Originally Posted by Stephen_H
IMO It's more important to look at doctrine than chase a magic bullet. At 300m and beyond US Soldiers and Marines are going to likely do one of two things; use their support weapons to pin the enemy down and close on their positions or they are going to use their support weapons to pin the enemy down and call in CAS. Head/COM shots at 300m and beyond with a 1X Aimpoint or even a 4X ACOG on a moving target are difficult if not impossible except by the most highly trained individuals. I say arm the SDMs with an M110 and have at it.
Absolutely agree! Here is a little background for my research. In Afghanistan we are getting engaged beyond the distance we train to in our marksmanship programs. Traditionally, we would fix the enemy with fire and manuever on him. Afghanistan presents several problems in that regard. First, we have too much crap to carry. Solders now have about 60lbs of gear on them, operating at elevations of 8000 feet and are slow to manuever, especially against an enemy who ussually occupies the high ground. The trend now is to fix with direct fire and call in either CAS, CCA (Apache's) or indirect fire (Normally 120mm mortars) to finish the enemy. These assets are not always available and are becoming more politically restricted, unfortunately
So, now we know we need to engage targets beyond 300m. Our training and doctrine don't address it and our equipment is marginally capable at that distance.
6.8 and 6.5 certainly increase lethality from 0-300m. The edge appears to go to 6.8 in the short range. However, as range increases, the edge goes to 6.5. It's better BC. means less wind drift and drop compared to 6.8, which minimizes shooter error. Its penetration capability is also better, all things equal, due to higher sectional density. Thus, my question as to the lethality at short range. If the 6.8 is substantially better I would lean more toward that round, as engagement distances in most theatres will be within 300m. If it is not, then 6.5 seems to be a more capable overall cartridge for all types of terrain.
I'm also interested in the lethality mechanism of the rounds. Since studying the 5.56 we have become fascinated with fragmentation though few military rounds of larger calibers fragment. Ideally they yaw early and create a larger permanant cavity. It seems that a longer bullet would create a larger permanent cavity when it yaws, assuming design and construction were the same.
Also, the SDM program is a joke right now. FM 3-22.9 has a total of 12 pages dedicated to the SDM. The focus is on training, which is good, but the weapons range from modified M14's and M16A2's to M4's. Optics are not standardized either. I agree, M110's for the SDM's would be great, if they fix some of the QC issues. Some balk at the cost of the system, but for the cost of one F-22 fighter we could put two M110's in each infantry squad and have a capability we have not had since the reorganization of the infantry squad in 1960 and the loss of the M1D.