's have a shorter, "fatter" profile than Hornady 75's, and I've also heard that 1/9 can do an okay job with them.

Posted: 5/23/2017 10:25:23 AM EDT

[#21]

They SHOULD stabilize well enough to group good.

They won't be 100% (or may be) stabile so the BC may be compromised slightly but still better than lighter bullets.

For shits and giggles I am going to try some 55gr fmjs and some 77smks out of my crappy 16" M4 1:9 twist to 700yds next week.

According to AB Mobile, using my range conditions @2600fps they will be 1.5SG in my 9 twist which is considered 100% stability.

Attached File

Posted: 5/23/2017 11:56:27 AM EDT

[#22]

http://www.bergerbullets.com/twist-rate-calculator/

According to Berger, a 77 gr OTM at 800' elevation being pushed at a heavy 2800 FPS (load it hot), will have an SG of 1.42 at 80 degrees F. That should shoot just fine. 1.5 is considered definately good. and 0
.99 is considered definitely bad. 1 - 1.5 is considered marginal, and might shoot well, and might not. And that even if it does shoot will, will have a lower ballistic coefficient than book value doing it. 1.42 is pretty close to 1.5, so you should be close. Beware though, if that twist is 9.2 actual, that SG drops.

So what is the "shoot's good" value cut-off below 1.5? Nobody knows, it just depends. I would guess a 1.4 should be OK. In my 1/9 carbine using a mild load of just 2500 FPS due to the short barrel, my bullets were losing it at 600 yards with an SG of about 1.37. So I'd say from experience anything below 1.4 is dangerous ground at long distance (they did good at 200 yards though).

The risk of doing this with 77's is your bullets losing it at 600. The risk of doing it with 69's is if it's a windy day, with lots of wind variability - you will be struggling more. I'd look at wind behavior data, and the range layout. If it's a smaller range with lots of tree's, and winds typically below 10MPH, just take the 69's

Posted: 5/23/2017 12:26:29 PM EDT

[#23]

I've fired 55s at Butner before. I've seen a guy shoot 52 Amax bullets. Lighter bullets will work. However, you'll need to test to really know.

I've had a 1/9 barrel that was actually 1/8 when I tested with a cleaning rod.

Test a few rounds of each if possible before you fire for record. If you cannot test first, take the 69s as a backup.

Posted: 5/23/2017 7:42:53 PM EDT

[#24]

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Sierra 77's have a shorter, "fatter" profile than Hornady 75's, and I've also heard that 1/9 can do an okay job with them.

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Not in any 1:9 ive owned or shot. YMMV

YMMV and all, but has anyone done a test with several 1:9 barrels?

Posted: 5/23/2017 8:10:41 PM EDT

[#25]

Well I guess we'll have to let OP try them and report back, then we'll know.

Posted: 5/23/2017 8:59:19 PM EDT

[#26]

I used to shoot both a rack grade Colt and a high power match specific A2 with 1/7 twist barrels using either Prvi Partizan or Hornady Steelmatch 75 grain. Being you have a 1/9, I'd try Prvi Partizan 69 grain. I was never particularly good at the sport, but found the 75 grain ammo would hold 1.5 MOA from the bench.

Posted: 5/24/2017 6:59:03 AM EDT

[#27]

I am shooting in a CMP EIC match at Talladega Al. I have 2 rapid fire stages so the have to fit in a mag.

Posted: 5/24/2017 10:38:54 PM EDT

[#28]

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I am shooting in a CMP EIC match at Talladega Al. I have 2 rapid fire stages so the have to fit in a mag.

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For sitting and rapid prone, that's true. However, many shooters have rounds for 600 that are seated to be close to the lans.

As you compete, ask the guys around you what they use. Folks at the top of the board are looking for every advantage. Pay especially close attention to their gear, positions, and advice.

Posted: 5/25/2017 12:26:15 AM EDT

[#29]

Quoted:
Im shooting in my first 600 yd match in June and need to ask which ammo should I use? My rifle is a 20" A2 with a 1/9 twist. The ammo i have to choose from is IMI 69gr razor or IMI 77gr razor. Will the 1/9 stabilize a 77gr pill out to 600. I only have access for 300yds to test. I also have a small lot (about 150) of Creedmoor 75gr.

Thanks

View Quote

Sir:
You got all sorts of yes-no-maybe answers.
My suggestion is to shoot the various rounds at 300yds. You need a 300yd zero anyways for prone rapid.
At that distance, you'll get your answer as to what is stable and what isn't.

See you at the TMP........

Posted: 5/31/2017 11:16:57 PM EDT

[#30]

You would be better off playing it safe with the 69gr's until you can confirm that your rifle will shoot 77gr's at 600.

The 69gr's may be more vulnerable to wind, but if your 77gr's are not stabalized by the 1/9 twist at 600 yards, your going to be way, way worse situation. There's really no correcting for an unstablized bullet.

Posted: 5/31/2017 11:53:38 PM EDT

[#31]

To the OP: So, have you tested the 77s at 2 or 300 yet? If it shoots tight at 3, then you should be good. If your barrel won't stabilize the 77s, it would be obvious even at 100yds. It would be shooting like 6-9" groups with possible keyholing. My 1:9 bushmaster 16" will not shoot 77s and that's what it does at 100yd. On the other hand my bushmaster 1:9 HBAR shoots 77s just fine.

Posted: 6/1/2017 7:38:17 PM EDT

[#32]

best bet is get the 69gr OTM ammo.
sight in your gun and get good dope.

Posted: 6/2/2017 12:00:17 PM EDT

[#33]

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Quoted:
IMO it will stabilize 77's no problem.

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Not out to 600yds it wont.

Posted: 6/2/2017 6:50:09 PM EDT

[#34]

69 gr black hills TMK is what I would run if you can't validate beforehand.

Posted: 6/2/2017 7:06:39 PM EDT

[#35]

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Well I guess we'll have to let OP try them and report back, then we'll know.

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Posted: 6/4/2017 11:14:57 AM EDT

[#36]

On the side of the Box for Black Hills M262 they state that a 1:9 or lower is need to stabilize 75 and 77 gr. Whether or not that is just pertaining to their load or others as well I don't know. It's an expensive test possibly but if it works that ammo is definitely worth it.

Posted: 6/4/2017 12:28:19 PM EDT

[#37]

OP,

You'll find good advice from guys shooting EIC matches here:
Arfcom Highpower and CMP forum

And here:

US Rifle Teams forums

IMHO you should try some hot 77gr ammo at distance to establish whether it is stable in your barrel. It sounds like you are trying to use the same ammo across the entire course. You'll find most competitors use specific ammo at each yardage. For example, I shoot 69gr at 200, 77gr at 300, and 80gr at 600. My barrel is a 1:8.

If I had to shoot your barrel across the course I'd try 69gr at 200, and 77gr for 300 and 600. If it's stable. If it's stable at 300 it'll be stable at 600 IMHO because stability is a function of rotational speed, not foreward velocity. And rotational energy is retained much longer than velocity. That's why long-range shooters can fire cigar-shaped bullets a mile and they are still stable when the velocity has dropped all the way down to 1,200fps.

Whatever you do, you need to test your ammo at full match distances. You do not want to start a scored string of fire with "best guess" elevation come-ups. Do whatever it takes to get some 200, 300, and 600 yard range time with your selected ammo so you go into the match with known zeros.

Remove as many unknowns and variables as possible so you can shoot the match calmly with your head on straight. Calm is smooth and smooth is the only way to do your best.

(I'm not an expert, but I did get a CMP gold medal in the mail last week)

Posted: 6/4/2017 1:56:01 PM EDT

[#38]

Get a 1:7 or 1:8 barrel

77gr typically don't shoot well in 1:9

until then, load up some of these...

https://www.sierrabullets.com/store/product.cfm/sn/1380/224-dia-69-gr-HPBT-MatchKing

https://www.midwayusa.com/product/1482224712/sierra-matchking-bullets-22-caliber-224-diameter-69-grain-hollow-point-boat-tail

http://accurateshooter.net/Downloads/sierra223ar.pdf

Posted: 6/5/2017 7:10:57 AM EDT

[#39]

I used the 69gr IMI ammo at 600 yds. I tried the 75gr creedmoor ammo at 600 but my rifle did not like them. With the 69s I shot a 170 out of 200 points it would have been better if I had not turned my windage the wrong way.

Posted: 6/5/2017 3:56:52 PM EDT

[#40]

Quote History

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I used the 69gr IMI ammo at 600 yds. I tried the 75gr creedmoor ammo at 600 but my rifle did not like them. With the 69s I shot a 170 out of 200 points it would have been better if I had not turned my windage the wrong way.

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Great shooting for your first time out!

Did you feel the 75gr's weren't stabilizing or were they just not shooting well?

Posted: 6/6/2017 9:57:49 AM EDT

[#41]

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Try them all, sometimes a 1 in 9 will stabilize a 77 gr projectile. Depends on the muzzle velocity you're getting. If it's accurate out to 300, it'll be good to 600.

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This right here.

Posted: 6/6/2017 12:15:14 PM EDT

[#42]

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Not out to 600yds it wont.

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IF(note: IF), it is gyroscopically stable at the muzzle it will remain gyroscopically stable until transonic speeds, at which point it may lose dynamic stability.

It gets more stable as it slows because the spin decays at a slower rate than the velocity.

Unless he is really slow he should be above transonic at 600yds. My 16" load goes transonic at 700yds in my conditions. A 20" should do better ( assuming it is stable at the muzzle)

Posted: 6/6/2017 7:45:45 PM EDT

[#43]

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Quoted:
IF(note: IF), it is gyroscopically stable at the muzzle it will remain gyroscopically stable until transonic speeds, at which point it may lose dynamic stability.

It gets more stable as it slows because the spin decays at a slower rate than the velocity.

Unless he is really slow he should be above transonic at 600yds. My 16" load goes transonic at 700yds in my conditions. A 20" should do better ( assuming it is stable at the muzzle)

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Quoted:

Quoted:

Not out to 600yds it wont.

IF(note: IF), it is gyroscopically stable at the muzzle it will remain gyroscopically stable until transonic speeds, at which point it may lose dynamic stability.

It gets more stable as it slows because the spin decays at a slower rate than the velocity.

Unless he is really slow he should be above transonic at 600yds. My 16" load goes transonic at 700yds in my conditions. A 20" should do better ( assuming it is stable at the muzzle)

You'd think - but that's not been my experience. Maybe it's due to approaching the transonic zone, which can have instability a good distance from the actual book-value velocity (I don't know why). In my case, I was shooting some mild 75 gr loads, that the shorter barrel shot even milder - and was still technically supersonic at 600 yards, but in practice - not enough. So tight 200 yard ammo lost it at about 500yards for me.

in a 20" loaded to hot velocity, you should have better luck. Should.

Me, I don't advise going to a match with a hope that the ammo works, and not much more. People shot 69 gr bullets at 600 yards in service rifle competition for a long time. It was once the standard. For a new shooter, the frustration of a little extra wind-drift is going to be way less - than this

Posted: 6/7/2017 7:02:49 AM EDT

[#44]

The 75gr shot fine but they did not group as well as the 69gr at 600. Was going to try the IMI 77gr stuff but they closed range 1 early on Thursday and I did not get to them.

Posted: 6/7/2017 11:33:59 AM EDT

[#45]

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The 75gr shot fine but they did not group as well as the 69gr at 600. Was going to try the IMI 77gr stuff but they closed range 1 early on Thursday and I did not get to them.

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Good to know! Thanks for letting me know.................
I've always been impressed with the IMI stuff...................

Posted: 6/7/2017 11:35:42 AM EDT

[#46]

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Me, I don't advise going to a match with a hope that the ammo works, and not much more. People shot 69 gr bullets at 600 yards in service rifle competition for a long time. It was once the standard.

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Agreed.

This weekend I was hoping to try my 16" 1:9 with the 77s out to 1060 (500, 600 or 700 really, farther maybe) but it was pouring rain.

Mud was so bad I had to hike to the range a mile and a half uphill in the rain carrying 80lbs of rifles, ammo and gear. No way was I going to add another 8lb rifle plus ammo that might not work, too old for that shit LOL. Next trip I'll try it.

I shoot single feed 90SMKs to 1060 with my 18", they actually work well out of my 7twist, I have read other report they don't do well at long range. Different barrels do different things I suppose.

Posted: 6/8/2017 2:29:02 PM EDT

[#47]

For the 1-9 barrel, the Barnes Match Burner 69gr are slightly longer than comparable bullets, but will stabilize. that little bit of extra length improves downrange stability a bit, so if you load that might be the best solution.