trouble hitting past 400 yards

[jvr]

shooting 308 / 20 inch barrel varmint contour / 168 sierra matchkings (factory) / chronoed at avg 2923 / ap ballistics software / 2 spotters / 0 to 10 gusts quartering

i have always wanted to shoot at distance and finally found a 800 yard range. The gun is zeroed at 50 yards. plugged in data for 400. spotted low right; adjusted; dead center 18 inch plate. dialed up the dope for 800. 20 feet right; low. dialed corrections; 3 feet left; 1 foot high. (thinking this long range stuff rocks). dialed in the corrections. dead on low. left; right; high; low everywhere but on the target. darn if i did not run through a box of shells and never touched the 24 inch plate.

lucky at 400? I have shot to 500 with this gun with cheap ammo and lessor scope. could not get to 800 then so I bought a better scope (old scope was fine; but wanted a new toy) and ammo.

does the wind make that big of an effect at another 400 yards?

 

[Trigger Monkey]

I'd check your chrono numbers, 2900+ fps is smokin' for a .30 caliber 168gr SMK in a 20" barrel. Why is your rifle zeroed at 50 yards? No matter, I'd get your zero good to go at 100 yards, double check your chrono data and build your dope from there...your actual dope going on out to 800 yards. Other than that I'd chalk up your experience to inexperience but hey it's the range trips that don't go so well that teach us the most. Have you had any formal instruction?

 

[summy]

Short answer, yes. I plugged your data into Sierra Infinity 6 with my atmospherics (2700' 65 degrees 80% humidity). At 400 yards with a 10 mph quartering wind (I called it half value, or from 1:30) you have 8.71 inches of drift. At 800 you have 41.62 inches of drift with the same wind. If you misjudged the wind and it was actually 15 mph you have 62.56 inches of drift. If you're shooting in a variable wind without correcting for each wind you shot in then its not surprising that you were both sides of the plate.

I'm sure someone else will be along shortly to give you pointers on form, sight picture, and anything else that might be your problem. Goodluck!

 

[walt willis]

It is very rare to be able to shoot out to mid or long range with factory ammo.

You should first be able to shoot a one inch group at 100 yards first before attempting to go out to 300 or 400 yards.

Wind may become a factor past 300 yards, but the greatest concern is your group size at 100 yards.

There may be a factory load that your rifle will do well with.

Try many brands and if they don't work, then find a friend that shoot well and loads his own ammo to help you find the right ammo load for your rifle.

It can be done!

 

[chevytruck_83]

Assuming your shooting a quality rifle hits on your stated 24" target at 400 yards should be no trouble at all with quality match ammo. Ex black hills or federal gold. Whats the make and model of your rifle and twist rate? My guess is you just need more range time to hone your skills. You could hold center on a 24" plate with 10mph wind and still hit a 24" target assuming your drop chart is good.

 

[TacticalBoltKnob]

168 SMK is not a good choice for long range.
Also, your velocity readings are wrong. No way factory 168 MSKs are going over 2900 fps.
Zero at 100 yards, not 50.
Get better velocity data.
Learn to read wind.

 

[Pinecone]

Federal says 168 gr FGMM is 2650 at the muzzle. And that is probably with a 24" barrel. Federal Premium Ammunition - Rifle

No way is your 20" barrel putting them out at 2900+fps.

At 800, what was the wind doing at the target? Mid point between you and the target? There is more to it than the wind at your shooting position. We were shooting at Dan Newberry's Bang Steel class at 1200 yards. Wind at the shooting position was about 10 right to left. Midpoint was about 15 LEFT TO RIGHT, and at the target near 0.

 

[fargo007]

I'm not saying this just because I own a training company, but for the relatively modest fee a lot of the well reviewed training schools here charge, you could get your gear looked at, its fitment to you examined, shed bad habits, heal training scars and get a good foundation of marksmanship fundamentals that you can build upon.

It would cost way more in time, ammo and frustration to chase this dragon; if you even catch it.

--Fargo007

 

[JoshcBoucher]

Welcome to the "HARD PART" of long range. Wind is tricky. Good luck! On a side note, 2 weeks ago I was doin the same thing at 600, with a borrowed gun. What REALLY added to my frustration, was a niece of mine { shooting her first shots EVER} getting behind the same gun and ,POW DING, POW DING. Made me feel OLD!!!!, and utterly useless.

 

[jvr]

Thanks for the direction. I will re-chrono. Next trip. If I am still getting high readings I will have repaired.

Zero at 50 because 0 to 200 requires no adjustment to speak of. I live in New Orleans. I doubt the shots would be much over that.

1/10 twist. Savage precision carbine. Stockade bedded stock.

Most of my 3 shot groups touch at 100. (If I take my time and a calm day).

I am shooting over the marsh. (Backing to the Gulf of Mexico ) Gusty squals would interrupt the shooting. My wind reading skills are limited. (An area I am working on)

I would love some formal training on the long gun. I have taken several classes on carbine and handgun. There is nothing close that I am aware of.

Thanks again.

 

[djskit]

I'll add my vote - something is not adding up. As others have mentioned, north of 2900 fps with factory 168's from a 20 inch barrel is impossible.

You noted that both initial shots at 400 and 800 were low...so the data is incorrect.

What I did not see mentioned was this...note what you correct elevation is at those distance and reduce the velocity in your program until it agrees with your final adjustment.

Your factory 168's out of the 20" barrel may well be going so slow at 800 that they are tumbling - so you may never get any satisfactory results at 800 with this set up.

I recently coached a clinic where my student was shooting a 22 inch barreled 308 hunting rifle with 150 game kings. We got him solid hits at 800, but the wheels fell off at 900. The hits were all over the place.

 

[walt willis]

Had another thought...

If you could find a friend that can shoot well enough to get a tight group out at long range, you may want to let him shoot first and then use his rifle at the same target.

That way you can determine if it is you or the rifle.

Then let him shoot your rifle too.

 

[timelinex]

24" at 800 yards is 3moa. I highly doubt it's the wind or anything else like that because in 20 rounds you would hit it. Unless the wind was absurdly strong and erratic(doubtful) , it would not continually chase you off at that distance off a 3moa plate.

If I had to guess it's because you were canting the rifle differently every shot. You would try to adjust for your last shot, but on your next shot you canted it differently. This would create the problem you are describing. That along with form and wind can bring you off the plate continually.

If you don't have a bubble level, next time make sure you line up the reticle to some landmark exactly the same way before each shot. You should see much more consistency.


Edit: I just realized your shooting 168s..the other thing it could be is they are tumbling. If they are tumbling, that too would create a similar problem. Regardless, the point is it is not wind or "long range experience/skill".

 

[delfuego]

2900 fps with factory 168's from a 20 inch barrel is impossible.

2600+/- fps is more like it. Your calculations are off.
I ran your numbers in JBM. Using a 50y zero and 10mph wind

168 @ 2923 fps

yard inch drop moa drift moa
400 -27.0 -6.5 12.3 2.9
800 -179.6 -21.4 58.7 7.0

168 @ 2600 fps

400 -36.0 -8.6 14.7 3.5
800 -238.2 -28.4 71.3 8.5

This means with your drops are off by a lot.
9" @ 400 w/2.4" wind
59" @ 800 w/12.6" wind

Even if you got your wind call perfect (which ain't easy) your numbers would be 59" low and 12.6" left or right.

 

[ccoker]

Move up in bullet weight
I shoot a 20" 308 an at 500 yards the 175/178 do much better than 165/168 due to less wind deflection.

MUCH better
I run 178 AMAX at 2575 because they are very accurate, cheap and work great for range or hunting.