Hello, I've been reading here but haven't posted I don't think. If I have it's been quite a while. Very informed and smart discussion here. SOE does and trains extreme range shooting, mostly for the military guys, and we also run training events for civilians that want to shoot to 2000 yards or more in field conditions. Here is an AAR that I was asked to post here. If i'm out of bounds with this info, I apologize. Comments are invited. Here you are.
AFTER ACTION REPORT: LONG RANGE CLINIC 6-9 JULY 2006
6 July – Overview. The training was attended to 2 shooters. At the last minute, several shooters cancelled due to other commitments. The date of this shoot was released late and didn’t live much time for shooters to arrange for time off etc.
Gun Systems Present: The intent was to include a 338 Lapua rifle in this shoot to compete against the other three cartridges represented. The planned rifle, an Accuracy International 338 LM was not through customs as one of the attending shooters had planned to bring it to the shoot. We will have one for the 22-25 July shoot.
1. .50 BMG – Barrett M107 System with an 8 x 32 x 56mm Nightforce scope on Barrett adjustable rings.
2. .408 CheyTac – M200 full military version rifle with a 5.5 x 22 x 56mm Nightforce scope on Nightforce rings.
3. SOE built 375/408 long range prototype rifle.
4. .408 CheyTac – M310 Civilian Package rifle.
6 July was a planned classroom day. Much of what SOE trains in its programs are not covered by any other sniping or long range shooting program within the US military or other civilian school. The nature of the listed classroom subjects bears witness to this fact.
Much of the classroom instruction takes on the nature of a discussion. There are always many questions and discussion on the answers to those questions. The classroom training went into the early evening. Desktop training on the CheyTac Advanced Ballistic Computer (ABC) was included as SOE believes this to be the best and most advanced computer fire support device for long range shooting on the market today. All of the long range shots were done with the use of the ABC to generate the Elevation and Windage settings for the rifles.
Care and Maintenance of Big Bore Rifles
Special Marksmanship Practices of Extreme Range Shooting
Determining the Effects and Correcting for Meteorological and Environmental Effects
Ammunition Management for Long Range Shooting
Ammunition Selection from Issued Cartridges – DELETED DUE TO TIME CONSTRAINTS
Construction of High Precision Cartridges for Long Range Shooting – DELETED DUE TO TIME CONSTRAINTS
The Theory of “Error Budget Long Range Shooting” – DELETED DUE TO TIME CONSTRAINTS
Internal Ballistics Factors of Long Range Shooting
Introduction to the Ballistic Data Tables and Gun Integration
Collecting Critical Gun Data for Data Table Integration
The rifle zeros were done at 525 yards. It is not critical to have a fixed “even” known distance when zeroing with the CheyTac ABC, but you do have to know the range to the target. We frequently use uneven range values (525 yards) to do the zeroing so that the shooter is in the best ground position available. When you zero the CheyTac ABC to the rifle, you simply enter the range to the target in yards or meters, enter the air temperature, air pressure, ammunition temperature (to adjust for muzzle velocity values), the guns muzzle velocity and then adjust the elevation knob on the scope to match the elevation setting generated by the computer for that shot. Then the ABC and the gun are in “tune” as is the shooter’s particular individual zero. (More info on this method on the upcoming SOE / CheyTac ABC page on SOE’s website.
All guns were chronographed on the South Creek range before zeroing. Muzzle velocities obtained were:
Barrett M107 .50 cal – HSM AMAX ammo – 2660 fps
M310 .408 – 419 gr. HB – 2860 fps
M200 Military Package 408 CheyTac – 419 gr. HB – 2860 fps
375/408 SOE – 350 gr. LRBT M40 Match – 3265 fps
Zero Guns at 500 Yards – All rifles shot 1 MOA groups with ease. M107 with AMAX was at 1.4 MOA.
Long Range Grouping Exercises 525, 1125, 1525 Yards – The 408 and the 375/408 were the easy winners in this shoot. These guns are designed for superior stability and shoot ability. The M107 is challenged directly by those two shooting standards. The M107 however did respectably well shooting 1.5 MOA at these ranges. SOE’s director shot the rifle during these drills. SOE has extensive experience going back to 1993 training Special Forces snipers on the shooting and marksmanship demands of the Barrett rifles. SOE trained Barrett shooters are guaranteed to be 1.5 MOA and better shooters when using quality match ammunition. The day was ended at 1525 yards due to time constraints.
The CheyTac ABC was used to control the fire of these guns. We went from 525 to 1125 to 1525 yards using the ABC to generate the elevation and Windage settings at these ranges. We did not walk rounds in to the target, which is expensive on ammo costing $4.00 a shot. The ABC generated dead accurate elevation settings that would have resulted in X and 10 ring shots for elevation at all three ranges.
South Creek Range – 2025 yards. In the morning, we started with cold gun shots at 2025 yards at the South Creek range. The M107’s supersonic range was questionable at this distance so we did not group the M107 at this range. We also wanted to proceed directly to the mountain range to shoot unknown distance. The 408 CheyTac M200 gun and the 375/408 SOE gun both shot 1 – 1.5 MOA at the 2025 yard mark. The 375 however, had a significant advantage as these ranges. Data below:
375/408 – Elevation setting for 2025 yards – 43.75 MOA from 100 yard zero. Velocity @ 2025 = 1822 fps – 2.50 seconds flight time.
408 CheyTac - Elevation setting for 2025 yards – 64.50 MOA from 100 yard zero. Velocity @ 2025 = 1404 fps – 3.06 seconds flight time.
(For comparison) M107 / AMAX @ 2660 fps – Elevation setting for 2025 yards – 75.25 MOA from 100 yard zero. Velocity @ 2025 = 1309 fps – 3.30 seconds flight time.
8 July - From South Creek, we moved to our steel target long range located near King Mountain, in central Idaho. Elevation is about 7500’ ASL. Air pressure was 23.65 In. Hg. With an air temperature of about 92 deg. F. This range consists of 15 steel targets at ranges from 1000 yards to 2245 yards. The targets vary from 20” x 40” to small targets of 14” x 14”. The big targets are not the more far in range, and the small targets are not the closest ones. The shooting positions here are challenging as they are in field condition.
Shots at targets in the 1500 yard plus ranges require that the guns be elevated to the long extent on their bipod legs or rucksacks. This creates inherent instability that shows each gun's weakness in design and execution. The bipod above the barrel design is superior in this environment. Guns like the M107 with its unstable below the gun design have severe limitations in this environment. The result is usually a lot of vertical stringing of the shots and unpredictable results.
All three represented cartridges have high BC values. (AMAX - .952) (408 CheyTac - .945) (375/408 SOE – 1.018). These high performance rounds all had the ability to attack targets at all but the 2245 ranges. At this range, only the 408 and the 375/408 were able to compete. The gun design limitation on the M107 had a drastic effect on the gun’s ability to be accurate for 1st or 2nd shot engagements on targets. A 12” steel target was attacked successfully at 1475 yards with multiple shots using the M107/AMAX combination. (Multiple shots at 1475 were placed at about 1.5 MOA and less). It should be noted however, that military ammunition including the Mark 211, MOD-0 Raufoss round could not be expected to do as well.
9 July – King Mountain location. We returned to the field shoot range. We had planned on shooting another gun position, but decided to remain with the current spot to improve on non-standard gun positions, unstable positions and the demanding terrain at GP2.
The field shoot range is most demanding on the elevation and Windage settings. The terrain here is extreme and as depicted in the photos, resembles terrain in Afghanistan and eastern Iraq in the mountainous border region of Iraq/Iran and North Korea for that matter. SOE does not doe “chasing shots”. Meaning we do not guess at the range and then use historical “data books” to generate an elevation and Windage setting for the gun and shots. Personally, I have not kept a historical shot record for several years. SOE trains that historical records mean very little when you are not shooting in a meteorological environment that you have never been in. All the data books kept in the US will do a professional sniper any good when they go to the Middle East or the Korean peninsula.
In a wrap, the position at King Mountain range demands the following:
1. Gun systems that are supersonic to 2400 yards at these conditions.
2. Computerized fire support to generate accurate elevation and Windage settings for 1st and/or 2nd shot engagements.
3. Super accurate and high BC bullets and ammunition to give you the ability to shoot these ranges.
SOE is doing this shoot again from 22-25 July. The 338 Lapua will be included in that shoot using 250 gr. Scenar bullets, 250 and 270 gr. LRBT J40 match bullets and 300 gr. Sierra Matchkings as well.
Short analysis: The 375/408 and 408 CheyTac are both vastly superior to the M107 rifle and the AMAX projectile. Unfortunately the military is not using the AMAX load except in a couple of small circles. The AMAX is a very capable bullet, but needs more velocity than can be generated by the M107 or other bolt action 29” barrel .50 cal. Rifles to be effective. Supersonic range and flight time are the key figures and the 408 and 375/408 are superior in those values. The 338 Lapua is a key player also, if using the 270 gr. LRBT projectile at 2800 fps or more speeds.
The 375/408 is the current supersonic range king at a supersonic range of 2930 yards at sea level conditions and a velocity of 3265 fps.
Testing and analysis will continue throughout July and into August on these cartridges.
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