05-11-2011, 07:43 AM
Thanks for your comments Gene - a few responses:
The new cartridge would make a significant saving in MG ammo and gun weight by being lighter and less powerful, reducing the burden on the soldier. But if the long-range ballistics cannot equal the M80, I don't believe that it would be accepted as a replacement for it.
Agreed. But the main point remains - that whatever barriers are chosen, the new round should penetrate them as well as M80, for the same reason as given above: if it is perceived to be inferior to the M80, then it probably won't be able to replace it.
Agreed. My spec was a first draft of an outline, a full military spec would need to be more detailed.
OK, although the point remains - whatever rifle is chosen (let's take the SCAR H as that's already been mentioned, although a member of the AR-10 family would do as well - or an HK 417) should be the same in every respect except calibre, to allow direct comparisons to be made.
On reflection these requirements are probably not necessary, since in the great majority of cases (except for plate armour) anything that can match the M80's penetration and wound channel size should easily beat M855.
See answer above...
OK, although that's not something I have any expertise in calculating.
The key word for me is existing gun designs...in other words, not that existing guns would necessarily be adapted on a large scale (although they presumably could happen if it made financial sense), but than an existing design (e.g. AR-10) could be manufactured with suitable changes to use the ammo.
LR1955 Wrote:1. To match the retained energy, vertex height and wind-drift performance of the 7.62mm M80 ball round at 1,000 metres.
This is a clearly stated requirement but I would ask what is so important about equaling the exterior ballistics of M-80? If one can only equal the performance, why a new cartridge?
The new cartridge would make a significant saving in MG ammo and gun weight by being lighter and less powerful, reducing the burden on the soldier. But if the long-range ballistics cannot equal the M80, I don't believe that it would be accepted as a replacement for it.
Quote:2. To equal the barrier penetration performance of the 7.62mm M80 in terms of overall penetration of a range of media while maintaining its trajectory ("blind to barriers")
The barrier or barriers and media need to be specified along with ranges where the same must be penetrated along with residual effects or the entire project will lack focus.
Agreed. But the main point remains - that whatever barriers are chosen, the new round should penetrate them as well as M80, for the same reason as given above: if it is perceived to be inferior to the M80, then it probably won't be able to replace it.
Quote:3. To exhibit rapid and reliable yaw on impact with ballistic gel representing a body, ideally commencing within 50mm of penetration and completing bullet upset within 250mm.
This needs to be stated in terms of range and intermediate barriers.
Agreed. My spec was a first draft of an outline, a full military spec would need to be more detailed.
Quote:4. Compared with the M80, to reduce the weight to 80% (assuming similar materials) and to reduce the recoil energy in a similar rifle to 60%
If this is to be a requirement then a standard rifle must be identified from which someone can determine what 60% means. It is not hard – just state the rifle that will be used.
OK, although the point remains - whatever rifle is chosen (let's take the SCAR H as that's already been mentioned, although a member of the AR-10 family would do as well - or an HK 417) should be the same in every respect except calibre, to allow direct comparisons to be made.
Quote:5. To deliver a substantial improvement at all ranges over the 5.56mm M855 in barrier penetration and trajectory maintenance through barriers.
‘Substantial’ must be clearly defined.
5. To deliver a substantial and reliable improvement in terminal effectiveness as measured in the size of the permanent channel created in ballistic gel tests within the 50-250 mm penetration zone, regardless of the bullet angle of yaw on impact.
Again the terms ‘substantial’ and ‘reliable’ must be clearly defined.
On reflection these requirements are probably not necessary, since in the great majority of cases (except for plate armour) anything that can match the M80's penetration and wound channel size should easily beat M855.
Quote:7. Compared with M855 ammunition, to limit the weight to 160% (assuming similar materials) and to limit the recoil energy in a similar rifle to 200%
What standard rifle will be used and why?
See answer above...
Quote:9. The standard ball bullets should be made of lead-free materials and be suitable for economical mass production.
OK but now, you have to state the cost of the bullet. Must not cost more than X amount of money.
OK, although that's not something I have any expertise in calculating.
Quote:10. The cartridge designs should be optimized for use in conventional military magazine-fed and belt-fed automatic weapons, so that existing gun designs can be adapted to use them.
Again, the key word is ‘adapted’. This needs to specifically defined in terms of parts.
The key word for me is existing gun designs...in other words, not that existing guns would necessarily be adapted on a large scale (although they presumably could happen if it made financial sense), but than an existing design (e.g. AR-10) could be manufactured with suitable changes to use the ammo.