Effective Range of 16"BBL .308?

[sigmundsauer]

shivan,

Your point is well taken. Although, being able to "hold-over" a target to effect a shot is not the same thing to me as "effective range." Can you reasonably predict a hit to effect a kill at 300m? Yes, maybe at your skill level. The shot you described would normally be considered beyond the capability of the average shooter, and would rely on optics. If I had the shot I would take it but in the knowledge that it is beyond the effective range of the gun, assuming irons.

A 200 yard zero is on the "high side" for a 16" .308 IMO but would make 250m shots relatively simple, IMO.

A 16" .308 is generally going to generate modest velocities of 2400-2700 fps. I think that puts it at a 250m battlesight at max. Just my criteria. No one else's.

As a comparison. An M4 graded at a max effective range of 550m is normally zero'ed for 300m with a trajectory that pitches M855 9-10" above bore line. That's pretty steep and sacrifices precision at mid-range targets regardless of iron or optic. I think it's pushing the limits at velocity of ~2800 fps.

Tim

[KevinB]

Irons and Battlesight
Optic...

S&B Short Dot with the M118LR BDC for the 16" SR25 makes it a good 400m gun easy - and 600m if you have the time.

[SHIVAN]

That's what I've been trying to say....

[sigmundsauer]

Irons and Battlesight
Optic...

S&B Short Dot with the M118LR BDC for the 16" SR25 makes it a good 400m gun easy - and 600m if you have the time.

Iron....sights?
Battlesight.....zero?
Optical....sight?

Sheesh, are these foreign terms? I've lurked here long enough to know better....i think.

However, last time I checked "effective range" is a distinctly military term with a specific connotation. Are we trying to answer a question about what one CAN do with a carbine or what it's "effective range" is? Clearly the former, not that there is anything wrong with that.

BDCs and sophisticated optics can increase hit probability with many weapons, but now we are getting out of the scope (pardon the pun) of what a typical marksman and a typical carbine are intended and capable of doing for general field work. ...but yes a Short Dot can maximize the utility of any carbine, although a rather scarce piece of equipment inside and outside of the military.

Just my $.02

Cheers,
Tim

[KevinB]

Really I would not know

My point is that you are basis your term effective range based upon the "book Value" of a CCO or Iron BZO.

With an ACOG even which is relatively common for regular troops, any half baked idiot can now range (no offence to half baked idiots).

Engagement at distance is not black art - provided you can detect the target and see you rounds impact (hence why mag optics come into their own past 200m).

Effective Ranges are typically broken down for mil terms between area and pt. targets - to the point that you will get a point effective range @ X and the area effective range past that.
This takes a rough concept for commanders to base their engagements on.

I was going to say bylarge I've never met anyone that cannot engage a pt/ target out past the book value, but in interaction with other units one can see how low the bar can be.

However given a 16" 7.62mm gun is more an Urban DM setup I figured I'd based the Effective Range discussion based upon a fair shooter with a decent setup, and in that respect the iron and BSO issue is moot.

[Dave L.]

(no offence to half baked idiots).

......None taken

[sigmundsauer]

Really I would not know

My point is that you are basis your term effective range based upon the "book Value" of a CCO or Iron BZO.

With an ACOG even which is relatively common for regular troops, any half baked idiot can now range (no offence to half baked idiots).

Engagement at distance is not black art - provided you can detect the target and see you rounds impact (hence why mag optics come into their own past 200m).

Effective Ranges are typically broken down for mil terms between area and pt. targets - to the point that you will get a point effective range @ X and the area effective range past that.
This takes a rough concept for commanders to base their engagements on.

I was going to say bylarge I've never met anyone that cannot engage a pt/ target out past the book value, but in interaction with other units one can see how low the bar can be.

However given a 16" 7.62mm gun is more an Urban DM setup I figured I'd based the Effective Range discussion based upon a fair shooter with a decent setup, and in that respect the iron and BSO issue is moot.

KevinB,

I suppose we're turning this thread into something much more complicated than originally intended. I'm tracking with your reasoning, except that I would reemphasize that the military's definition (book value) of effective range of a weapon (point or area) is a combination of hit probability and penetration/energy on target to determine max range. This "effective range" is not a sliding scale based off of the marksman's (in)ability. If one can attain shots beyond the normal range of the weapon it is either above average skill or luck or both. It is only in recent years that common infantry have been equipped with better tools to increase hit probability at greater ranges. ACOGs, Short Dots and other glass are great tools, but we still haven't seen a material improvement in the actual marksmanship skills of our armed forces beyond CQB distances. But that's a whole 'nother discussion.

I agree with you, that I and most other marksmen socializing here at m4carbine.net are in all probability not the "average marksman" that the military factors into their "effective range." Most of us could reasonably attempt and achieve shots beyond 200m with a 16" .308 of known zero and power really isn't the issue at these intermediate ranges. Given that a 16" .308 is still not a standard issue military weapon, speculating on its "effective range" is really more a discussion about what can be done with the carbine more than what it was designed to do. Because Carlos Hathcock has made 1000+ yard shots with a .308 doesn't redefine the effective range of the weapon, it just means that he compensated for the weapon's inherent performance attributes and other conditions (did everything right).

Tim

[Armati]

I am not sure where this thread is going, but I sort of have the same question.

I would like to build a 16" .308 into sort of an urban DM gun. I was looking at doing a Saiga conversion or building up a FAL para with an 18" bbl.

My only expectation is to hit center of steel plate a 500 - 800m.

What will I lose in terms of velocity? What kind of bullet drop can I expect? Are there ballistic tables for 16" - 18" bbls? My thinking is that I would need to chrono the MV of my particular set up and then run the ballistic calculations.

As for optics, I have an old .308 ELCAN lying around. Not the best but I don't have to pay extra for it! Again, I think hitting minute of man is the best I am going to get.