A BRITISH Army sniper has set a new sharpshooting distance record by killing two Taliban machinegunners in Afghanistan from more than 1 miles away

[riohog 5,696]

OK, hands up if you believe that a highly trained sniper operating at 10,000 ft rather than sea level would rely on his sea level zero. Ric.

 

Hey Ric, out of interest I ran some data through Sierra Infinity 5.

 

Based on a MV of 956 mps & 200 grain .338 bullet.

 

At sea level a zero of 1000 yards would give a -2050.82" drop at 2000 yards, -9321.89" drop at 3000 yards

 

At 10,000 ft above sea level : 2000 yards would give -1245.33" drop and 3000 yards would give a -6255.44" drop.

 

Means not a lot but it's interesting to see the difference altitude makes. In comparison if the guy had kept his "at sea level zero" the bullet drop would have been equivalent to him shooting a target at 1800 yards (2000 yards 10,000 ft above sea level) and 2750 yards (3000 yards 10,000 ft above sea level).

 

If that makes sense.

 

John

dont forget ..uphill and downhill variants in zero!!a lot of variants in a long shot !!

[RicW 67]

John - Interesting indeed. Are there any figures available concerning the effect on MV of reduced atmospheric pressure? Surely, if the charge is producing the same chamber pressure, which I think must be the case, and the "outside" pressure is lower, the result must be greater velocity for the projectile?

 

Whatever, if some guy points a .338 Lapua at me I SURRENDER!

 

Ric

[HUnter_zero 58]

dont forget ..uphill and downhill variants in zero!!a lot of variants in a long shot !!

 

Tell me about it. I have one area of land where I can shoot across two valleys, total range is just over 1000 yards, even my range finder will not read back. I put a load of balloons out and retired to the other side. Hitting the balloons wasn't what I would call easy. The wind buffeting made for some very ad-hock adjustments. Thermals were another problem. Good fun but if deer learn to shoot back, I'd up grade to a rock launcher if I had to shoot'um at 1000 yards

 

John

[HUnter_zero 58]

John - Interesting indeed. Are there any figures available concerning the effect on MV of reduced atmospheric pressure? Surely, if the charge is producing the same chamber pressure, which I think must be the case, and the "outside" pressure is lower, the result must be greater velocity for the projectile?

 

Whatever, if some guy points a .338 Lapua at me I SURRENDER!

 

Ric

 

 

I could run standard load data through Quick Load, which would give a mathematical model of internal chamber pressures (albeit a very accurate one) and see if there is a way to tweak environmental effects and compare both.

I'll sort it later for you because this PC is running Windows 7 and my copy of Quick load will not run on this PC, so I'll have to boot up a laptop which I keep for reloading and connecting to my chronograph.

 

John

[kevin from bristol 95]

i can't see were it say 10,000 ft in the report ?

Edited May 5, 2010 by kevin from bristol

[riohog 5,696]

dont forget ..uphill and downhill variants in zero!!a lot of variants in a long shot !!

 

Tell me about it. I have one area of land where I can shoot across two valleys, total range is just over 1000 yards, even my range finder will not read back. I put a load of balloons out and retired to the other side. Hitting the balloons wasn't what I would call easy. The wind buffeting made for some very ad-hock adjustments. Thermals were another problem. Good fun but if deer learn to shoot back, I'd up grade to a rock launcher if I had to shoot'um at 1000 yards

 

John

yes i understand fully the problems there ..what i really meant is shooting at a target at lesser /greater angles above or below 10degrees up /down will have a dramatic affect on the origenal zero //gravity thing !!along with alltitude ,barametic preasure ,wind speed ,outside temp..complecated affair for the spotter !! to relate all this info to the marksman,made easier these days by the technoligy in his rangefinder clever stuff

[RicW 67]

i can't see were it say 10,000 ft in the report ?

Agfhanistan is w-a-a-y up in the Himalayas.

 

ric

[activeviii 8]

http://www.thisisgloucestershire.co.uk/cheltenham/Cheltenham-sharpshooting-sniper-breaks-record/article-2104317-detail/article.html

 

 

from the local rag.

 

Phil

[JonathanL 4]

John - Interesting indeed. Are there any figures available concerning the effect on MV of reduced atmospheric pressure? Surely, if the charge is producing the same chamber pressure, which I think must be the case, and the "outside" pressure is lower, the result must be greater velocity for the projectile?

 

Whatever, if some guy points a .338 Lapua at me I SURRENDER!

 

Ric

 

It would also mean that it's velocity would reduce less rapidly so it would travel further before it hit its trans-sonic phase which is a major potential cause of innaccuracy.

 

Looking at the figures again; the military ammo actually uses a 250grn bullet which will make a big difference. At Sea level at 59 degree air temp it will fall below the speed of sound at around 1750 yards.

 

At 10,000ft at 40 degrees you get another 900 yards on that!!! So, chances are that those bullets were still supersonic when they found their targets. Based on a 500 yard initial zero (at either altitude) you get 1,700 inches less drop at the higher elevation. Now, if you have a Sea-level 500 yard zero, for instance, I'm assuming that at 10,00ft you'd get significantly less than that 1,700" drop.

 

I've just run those figures 3 times as I didn't quite believe that I'd read them right. They are though.

 

I'd like to know what ammo is actually being used out there in these rifles. I wonder if they are using whatever is standard military issue or whether they are using something else to take into account of the extreme distances they are engaging targets at? Probably not though as I don't think a significantly longer bullet will fit the magazine.

 

Interesting stuff though.

 

J.

[HUnter_zero 58]

 

I'd like to know what ammo is actually being used out there in these rifles.

J.

 

 

From what I could find the MV is 958 meters per second, the source I found was 200 grain bullet (?).

 

Quick load has not ability to alter environmental factors. If we could find out exact MV & bullet weight I could run it through Quick load and come up with a replicated round (powder weight etc.). From there if we knew what range the military snipers zero then I could run the data with multiple BC's to give a very accurate trajectory graph and data.

 

John

Edited May 5, 2010 by HUnter_zero

[JonathanL 4]

 

I'd like to know what ammo is actually being used out there in these rifles.

J.

 

 

From what I could find the MV is 958 meters per second, the source I found was 200 grain bullet (?).

 

Quick load has not ability to alter environmental factors. If we could find out exact MV & bullet weight I could run it through Quick load and come up with a replicated round (powder weight etc.). From there if we knew what range the military snipers zero then I could run the data with multiple BC's to give a very accurate trajectory graph and data.

 

John

 

.338 Wikipedia

 

This says the standard military load is a 250grn bullet at about 3,000fps which sounds right from everything I've read. I'm just wondering if they were using anything other than whatever the standad military load is given the long distances they tend to be shooting at in Afghanistan. They may be but, then again, maybe not given that I'm sure that I read that the 250grn bullet was about the longest the mag could handle.

 

Some of the high-BC ultra-low-drag bullets must be staying supersonic at insane distances at that sort of altitude.

 

J.

[RicW 67]

Thanks for the info. My guess is that they would be using match spec ammo and do some very careful work zeroing to the optimum for the altitude. Given the increased range, it might well make sense to zero a sniper rifle for 1000 yds, or even 1500 yds, at those altitudes.

 

Ric

 

Edited to add Blackfox, that photo of the rifle? That's the AI stock I want for my .204.

Edited May 8, 2010 by RicW

[SNAP SHOT 194]

to put those round down range at that distance if the wind changed even by 2mph the bullets would be waaayyyy off...

 

now anyone whos been at 10'000 feet knows theres always a wind blowing... allbeit an ever so slight one at times, no mention of altitude has been mentiond as far as i can see...

 

hats off to the guy.... the boys got skill but some luck too....

 

http://kitup.military.com/2010/05/brit-makes-record-sniper-kill-in-afghanistan.html

 

 

 

 

 

 

[riohog 5,696]

50% of afganistan is above 2000 mtrs of sea level rising to 7000 mtrs in the hindu kush ,

 

chances are the the shot ..was taken at alltitude somewhere between those !!

[blackfox 9]

Thanks for the info. My guess is that they would be using match spec ammo and do some very careful work zeroing to the optimum for the altitude. Given the increased range, it might well make sense to zero a sniper rifle for 1000 yds, or even 1500 yds, at those altitudes.

 

RicLFG

 

Edited to add Blackfox, that photo of the rifle? That's the AI stock I want for my .204.

 

 

Ric me old fruitcake, yep the AICS stock is sexy im going to get one. My new toy is going to be a .308, im thinking of starting with a SPS Tactial with 20" Heavy barrel or go with another SPS Varmint with a 26" heavy barrel........

 

Anyways went to a mates house today, he has some nice toys, custom .17 rem, (soon to be)custom .17hmr and a very sexy custom .22-250 Ackley - thats based on a rem 700 action, custom barrel in a AICS stock, tis very nice....

Edited May 8, 2010 by blackfox