How far will 5.56mm travel?

[Eurodriver]

Out of a 20" AR15 firing 77gr TMKs at 2750FPS on level terrain at <50ft above sea level - how far will the bullet go?

Let's assume, for fun, A: You are trying to achieve the absolute furthest possible distance - pointing the rifle at about a 45* angle and mortaring the bullet.

But also more to the point of the thread B: If you are hunting in such an area and take a shot at game and miss - how far is that round going to go?

I know 5.56mm after about 600 yards starts dropping a few inches (see below) for every yard the bullet travels. Under condition B: Is there any possible way that barns/structures 4 miles away would be in any danger at all?

[Inkslinger]

I think it's 3600m.

ETA: tried finding the manual I saw that in, but my google-fu is failing me.

[Failure2Stop]

DA-PAM 385-63 lists all adopted ammunition types safety distances (you can even learn how to draw SDZs!).
It does not, however, contain the information for AA53 (Mk 262 Mod 1) since AA53 isn't officially adopted Army ammo.
That said, Mk 262 easily fits inside M118LR, which has a theoretical max distance (distance x) of 5,288 meters, which is fairly shy of 4 miles.
I believe that Mk 262 is actually closer to 3,800 meters, depending on altitude.

[Ned Christiansen]

"After about 600 yards starts dropping a few feet for every dozen yards the bullet travels".

I checked this some years ago, wanting, like you, some idea of what would happen if I put one over the backstop. I found more like 1" per yard, and that might have been after (AT, actually) 1,000 yards (but it mighta been after 600). Either way I believe the above in incorrect on the high side.

[Eurodriver]

F2S, I'm assuming those max distances are basically arcing the rifle at an insanely steep angle? Something one wouldn't do in a flat state like FL unless shooting at a BG from the ground into an elevated building or something of that nature?

I could, and may be, totally freaking wrong on all of this of course. I'm mostly just thinking out loud because I'd like to know just how far to "Be sure of your target and what lies beyond it". This all stems from a shot at a deer where I was prone and the deer was somewhat skylined by a slight rise in elevation. My barrel wasn't even remotely pointed upward, but seeing nothing but sky behind the deer made me wonder how far the round would travel (there was a road about ~1.5 miles behind the deer) given the angle of the barrel. I'm having trouble trying to articulate what I'm trying to ask, but basically it's this:

When you are aiming at a target 1000 yards away, especially with 5.56mm, you've got your scope dialed way up. This angles the barrel (and trajectory) upward creating a rainbow-like trajectory so the bullet can reach the target. Per the below quote with Ned, at 1K, it is about 1" per yard of drop. So if you're aiming at a target that is at 1000 yards and it is 15m above the ground (way high for FL) that bullet is going to impact the ground with 100% certainty within 50m +/- of the target. I'm not sure how far a 5.56mm bullet travelling subsonic will skip along the ground, but you're sure as shit not going to be hitting anyone several miles away.

With a 300y dope on your optic, I'd imagine the danger zone of the bullet would be even less as your rifle is pointed more in line with the horizon and the bullet isn't capable of traveling as far. I have seen people shooting at 100 yard paper targets and their bullets impacted the ground around the ~450 yard mark - but I'm unsure how much the paper had an effect on that.

Am I way off base?


"After about 600 yards starts dropping a few feet for every dozen yards the bullet travels".

I checked this some years ago, wanting, like you, some idea of what would happen if I put one over the backstop. I found more like 1" per yard, and that might have been after (AT, actually) 1,000 yards (but it mighta been after 600). Either way I believe the above in incorrect on the high side.

You're absolutely correct. I checked my data and I was thinking at 300BLK trajectories. My load, according to the calc, drops 63 inches between 950 and 1000 yards - almost 1" per yard and that is at 1K.

[markm]

When you are aiming at a target 1000 yards away, especially with 5.56mm, you've got your scope dialed way up. This angles the barrel (and trajectory) upward creating a rainbow-like trajectory so the bullet can reach the target. Per the below quote with Ned, at 1K, it is about 1" per yard of drop. So if you're aiming at a target that is at 1000 yards and it is 15m above the ground (way high for FL) that bullet is going to impact the ground with 100% certainty within 50m +/- of the target. I'm not sure how far a 5.56mm bullet travelling subsonic will skip along the ground, but you're sure as shit not going to be hitting anyone several miles away.

No doubt. Even with 175 gr SMKs... they're dropping out of the sky for me at 1000 yards and beyond. I can't imagine a 77 gr maintaining stability to a mile.... it doesn't have much ass left in it at 1000 yards. At miles away and unstable, it's likely to bounce off or barely lodge into a wooden structure.

[Kansaswoodguy]

I looked at my dope for 75gr going 2650 at 600 yards they are dropping about 6" for every 10 yards traveled progressively gaining more drop as the bullet slows. I've found 75gr bullets shot at my 700yd target that missed the steel and hit the ground that absolutly looked like I could reload them a second time they where in such good shape. At 1000yds they are dropping 20" for every 10yds traveled and have 145ftlb of energy left. At 1500yd they are dropping 50" for every ten yards traveled moving at 750fps and have 94ftlb of energy if and its a big if they haven't destabilized already. I read an article a while back of a guy taking 223 to a mile he was I think shooting 85gr or 90gr bullets that didn't destabilize when dropping threw the sound barrier. I know the 75gr bthp match bullets destabilize at the transition I would assume the 77gr serria's do also. The 75 Amax don't destabilize and you can play with targets beyond the sound barrier limit. I would guess your 77gr are destabilizing at about 800 yards or so assuming they don't make the transition from super to sub sonic. It's possible they might I haven't played enough with them at those ranges to know for sure.

[markm]

We shoot the 77s through transonic all the time with no issues. We don't get a lot of wind... and wouldn't try the shots if the wind was kicking anyway.

I don't get this X drop for every Y yards traveled. Drop is not linear. The drop is exponential as the distance increases.

[Eurodriver]

We shoot the 77s through transonic all the time with no issues. We don't get a lot of wind... and wouldn't try the shots if the wind was kicking anyway.

I don't get this X drop for every Y yards traveled. Drop is not linear. The drop is exponential as the distance increases.

For sure, but just making an observation based on a general distance.

I.E. if you're aiming (accurately and precisely) at a 1000yd target level with your shooting position with my load and miss - your bullet isn't going to keep traveling miles and miles. It'll land inmediately next to, behind, or in front of the target most likely.

I'd love to go somewhere without much wind. Shooting at 1k is a bitch in .223 because it goes transonic around 920 according to the calc and they just fly all over the place at a grand. The wind at my range is always blowing and it will go from 90* at the firing position to 270* at the target and literally swirl vertically from 600-1000 due to the terrain. Sucks

[drtywk]

For what it is worth, there are confirmed hits on steel around the 1380 yard mark with Hornady 75gr TAP during a scoped carbine course taught by Follow Through Consulting. There are some holdovers involved, but it is possible.

[Failure2Stop]

F2S, I'm assuming those max distances are basically arcing the rifle at an insanely steep angle? Something one wouldn't do in a flat state like FL unless shooting at a BG from the ground into an elevated building or something of that nature?


It's based on the worst case scenario for building open-space training ranges (no back-stop) with a 1:1,000,000 probability of escapement.
It involves the muzzle being at a ~45 degree upward angle (IIRC, it's not a perfect 45 degrees, but it really doesn't matter) for "Distance X" determination.

In the situation that you quoted, the full travel is probably going to be 1/2 to 2/3 of max range.

[Kansaswoodguy]

We shoot the 77s through transonic all the time with no issues. We don't get a lot of wind... and wouldn't try the shots if the wind was kicking anyway.

I don't get this X drop for every Y yards traveled. Drop is not linear. The drop is exponential as the distance increases.

Good to know the 77's do make it threw transonic. I will need to buy a couple hundred and play with them, good stuff in this thread

[soulezoo]

This thread reminds me of a scene in Lonesome Dove.

[Failure2Stop]

This thread reminds me of a scene in Lonesome Dove.

I might be taking that as more positive of a comment than intended, hahaha.

[markm]

For what it is worth, there are confirmed hits on steel around the 1380 yard mark with Hornady 75gr TAP during a scoped carbine course taught by Follow Through Consulting. There are some holdovers involved, but it is possible.

We've tried firing 77s out to 1300 yards, but without a forward observer, it's impossible to pick up any gong strikes... and dirt strikes are just as hard to see. .308 is pretty challenging to call too. I bet we lose 30-40% of our shots with .308.

[soulezoo]

I might be taking that as more positive of a comment than intended, hahaha.

Neither really and wasn't being snarky. There is a scene about in the middle of the movie where Gus was on a plain being chased by bad guys. He had to put down his spent horse and use him as a shield. The bad guys were mocking him at a distance they thought safe. Gus had a Henry rifle. A .44 Henry rimfire wasn't what you would call flat shooting. Gus put the ladder sight all the way up aimed at the sky and lobbed a round into a bad guys gut. That was preceded by him throwing a few rounds short to give them false sense of security.

[Koshinn]

It's based on the worst case scenario for building open-space training ranges (no back-stop) with a 1:1,000,000 probability of escapement.
It involves the muzzle being at a ~45 degree upward angle (IIRC, it's not a perfect 45 degrees, but it really doesn't matter) for "Distance X" determination.

In the situation that you quoted, the full travel is probably going to be 1/2 to 2/3 of max range.

IIRC, the optimum angle is 30-32 degrees. Without wind resistance it would be 45 degrees, but the Earth isn't a vacuum.

[ST911]

We've tried firing 77s out to 1300 yards, but without a forward observer, it's impossible to pick up any gong strikes... and dirt strikes are just as hard to see. .308 is pretty challenging to call too. I bet we lose 30-40% of our shots with .308.

I've seen 77 TMKs and Mk262 hit at 1600, but it took some time to walk them in and good spotters.

Shooting 62s at 1000, I felt like a mortarman.

[Failure2Stop]

Neither really and wasn't being snarky. There is a scene about in the middle of the movie where Gus was on a plain being chased by bad guys. He had to put down his spent horse and use him as a shield. The bad guys were mocking him at a distance they thought safe. Gus had a Henry rifle. A .44 Henry rimfire wasn't what you would call flat shooting. Gus put the ladder sight all the way up aimed at the sky and lobbed a round into a bad guys gut. That was preceded by him throwing a few rounds short to give them false sense of security.

That is a really solid scene.
Reminds me that I need to watch Lonesome Dove with the son soon...

[markm]

I've seen 77 TMKs and Mk262 hit at 1600, but it took some time to walk them in and good spotters.

Shooting 62s at 1000, I felt like a mortarman.

Ah yeah. That's like my 12 twist 308 trying to shoot 168s to 1000. They fan out all over the hillside. There's a landfill out near use with massive, clear dirt embankments that would be PERFECT for gong placement. You could pick up dirt poofs from a mile out. I don't imagine they'd buy off on me hanging steel there however.