07-14-2011, 02:39 PM
Tony,
The other part of the news is so-so, but not particularly discouraging if one takes the M855A1 as an example.
The sectional density of the 100 gr 6.5 is about mid-way between the 62 gr 5.56 and the 147 gr .308. This would suggest, based on the M855A1 example, that paths to getting the barrier defeat capability up to near equivalence with the M80 should be doable.
While "stretching" the M855A1 and enlarging to 6.5 is one path, there are others that may get to similar or equivalent barrier defeat. Some of them may be more in line with the bullet design constraints placed on UK and European military services.
BTW a 110 gr 6.5 bullet has a sectional density that is within about 0.2% of that of the 150 gr .308 bullet. Adding 10% to the bullet weight and keeping the nominal 2750 ft/sec muzzle velocity, however, means increasing powder capacity by a similar amount, weight goes up, etc.
Cheers!
Joe
Joe
The other part of the news is so-so, but not particularly discouraging if one takes the M855A1 as an example.
The sectional density of the 100 gr 6.5 is about mid-way between the 62 gr 5.56 and the 147 gr .308. This would suggest, based on the M855A1 example, that paths to getting the barrier defeat capability up to near equivalence with the M80 should be doable.
While "stretching" the M855A1 and enlarging to 6.5 is one path, there are others that may get to similar or equivalent barrier defeat. Some of them may be more in line with the bullet design constraints placed on UK and European military services.
BTW a 110 gr 6.5 bullet has a sectional density that is within about 0.2% of that of the 150 gr .308 bullet. Adding 10% to the bullet weight and keeping the nominal 2750 ft/sec muzzle velocity, however, means increasing powder capacity by a similar amount, weight goes up, etc.
Cheers!
Joe
Joe