One range trip, two rifles, a stack of questions.

[Pond James Pond]

I went to the range today and over the course of 2.5 hours, I zeroed my AR Leupold at 50m, shot both my AR and my .308 bolt at 100m and tried my hand for the first time at 300m, again with both.

I am a quite pleased with the results, but I have a few questions.

The gear and the conditions:
First about the guns and the ammo. The AR is a new M400 Sig and today I put bullets 101 to 160 down the barrel. It is also the first time I've shot it with a scope.

The .308 is known to me, but this was the first time I had shot the Finnish milsurp I was feeding it today. The .223 sped the 55gr BT bullet along at about 2980fps, whereas the .308 managed 2680fps. I don't know the bullet weight, but I am guessing 155-167gr based on the velocity and recoil.

Weather was dry, clear, the air was still and it was not too cold.

50m:
The AR zeroed quite easily, and in the end, seated and resting the handguard on a firm surface, I shot a 1" group. Not brilliant, but even at 50m and 4x I was having difficulty with detail recognition on the target which was a 10 ring target with zones 7-10 all black.

100m:
At 100m, I shot the .308 first, prone, with a bipod. I fired 8 shots, and they all went up (about 8") and left (about 1-2") when aiming at the centre. They grouped OK, but nothing more. The group was about 2" squared, with 2 shots touching, another pair close nearby and another cluster of 3. 1 was nowhere near. So in all with the same POA, I seemingly had 3 little clusters all together.
My shooting didn't feel bad: I didn't feel like I was flinching and the trigger break came smoothly.

With the AR, I assumed a kneeling on one knee position, and fired relatively fast. As soon as my sights were back on I squeezed. Frankly I was having a bit of fun as I was confident of the AR's accuracy so I was not expecting a tight group and I didn't get one!! The strikes were pretty much spread over the whole target, but with a heavier concentration around the 10-9 rings, so not great, but was not being as precise either.

300m:
It is the 300m that bothers me.

These were shot prone for both guns. The .308 was still a bit high, but only by an inch or two, and the 12 shot group was almost all in the 8-9-10 rings, but showed more horizontal spread (about 10") than vertical (about 6"). I was on max magnification at 12x and I was aiming dead centre. As above, I thought my shooting felt OK, and it was my first time.
Then came the Sig. They gave me a rifle clamp to help me as only prone is allowed at 300m and I had no bipod for the Sig. Only one shot on the paper. All the others looked as though they'd struck the ply board the paper was on. They were fairly widely spread, but all there, as far as I could tell

Needless to say, small detail on the target was negligible with the 4x, but I knew if my cross-hairs were on centre and between the prone position and the rest, a good cheek-weld and my other hand supporting the stock, I did not feel remotely unsteady.

With a .223 at almost 3000fps and a 50m zero I was expecting the hits to all be reaching their second zero point, or on the target at least, but all hits must have been about 12" below the 10-ring POA and horizontally spread a good 8". Disappointed.

AR:
So, based on those descriptions, what could it be?

My rifle is somehow defective?
The scope is badly set up?
My shooting is crap?
All is normal for this type of gun?

I don't expect it to be #4, and I sort of hope it is #3 as it's the easiest to address and doesn't mean I've bought a lemon!

.308:
Does this sound like milsurp accuracy or is it particularly bad?

Pictures to follow when possible

 

[Pond James Pond]

Here are the pictures of the targets.

First the 50m target. Target was stapled upside down!
The zero groups were on the vertical white numbers directly above the bullseye. Another test group was just bove the bullseye: looks like grey holes, and another loose cluster around the bullseye.

Then 100m.

Finally the 300m.
Note the sole .223 hit near the paper's edge at about 7 o'clock.

 

[Panfisher]

I doubt you have a lemon of a rifle, your shooting technique may need improvement (mine too). A lot of it may well be ammo specific I have noticed in my AR that it much prefers flat base bullets to boat tails. It shot 55 grain Nosler Varmageddon bullets noticeably better than the same weight of Nosler Ballistic Tips (wich are boat tailed slightly), and shot the Barnes Flat Base 55 grain hollow points better as well. For me it would be tough to shoot accurately at 300 meters with a 4x scope, especially as my AR doesn't have a nice crisp trigger, hence the reason my AR has two scopes a 1.5-4.5 Bushnell and a 3-9 Leupold. In my mind for a sporter weight rifle, with a 4x scope and no experience with the platform you may not be doing to badly, practice is always a good thing.

The .308 I certainly wouldn't expect a lot out of mil-surp ammo unless you were lucky enough to find one it really likes. Check the mounts and rings to make sure both are tight, I've been guilty of failing to get thim properly tightened on more than one occasion.

 

[Pond James Pond]

I doubt you have a lemon of a rifle,

I am very happy to read that. i hope you're right. What bothers me though is that while the group was quite loose, which can be put down to me the shooter, it is the positioning of the group I find alarming.

My reticle was very steady in that rifle rest and it was dead one centre and stayed there when the trigger broke, yet all hits were off the paper.
At that range, that is the sort of bullet drop from 7.62x39, not .223.

 

[spacemanspiff]

Would need to know what ammo you had for the AR. Was it .223 or 5.56, and was it 55 gr, 62 gr or something else?

Also, was there a reason you didnt shoot prone at 50 or 100 with the AR? If it were me, I would want to be able to compare apples to apples. If I shoot offhand at one distance, I'd like to see how I shoot offhand at a greater distance. If prone at one, see what I can do with prone at another.

 

[Pond James Pond]

Would need to know what ammo you had for the AR. Was it .223 or 5.56, and was it 55 gr, 62 gr or something else?

.223, 55gr BT.

Also, was there a reason you didnt shoot prone at 50 or 100 with the AR? If it were me, I would want to be able to compare apples to apples. If I shoot offhand at one distance, I'd like to see how I shoot offhand at a greater distance. If prone at one, see what I can do with prone at another.

Prone at 50yds was not possible: shooting from a cabin. Prone at 300 was compulsory. At 100, I was just shooting the AR for a bit of fun. I was really interested in seeing if a zero at 50 would yield zero or near-zero again at 300m.

 

[MrBorland]

With a .223 at almost 3000fps and a 50m zero I was expecting the hits to all be reaching their second zero point, or on the target at least, but all hits must have been about 12" below the 10-ring POA and horizontally spread a good 8".

I'd expect your 300m POI to be significantly lower than your 50 yard zero. Your 55gr bullet likely has a BC of .20ish - about half the likely BC of the .308 bullets you were shooting. Go to an on-line ballistic calculator and plug in your .223 data. If you use that BC, your MV of 2980 fps, and a 50 yard zero, you'll get a predicted 11" drop at 325 yards (approx 300m), which is just about what you're seeing.

As to your group size, it's likely half you, and the other half the ammo and the rifle.

My rifle is somehow defective?

I'm sure it's an ok rifle, but in my (albeit limited AR) experience, it's asking a lot for a factory tactical carbine to deliver 300m match-grade accuracy, especially with 55gr ammo. You might try some 69 grain ammo. It's got better ballistics, and the specs on your rifle indicate a relatively fast twist that ought to do ok with heavier bullets.

 

[1stmar]

Are you sure about the weather conditions ? No wind? Maybe a 5mph right to left? How was your trigger control?

 

[Snyper]

It may be you miscalculated the ballistics of the load
Also, not all rifles will be accurate with all loads, so it's far too soon to worry about tight (or not) groups

I'd also get some Birchwood Casey Target Spots to give you a much more precise aim point

 

[precision_shooter]

Plugged in the numbers in the Hornady ballistic calculator...
With a 50yd zero, those .223 rounds will be almost 14 inches low at 300yds.

How big are the targets you are shooting at, from center of bullseye to bottom edge? Where the 1 round struck looks to be 12-14 inches from the bullseye...

How were the wind conditions? Speed, direction in relation to the shooter?
Those little/light 55gr bullets only have a BC of around 0.24x, so they will be effected by wind a lot more than the .308.

Seems to me that you just need more practice with wind drift for different rounds. Not a bad thing... Plenty of people, myself included, have not mastered the art of wind doping...
Might help to have a spotter with you next time to call your shots so you're not left wondering where the rounds went or chasing anomalies that might not be anomalies...

 

[Pond James Pond]

Plugged in the numbers in the Hornady ballistic calculator...
With a 50yd zero, those .223 rounds will be almost 14 inches low at 300yds.

Now that is useful information!! Thanks. But it does fly in the face of what I've previously read.
If .223 is so flat shooting why am I getting 14" drop at 300m and not 4" (see below)!!

Discussions with other shooters, and info on here suggested that with a 50m zero, I'd have the second zero as the bullet starts drop down again between 250 and 300m. Is this not the case?

As I said before, this sounds more like 7.62x39: not very flat shooting!

Looking at this pdf presentation, scrolling down to the silhouette comparison page where different zeroes and their subsequent POI colour coded for different distances, a 50m zero suggests a 4" drop from the zero line. That is very different from my results.

My velocity about 7yds from the muzzle was about 2980fps, so these are travelling at normal .223 speeds.

The bullets all hit around the same level, so the bullet drop is consistent, but why is it there?

Can someone clarify?

PS targets were blocky head and CoM size targets with scoring rings. About 70-80cm squared. The silhouette is clearly visible at all the above distances,

 

[Jimro]

Nato spec for 7.62x51 is generally a 144 to 150gr boat tail full metal jacket between 2,700 fps and 2,800 fps.

I say "generally" because there are exceptions. The BC for those projectiles in 308 is generally around 0.4 in the G1 referrence.

I expect 3 minute or larger groups from any surplus 7.62x51, even out of a precision rifle. So your experience is in line with my expectations.

The added horizontal spread is nothing to worry about at 300 meters since you held dead center for each shot. Wind conditions will give you that added horizontal spread, so your vertical spread is a better indicator of potential performance.

Hope this helps,
Jimro

 

[Pond James Pond]

The added horizontal spread is nothing to worry about at 300 meters since you held dead center for each shot. Wind conditions will give you that added horizontal spread, so your vertical spread is a better indicator of potential performance.

That is helpful. After all, I probably have about 200 rds of .308 under belt, total. And those 12 shots at 300m are my complete "long range" experience!!

I think they are acceptable as a plink load. Given that I can buy them for 25% less than a S&B .38 Spl WC, I think I can live with the poorer accuracy for a tripling in shooting time!!

I spoke to my club owner about the .223 performance and he seems to think it is not beyond the realms of possibility, but all this gave me an idea for a new thread too!!

 

[MrBorland]

Now that is useful information!! Thanks. But it does fly in the face of what I've previously read.
If .223 is so flat shooting why am I getting 14" drop at 300m and not 4" (see below)!!

Not all .223 bullets are the same. If you're gonna stretch it's legs, you might do better with heavier bullets for their better BC.

Discussions with other shooters, and info on here suggested that with a 50m zero, I'd have the second zero as the bullet starts drop down again between 250 and 300m. Is this not the case?

Looking at this pdf presentation, scrolling down to the silhouette comparison page where different zeroes and their subsequent POI colour coded for different distances, a 50m zero suggests a 4" drop from the zero line. That is very different from my results.

I'm not seeing any pdf, but it's likely the apex of the trajectory used in the silhouette trajectory was set to be somewhere between 50m and 300m, so the bullet passes closer to zero at 50m and 300m.

I suspect in your case, though, you set a true zero at 50m, meaning the apex of the bullet's trajectory was set at 50m.

 

[Pond James Pond]

I'm not seeing any pdf, but it's likely the apex of the trajectory used in the silhouette trajectory was set to be somewhere between 50m and 300m, so the bullet passes closer to zero at 50m and 300m.

Here's the link. I know it is generic, but between this and the general internet wisdom surrounding .223's flight path, I thought I'd be closer to this than not.

If you're gonna stretch it's legs, you might do better with heavier bullets for their better BC.

Well, price sort of makes my existing choice the only choice for now. Really, I just want reasonable reassurances that it is not my new rifle. Personal ability, bullet choice, scope adjustment: these are all things I can work around, or improve. A dodgy gun, would be much harder!

 

[MrBorland]

Here's the link. I know it is generic, but between this and the general internet wisdom surrounding .223's flight path, I thought I'd be closer to this than not.

Pages 20 and 39 are exactly what I was referring to in the last 2 lines of my previous post. When "zeroed" at 50 in this example, the bullet's going through a zero 50 on it's way to its apex (around 175 yards), and it passes through 300, relatively close to zero, on its way down.

I think what you're doing is setting a true zero at 50m, meaning you're setting the apex much closer, right at 50m, so the bullet's going to hit much lower at 300m.

IOW, if you want your 50m and 300m to be close to zero, you have to sight in several inches high at something like 175m. I suspect your issue's not as much a ballistic issue as simply a scope setting issue.

 

[Pond James Pond]

I think what you're doing is setting a true zero at 50m, meaning you're setting the apex much closer, right at 50m, so the bullet's going to hit much lower at 300m.

Hmmm. A bit confused about that when I wasn't before!! Knowledge is a dangerous thing!!

The way things are at the moment, my line of sight through the scope put the target centre in the centre of my duplex reticle. the muzzle was about 1.5" below and about 15" forward of that. I set it up so that when the bullet hit the target it hit the same point as where the reticle was aimed.

At 100m, al the hits were centred around the 10 ring, in terms of vertical spread (as seen in the second pic). Some above, a few more below.

How do I know if the bullet has apexed or not @50, and if that is the case using my technique, how do I reproduce what was on page 20/39 of that presentation?!


(when I first started shooting I just thought you had to pull the trigger that that was it!!)

 

[MrBorland]

How do I know if the bullet has apexed or not @50

If your groups were nice and tight at 100, you could see if they were a little higher than 50, or a little lower. They weren't tight enough to tell definitively, though. Next time, if you're able, (carefully) shoot at 200m. If you zero'd like in the pdf, the rounds would likely hit high. I suspect you'll see they hit a bit low, though, which shows you set your true zero at 50m.

 

[Pond James Pond]

Between my aim, my scope magnification and the fact there is no 200m range eek, all that may be a bit hard to check!!

What I could do instead is go back, try to tighten up my 50m groups, then go to the 100m range I shoot there, but with an emphasis on precision rather than fun and see where they end up. Ideally about 4" high or so...

 

[MrBorland]

I was at the range today, and just happened to be shooting my AR15 at 300 yards, so, just for you , I shot a group at 50 yards, leaving the sights as they were, and the shots hit about 2" high, just about what you'd expect if I was dead on at 300 yards.

Sounds like you're hitting about 14" low at 300m with a 50m zero. Theoretically, you want to be hitting about 4" low at 300m to give you a 50m zero. So you need to come up 10" over 300m, which is 3MOA. Assuming your scope is 1/4 MOA per click, add 12 clicks in the "up" direction. Confirm you're hitting about 4" low at 300, then see how you do at 50. You ought to be pretty close to zero.