Hi guys, stumbled into here after being gone for a while. The Yuma test went better than expected. THe Lost River Ballistic Technologies bullets were by far the slickest bullets tested. .30 caliber, .338 caliber, .408 and .50 caliber. They were superior across the board. Here is a picture free copy of the test eval that I conducted in Idaho during the Phase II shoot. Note that there is no optical sight tha can support the .408 CheyTac past 2000 yards.
I will be building single shot .408 / .398 guns this fall using Mike Rock barrels and an action that Mike and I are working on.
1. This report is the results of the Phase II shoot conducted at South Creek Flats, Idaho. The shoot was conducted immediately following testing of the gun system; it�s ammunition, and other sniping cartridges at the Yuma Proving Grounds facility in Yuma, Arizona. The intent of the Phase II shoot was to determine the most extreme range at which we could obtain a 1.5 MOA or better group on a target. Additionally, an AN/PVS-14 Monocular and a Monoloc device was obtained to determine best range conditions for shooting at night. Additional data was collected based on changes made to the gun system after the Phase I shoot conducted in May.
2. The test consisted of the following events and procedures:
� Grouping ability at ranges to 3000 yards.
� Fire control systems capability to support the gun platform.
� Gun system ergonomic upgrades and shoots ability features.
� Initial evaluation of selected Night Vision System for use on the military .408 CheyTac package.
3. Pre-Test Preparation: Prior to the Phase II shoot, the gun system was taken to EDM Arms in California to have the proposed upgrades and changes made to the system. The final changes include (customer options selected are italicized):
� Use of long bipod extension and relocating this extension approximately 1� higher and closer to the barrel.
� Use of 88.50 MOA incorporated angle in the scope base.
� Keplinger set trigger to allow more consistent trigger control during the testing and evaluation phase.
� Redesign of the action by machining away extra steel to further reduce the overall weight of the system.
� The round bolt knob was replaced with a Delrin barrel type knob.
� Two steel retention plates on the receiver used for various purposes were replaced with Delrin items to reduce weight.
� Trigger weight was optimized to 10 oz. In the set mode and 2 lbs. release in the un-set mode.
� PSG-1 style pistol grip was installed for the test. This may or may not be the final design used on the production guns. It will be a customer option however.
� A Monoloc device and an AN/PVS-14 GEN III Night Vision Device were obtained and mated to a Nightforce NXS 5.5 � 22X scope for the night time shooting evaluations.
4. GENERAL RANGE CONDITIONS: The test was conducted at South Creek Flats, Idaho. The range is in the foothills of the Lost River Range and has excellent meteorological and environmental variables that provide a good challenge for a long range system and the shooter. The characteristics of the range were as follows:
� The altitude of the site is 5300� above sea level.
� Barometric Pressure ranged from 25.00 In. Hg. To 25.25 In. Hg. (this was in contrast to the 26.15 In. Hg. To 26.85 In. Hg. conditions experienced at the Phase I shoot.) This required an hour by hour recalculation of elevation settings.
� Air Temperature Ranged from 69� to 95� (in contrast to the 40� F to 65� F conditions at the Phase I test) throughout the test.
� Ammunition Temperature was maintained at 70� F and monitored by NECO temperature strips.
� All long range shooting was done during the night to minimize wind interference. A 1500 watt Halogen lamp system was used to illuminate the front and rear of the target
� Wind data was collected and monitored using Kestrel 3000 wind meters at the gun position and at the target.
5. RANGE OPERATIONS DAY 1, 20 June: The rifle was setup with the L&S Mark IV, M-1 16X as the standard optic for all testing. A Nightforce NXS was available for use with the Monoloc and AN/PVS-14 when needed. An initial zero was established to align the optics with the gun system at 100 yards during the daytime. The initial range for testing began at 1000 yards during night hours on the 20th. It was evident that with additional illumination at the target, the 16X Mark IV would be too much. Here are the results of the 3 range lines shot on the 20th of May. Air conditions were: 25.05 In. Hg., 84� F air temperature, ammo temperature at 70 deg. F.
� 1000 Yards group result: 7� with 3 shots. 25.0 MOA Elevation
� 1500 Yards group result: 8� with 3 shots. 45.50 MOA Elevation
� 2000 Yards group result: 15� with 3 shots. 64.75 MOA Elevation
� 2500 Yard Attempt: Grouping attempt was aborted due to the same extreme elevation problems that occurred in the first Idaho shoot.
Range operations on Day 1 were terminated at 2500 yards as a strong night wind began to blow left to right on the range. We also determined that due to the extreme elevation requirements to shoot past 2000 yards, a more radical base angle would be required. It was also determined that the aluminum base would be eliminated from the system as a bow had developed in the base. As the air temperatures cooled from 90 to 60 degrees, the base metal was contracting. Checking the torque specification at 65 in. lbs. at each range line showed that some movement was occurring as we retorqued the ring nuts. This was due to both the base being bowed and the contraction rate of the aluminum as the air cooled.
On Thursday, June 21, we removed a steel base that is on the Windrunner .50 BMG rifle and modified it to fit the Intervention. A new base angle of 110 MOA was cut on the steel base. It was decided to go with the Nightforce NXS scope so that we could continue with the night vision evaluation portion of the testing.
6. RANGE OPERATIONS: DAY 2, 21 June: Testing on Day 2 began with establishing the range at which the extreme base angle corresponded with the bottom elevation setting on the NXS scope. This range is 1500 yards under the range conditions and with the NXS scope having 95 MOA of available elevation travel. This was good news to us as that mean that we should just barely be able to reach 3000 yards using the NXS scope. Our intent on this day was to establish a grouping capability at 2500 and 3000 yards.
We began shooting at 1500 yards to zero the scope for the range conditions. Once the elevation setting was coordinated we moved to 2000 yards. An elevation verification group was fired at this range. We moved to 2500 yards. A three shot sequence was fired with a calculated elevation setting of +92.50 MOA. The three shots went into a 34� group for an MOA value of 1.35 MOA extreme spread. To catch favorable weather conditions we immediately moved to the magic 3000 yard mark. At this range we identified a further weakness in the optical sights. We were forced to wait until early the next morning as a steady 10+ mph wind blew in from 9 to 11 o�clock on the range.
The base on the gun at this point was machined to 110 MOA. Using the Nightforce NXS scope with 95 MOA of available elevation travel, we were maxed out for elevation and had to �hold over� an additional 8 MOA over the aiming point to get on paper. The shots downrange were correct for elevation after two sighting shots. Due to an unexpected sight condition where the erector cell was �bouncing� inside the main tube due to the extreme elevation setting, we could not establish a group. Another factor was optical distortion due to aiming the erector cell to the outer edges of the objective lenses, a.k.a. Optical Vignetting. We did get one strike on target. The bullet hole indicated a straight on impact and no signs of instability at the target. At this point, we were out of projectiles and reloading components. With several identified support system weaknesses we cancelled further attempts at 3000 yards until these weaknesses could be identified and fixed.
� 2500 Yard Group Result: 1.35 MOA Extreme Spread. This group was shot in 2-6 mph winds from 10 to 12 o�clock. No corrections or holdoffs for those wind conditions were used. The effects of precession and Coriolis were compensated with by indexing a 1.25 MOA left correction.
� 3000 Yard Group Result: Test Terminated due to optical sight limitations.
7. FIRE CONTROL SYSTEMS CAPABILITY TO SUPPORT THE GUN PLATFORM. This was in the beginning and continues to be the systems major limitation. There is NO current optical sight on the market that can support the gun from 0 to 3000 yards with an elevation range that won�t crowd the erector cell inside the scope tube. Even with optimized base angles, the Leupold & Stevens Mark IV, M-1 with It�s considerable 150 MOA of elevation doesn�t have the optical quality to see the target with the clarity needed to group at 3000 yards. It has the elevation travel, but not the optical clarity. On the other hand, the Nightforce NXS has the optical clarity and the ability to step up or down the power of the scope. It is limited to 95 MOA of elevation travel because they correctly engineer their scopes so that there is not TOO much elevation travel for a small tube, based on variable power range.
Solution: The project is working with US Optics on a combat grade externally adjusted optical sight. This system will have the capability of providing enough elevation travel for 3000 yard shooting and beyond. Issues of optical distortion due to extreme erector cell positioning inside the main tube are eliminated because there is no erector cell. The scope tube itself is pointed at the target by external adjusting knobs. The first prototype is a 3.5 � 17 X. The current Monoloc device will be adaptable to the ocular lens assembly so that the PVS-14 can be used for night work.
Customers that desire the less expensive Mark IV or Nightforce NXS scopes will have a scope with a base angle of 88 MOA. This will support both the Mark IV and the NXS with enough elevation travel for 2000 yard shooting. Base angles for the US Optics EAS will be determined for best operability features.
The aluminum base was rejected due to problems with system repeatability. A steel base will be used in its place. Steel rings are going to be used with the Mark IV and NXS scopes.
8. GUN SYSTEM ERGONOMIC UPGRADES AND SHOOT ABILITY FEATURES. The system features listed on Page 2 were used to shoot the Idaho II scenario. All of the upgrades proved the make the gun more maneuverable and shootable. The system is an extremely stable prone platform. There remain limitations in the application of the gun for non-standard shooting positions, such as those that a conventional military sniper may use in defensive operations or urban environments. There remain 2 issues yet to be addressed in the final design.
� Potential limitations of the length of pull adjustment when shooting with NVD sights.
� Cheek piece issues. The cheek piece on the system still causes some problems. The cheek piece is too short for a shooter to obtain a consistent cheek weld to the gun stock. Typically during testing, the cheek piece was near the rear of the jawbone on the shooter. After prolonged shooting sessions, this area became quite sore.
� Non-bipod shooting. We have a system with a bipod extension in place. It is now located closer to the barrel, giving much better stability for long range shooting. A modification needs to occur to allow the rifle to be fired from non-bipod shooting positions.
9. INITIAL EVALUATION OF THE AN/PVS-14 w/ MONOLOC NIGHT VISION SYSTEM: No rounds were fired through this system due to priorities on daylight grouping capabilities. The system was mounted to the Nightforce NXS scope. With a power setting as high as 10X we were able to identify human size targets to a range of 1500 yards with only starlight illumination. The lighted reticle capability of the NXS scope was a major plus. It did require that we tune the reticle illumination down to the lowest power setting so that the reticle did not overwhelm the target image. This lowest setting however made the illuminated reticle difficult to use for low light NON-assisted (with the PVS-14) shooting. Due to the informal test of the PVS-14 and MONOLOC, it is hopeful that the system can well support the .408 CheyTac for 1500 yard + low light shooting. Extensive testing will be done with the PVS-14/Monoloc at the next test shoot.
10. SUMMARY: The EDM Arms built, .408 CheyTac continues to be a strong performer. The long range envelope was pushed to 2000 yards, sub-MOA and to 2500 yards sub one-half MOA. The major limitation at this point is the daylight optical sight. For 2000 yard sniping, the Leupold & Stevens Mark IV, M-1 or the Nightforce NXS scopes are the optic of choice. To go beyond 2000 yards, the prototype externally adjustable scope from a project with US Optics provides the greatest opportunity to obtain sub-MOA groups at 3000+ yards.
11. POC this Document: Dean Michaelis, Director, Sniping Operations Executive
Dean Michaelis
Sniping Operations Executive
