05-17-2011, 05:37 PM
Quote:I gather from your earlier posts that a full-length (7.62X51 NATO COAL) cartridge is acceptable. Further, you ask that the bullet potential for penetration and perforation be at least that of the 7.62X51NATO M80 round. Most importantly, if I correctly interpreted your comments, the lethality need only be intermediate between that of the 5.56 and 7.62 at all ranges.
Gents,
I would also stipulate that the new projectile meet or exceed 7.62 NATO M80 lethality out to 600m, and exceed its penetration of standardized mediums at 500m. I'm not sure how lethality can be measured for developmental testing, since there is no scientific baseline to establish it, but I have some bullet design ideas that are multi-role, i.e.: meant to yaw in tissue, as well as penetrate hard targets.
The design I shared with a company in North Carolina 8 years ago peaked their interest, but I never followed up with it. It basically uses some ideas from the Russian improved 5.45mm projectile named 7N10, with a stacked cone narrow rod of tungsten or hardened steel, with a lead filler, and a uniquely shaped internal tip for the lead with a hollow nose cavity, and a thin full metal jacket with cannelure. This was for a 5.56 project, but the same thing could be applied to any larger caliber of course.
I would like to approach the new cartridge specs from 1) on-target performance, 2) Trajectory requirements, and 3) weight limitation constraint parameters. Then look at projectile dimensions, cartridge geometry, propellants, and links. It seems that much of the projectile theoretical and practical work has us focused on something between 5.56 and 7.62 that would be optimum, and most would agree on that. On one hand, I would really like the trajectory performance of a 7mm WSM, with the recoil and size/weight of a 5.56, but that ain't happening with what we currently have to work with. There has to be a compromise somewhere in the middle.
I think we can all agree that 6mm is the bare minimum in acceptable diameter to get the length/weight we need, and 7mm is probably the maximum to keep weight and recoil down, while finding the best aero-dynamic performance from a mass-produced projectile.
6mm offers the best terms in recoil & weight reduction and aerodynamics simultaneously, and possibly penetration and wound effects if it can yaw in tissue and fly straight through the standardized barrier mediums. It also would be easy to get to velocity, but could introduce over-bore problems for throat/barrel life.
The 6.5 seems to alleviate a lot of the potential drawbacks of 6mm, but poses significant challenges with regards to case capacity getting it to 2800 fps.
Do we all concur on this?
LRRPF52