Military vs Homegrown

 Took the No4Mk1/2 7.62x51mm NATO conversion to the range this morning to run a 200 yard test between the M852 Match and my handloads of 41.7grns of IMR4064.  I only had two targets available to use with one of those being an official SR1. I had enough time to set up the chronograph @ 78ft from the muzzle to reproduce military measured velocities. I only had 45 minutes to work with at that time with no sight in shots. The first test was with my handloads. The very first cold bore shot was high and to the right. After the second shot every following shot settled down enough to get a good fifteen shot grouping in. The averaged velocity came to 2512 fps.

This range time really played heII with me today. Because of this covid crapola, our reserved times are now in 1 hour blocks unless you have paid for additional time.  I was not as focused as I should have been and I rushed myself.

Here’s a page out of the Army Ammunition Data Sheets, Technical Manual 43-0001-27,  April 1994.  May be of interest.  

User Dissatisfaction with the M118 Cartridge

For several years after its introduction, the M118 cartridge performed satisfactorily, and was well received, although complaints were registered regarding excessive barrel fouling associated with ammunition lots having WC846 ball propellant. A series of tests conducted at Frankford Arsenal concluded that, although the WC846 did foul the bore somewhat, the fouling was no worse than when IMR 4895 was used, and the effect of the fouling on accuracy was too small to be observed. However, they noted that WC846 residue was much harder to remove from the bore than IMR 4895 residue.

Another user complaint regarding propellant was the higher bulk density of WC846 (0.980 g/cm versus 0.900 g/cm for IMR 4895). WC846 generally meets the required velocity/pressure levels at a charge weight that allows a small air space inside the cartridge. Whereas, IMR 4895, having a lower bulk density, will normally be loaded to 100% case capacity. Residual air space within the case has always been regarded as undesirable, due to its contribution to variations in velocity and pressure, causing an accuracy variation. As a result of these problems associated with WC846 propellant, all M118 Match cartridge production since 1970 has been loaded with IMR 4895 propellant.

By the early 1970's, the accuracy performance of the M118 cartridge was being severely criticized as inferior, when compared to hand loaded cartridges using commercial Match grade bullets. In fact, several Marksmanship Training Units had initiated a procedure whereby they extracted the bullet from the M118 cartridge and replaced it with a 168 grain Sierra, cal. .30, International Match bullet, and referred to it as the "Mexican Match" cartridge. The ammunition loaded in this manner reportedly achieved an accuracy which was 25% to 50% better than standard M118 cartridges.

Several early attempts were made by Frankford Arsenal, circa 1972-1975, to initiate Product Improvements to the M118 by investigating the adequacy of commercial match bullets, by tightening the M118 Cartridge tolerances, and modernizing production equipment. However, these efforts never evolved into actual approved programs. Finally in 1976, ARRCOM instructed ARRADCOM to implement a "product-definition" to the Technical Data Package (TDP) of the M118 Match cartridge. This effort was to improve the M118 accuracy and made the following changes to the technical requirements:

Velocity
The average velocity, at 78 ft from the muzzle, of the sample cartridges conditioned at 70°F ± 2°F shall be 2550 ± 20 fps. The standard deviation of the velocities shall not exceed 18 fps.

Accuracy
The mean radius of any target of the sample cartridges shall not exceed 2.5 inches at a target distance of 600 yards.

Air Space
The cartridges shall be loaded such that the average and standard deviations of the velocities of various samples of cartridges, each sample handled when fired so as to vary the propellant position from sample to sample, shall not be statistically different.

Bullet Weight
The bullet weight within any lot shall be limited to a tolerance of 0.8 grains.

In addition to the above changes to the M118 specifications, several tolerance changes were incorporated into the drawings of the bullet and cartridge case to reduce concentricity and wall thickness variations. The Lake City Army Ammunition Plant (LCAAP) agreed to produce the M118 cartridge to the revised TDP on a "best effort" basis, since they could not guarantee that compliance with the above mentioned changes would produce a more accurate cartridge. The M118 Match cartridge was produced to those specifications starting in February 1977, the first lot being LC-60.

On 17 August 1978, a briefing was conducted at ARRCOM for Undersecretary of the Army, Dr. Walter LaBerge, to review the status of the M118 Match cartridge. By comparing the past performance against the latest production efforts, it was apparent that the changes made to the TDP had not achieved the desired effect. The ten year production average prior to the change in the TDP was a 2.47-inch mean radius. After producing 12 lots to the revised TDP, this average remained essentially unchanged at 2.41 inches, see below:

LC-60-1 600 yd mean radius - 3.0
LC-60-2 600 yd mean radius - 2.6
LC-60-3 600 yd mean radius - 2.3
LC-60-4 600 yd mean radius - 2.4
LC-60-5 600 yd mean radius - 2.5
LC-60-6 600 yd mean radius - 2.6
LC-60-7 600 yd mean radius - 2.4
LC-60-8 600 yd mean radius - 2.2
LC-60-9 600 yd mean radius - 2.4
LC-60-10 600 yd mean radius - 2.3
LC-60-11 600 yd mean radius - 2.1
LC-60-12 600 yd mean radius - 2.1

12 lot average mean radius - 2.41

It appeared then that a 2.4 to 2.5 inch mean radius represented a practicable limit for the average lot of M118 Cartridge when manufactured by the process employed at LCAAP. Two apparent alternatives remained to improve the M118 cartridge accuracy; completely modernize the production equipment at an initial investment cost of approximately one million dollars or, investigate the practicality of purchasing commercial "Match Grade" bullets and providing them to the load plant as Government Furnished Materiel (GFM). The decision reached at the 17 August 1978 meeting was to pursue the latter alternative. The final action taken at this meeting was to draft a tentative requirements document, which Headquarters, U.S. Army Forces Command (FORSCOM) formalized in a letter to ARRCOM on 14 December 1978. On 22 January 1979, ARRCOM responded to this requirement by requesting that ARRADCOM prepare a Product Improvement Program (PIP), to be initiated in FY81. This was later changed to an Engineering Study Program (ESP) approved in September, and initiated in December, 1979. The activities detailed in the following sections are the result of that program

One hundred bullets of each type were randomly selected and weighed on a Metzler PC 180 electronic scale. Additionally, twenty bullets of each type were measured on a comparator uniformity of outside diameter, overall length, and boattail length. The results of this survey are summarized below:

Bullet weight inspection (all weight in grains)
Bullet Type//Avg Wt//Ext Spread//High Wt//Low Wt
Sierra//168.0//0.60//168.3//167.7
Hornady//167.7//0. 60//168.1//167.5
Nosler//168.0//0.80//168.5//167.7
Lapua//169.8//0.78//170.3//169.5

Bullet dimensional check (all dimensions in inches)
Bullet Type//Overall Length//Diameter//Length of Boattail
Sierra//1.242 max-1.234 min//0.3084 max-0.3081 min//0.170 max-0.160 min
Hornady//1.239 -1.230//0.3086 -0.2080//0.200-0.190
Nosier//1.211-1.200//0.3084-0.3079//0.110-0.100
Lapua//1.255 -1.250//0.3092-0.3086//0.250-0.236

Downrange Velocity Decay
The four commercial bullets and the standard M118 cartridge were tested for velocity retention and coefficient of drag using a Hawk doppler radar to track the projectiles. As would be expected, the M118 bullet being slightly heavier, retains its velocity slightly longer than the others. The Sierra, Hornady, and Lapua bullets track very closely together. The Nosler bullet loses velocity rapidly, which accounts for the poor long range accuracy experienced with this bullet.

Accuracy Mismatch
A series of tests were conducted with each bullet to determine if there was any noticeable trajectory mismatch or other functional problems associated with the commercial bullets relating to the M14 rifle and sight system. No problems were encountered with any of the candidate bullets. As might be expected, when changing from the M118 to any of the other lighter bullets, a minimal sight correction is required.

Aerodynamic Analysis of Match Projectiles
A limited aerodynamic analysis was undertaken to predict why the commercial match bullets are more accurate than the conventional M118 bullet. This analysis consisted of determining the sensitivity of various bullet dimensions on accuracy. The conclusion of this analysis was that the effect of the studied external geometry variations on dispersion is much less than acceptable lot variations, and these variations act only in the vertical plan. Other sources of dispersion that act in both horizontal and vertical planes are: the offset of the center of mass of the projectile from the center of form, rifle barrel vibrations, non-symmetrical reverse flow over the projectile at muzzle exit, core imperfections and improper seating, and yawing during the first few feet after exit. Any difference in dispersion between the standard M118 bullet and the commercial Match bullets tested can only be attributed to the manufacturing processes that allow better control of both internal and external dimensional variations.

Comparison of Bullet Costs
Cost estimates for the two most accurate bullets, the Sierra and Lapua, were obtained from the bullet suppliers, and compared with the latest available M118 bullet manufacturing cost. Costs of the two commercial bullets are predicated on quantities of 5 million or more delivered freight pre-paid to the Lake City AAP. Unit costs for smaller quantities would obviously be higher. It should be pointed out that the cost of the Lapua bullet, because it is imported from Finland, will vary due to fluctuations in currency exchange rates.

M118 - (actual 1980 cost = 6.7c) Projected 1981 Cost (c) - 7.4
Sierra - Projected 1981 Cost (c) - 7.1
Lapua - Projected 1981 Cost (c) - 8.6

Yes, I’ve read all that info that is available on line.  Much of it is extracts from Hettel’s Report.  

ive a couple 30 cans of radway green 762 that i cant bring myself to shoot yet - i still have a lot of lake city im shooting first , unlike you folks im not reloading for my M14type yet 

A square 10 wrote: ive a couple 30 cans of radway green 762 that i cant bring myself to shoot yet - i still have a lot of lake city im shooting first , unlike you folks im not reloading for my M14type yet