14 Dec 16
Heat build-up is inherent to all auto-loading military rifles with large-capacity, detachable magazines.
And heat, when sufficiently intense, will eventfully cause the rifle to break-down and become unusable.
For most non-military owners of these rifles, the foregoing is a moot point, as when used under “normal” circumstances, even most “acute” circumstances, these rifles will never get hot enough to approach the aforementioned braking-point.
The AR, for example, is designed so that, under extreme heat, the gas-tube will fail first, preventing the barrel from getting so hot that it softens and actually “droops,” eventually causing bullets to blow out the side. Simply replacing the gas-tube will subsequently return the rifle to full service.
However, for the forgoing to occur, one would have to fire between twenty and thirty magazines (thirty-round) on full-auto, in rapid succession. Conversely, when fired exclusively in semi-auto mode, most military rifles will never get hot enough to fail!
During our Urban Rifle Courses, I require an exercise where students fire three magazines (thirty-round) in rapid succession, in semi-auto mode. Each shot is aimed, but most students are able to thus fire at a sustained rate of three rounds per second. Even during this relatively mild drill, rifles get hot enough so that oil and other lubricants burn-off, causing the rifle to “smoke.” Forends, particularly aluminum ones, sometimes get too hot to hold! Students need to understand that all this is perfectly normal, and that their rifle is designed to continue to run under these circumstances.
But tight, temperamental “competition” rifles (masquerading as real rifles) predictably choke during this drill. Such rifles are designed and built to impress your friends, not your enemies, and are thus not recommended for any serious purpose. We encourage students not to bring these “non-serious” guns to our Courses.
In my opinion, a full-auto capability is the last thing you want on your rifle!
Precious few are the personal defense circumstances under which full-auto fire is genuinely useful. Even then, it takes a skilled Operator, and a vast reserve of ammunition, to put full-auto fire to legitimate use. And as noted above, full-auto fire from an auto-loading rifle is only sustainable for a relatively short time in any event.
In the hands of the unskilled, full-auto fire goes mostly over the heads of the enemy, while quickly drawing-down a limited personal supply of ammunition. I can’t tell you how many times I’ve seen it!
Not much to recommend it!
So, sustained, full-auto fire cannot be reliably delivered via any auto-loading rifle. Such “suppressive fire” requires a legitimate, crew-served, belt-fed machinegun, with multiple spare barrels that can be quickly exchanged when they overheat.
This is a military requirement and not relevant to most personal-defensive situations, and thus not relevant to personal defense training, at least not yet!
And, if you’re wondering if there is a point lurking is all this, here it is:
Stop worrying about “full-auto” fire and start learning how to run your trigger correctly, so that you can deliver deadly, individually aimed shots in rapid succession at multiple threats, at all ranges that can be reasonably expected.
… in a cold, muddy ditch, at night, in the rain!
Good riflemen are priceless! “Cowboys” are highly expendable!
We’re only human, and thus susceptible to all ills to which flesh is heir!
So, shunning the “glamorous” and “melodramatic,” we need to quietly discipline ourselves.
“The first thing you need is the last thing you want”
A challenge for all of us!