Tony Williams Wrote:I see your point, but I completely disagree with it. The performance of cartridges needs to be compared on a like-for-like basis - i.e. using the same barrel lengths - because that demonstrates what they are capable of.Unfortunately, that does not necessarily show what they are capable of with the barrel length(s) actually used on the battlefield.
For instance, to compare performance of 7.62x51 and 7.62x54R using the same barrel lengths would give a false comparison of ballistics as actually used in the L129A1 (16" bbl) and SVD (24" bbl) rifles in Afghanistan.
Quote:We have been discussing long-range performance here, in which 5.56mm weapons are frankly irrelevant - the comparison is between the Grendel and 7.62mm. And the barrel length of the M240 MG (i.e. probably 95+% of the 7.62mm MGs in US service) is - guess what? 24.5 inches!I agree the discussion is about 6.5G vs 7.62mm. However, 6.5G was designed to fit 5.56mm weapons. As such, it would be used in something like the Mk46, not the M240, so barrel length of the latter is completely irrelevant.
If you object to citing the (16") barrel lengths of recent 5.56mm weapons like the Mk46 LMG and M27 IAR, look at those in 7.62mm: Mk17 Std, 16"; HK417 Std, 16"; L129A1, 16".
Plus, the German MG5A2 Infantry machine gun has an 18" barrel, the M60E6 adopted by Denmark has a 17" barrel, and the Polish UKM-2013 has a 17" barrel option.
Face it, the trend is to barrels significantly shorter than 20" length, so it would seem prudent to plan accordingly.