05-11-2011, 07:33 PM
JASmith Wrote:The balance of minimum acceptable versus desired performance normally handled in requirements documents by specifying a threshold and an objective performance level. Failure to attain the threshold level means that the candidate is automatically rejected. The objective level is what the requirements team would really like to see within reasonable technical limits.I'm glad you brought that up, Joe. I was going to do it, but darned if I could remember the "threshold" term.
Quote:Second, I'm sure that we are tacitly assuming the same barrel lengths in our discussion. We need to specify that so that someone doesn't try to compare the performance of the 7.62 in a 20" barrel with that of the new cartridge in a 14.5" barrel.Who would do such a thing?
Actually, I think it's inevitable, because 20" is the standard barrel length for the UK's L85 rifle, but 14.5" is standard for the US Army's M4 carbine.IIRC, I got into a discussion on the old forum about this. Comparing the same barrel lengths places an artificial limitation on the matter, whereas in the real world, different barrel lengths are used.
For instance, why would one compare 7.62x39 and 5.56x45 in same length barrels, when on the battlefield they use different lengths?
The US Army seems set on the idea that weapon overall length not exceed that of the M4, so much so that the XM8 was fitted with a 12.5" tube! :p
Except in the case of the Mk48 machine gun, is there any reason to think the new cartridge would be used in the same (20-24") barrel lengths as standard-issue 7.62mm weapons? Perhaps the Brits would develop another 20" barrel bullpup in the new caliber, but is there any reason to think that the US Army would abandon the carbine and its circa 14" barrel?