So I can send a 150gr projectile down the barrel at almost the same speed as 5.56mm and there is no appreciable increase in barrel heat? I am not a physicist by any means; but in my experience, larger calibers (.308, .30-06) heat the barrel up much faster than .223.
Well the velocity really ain’t close. If both are using the same length barrel, let’s say 20” for instance, the 150gr 7.62 NATO is going about 2600 fps. The 5.56 NATO as designed is going about 3200 fps. The weapons world that is really pretty far apart. Now we are talking about using the 6.8 or 6.5 cartridges, I don’t know their ballistics off the top of my head. But remember any comparison, to be valid, must be out of the same length barrel.
But I don’t think the heating of the barrel needs to be higher. Most heavier caliber weapons even full auto, which I do not recommend for the average rifleman, is slower, hence less heat.
Besides after Vietnam, the M16 needed a heavier barrel to function properly. No other small arm I am aware of has had to do that.
The AR15/M16 family has always had heat problems. Nothing new here.
We hear stories of people heating up M16s until they are knocking out the stuck cases with a cleaning rod, musketeer-style. I am curious what would have happened if they had a larger caliber weapon? Would they have run out of ammo before they reached that point or would the larger weapon have heated up even faster?
Actually we were knocking the cases out musket style. There were multiple reasons. The most famous was the non-spec powder used. The other reasons were out of spec chambers, no chromed chambers, out of time, firing before the bolt was locked etc…. I think there were one or two other reasons too. My memory begins to fade over the years on some of the details.
I don’t believe over heating was a cause of stuck chambers. It certainly wasn’t on the M14. Or any FAL some of my Royal Marine friends used in the Falklands, or Yemen. Their problem was in Yemen, where the FAL jammed because of the sand. The Brits later cut “sand” slots in the bolt. The guys said they would still jam on rare occasion because of sand, but not much if they had the “sand slots”. (see why I prefer the M14 to FAL)
During the period of the change over I managed to hang on to my M14. I had a selector on my rifle too. I did run out of ammo a couple times‘ and normally got more, and once got into a fight with a gunner over a couple of belts of ammo to reload my mags with. It was not in a fire fight at that time either. This is war, **** happens, no matter how many rounds you carry. More important is how you expend the rounds you do have.
I also ran out of ammo, later while carrying a M16 too. Running out is running out. I will agree with your point, more ammo IS ALWAYS better than less. But ammo that works better trumps more ammo.
Back to the heat though. A direct impingement system will ALWAYS have MORE heat build up problems than an indirect impingement system it is directly related to the type of action it is. The bullets through the barrel problem will be exactly the same regardless of action type, the damage comes from the additional heat dumped into the operating system in the gas impingement system. Cleanliness r/t action type can be an issue, but is not a major one, most of the time. Not withstanding what happened to the lost convoy’s small arms at the beginning of the war (Jessica lynch).
We? You got a mouse in your pocket? That changes the equation a bit doesn't it? I was comparing 7.62x51 to 5.56x45 earlier (and using very favorable numbers for 7.62x51). If we are using some other cartridge then what does it's wound profile look like?
No we in my pocket, a couple of Manufacturers, many combat Vets, and other knowledgeable folks. In fact IIRC, the 6.8 was requested from Barrett specifically from the SPECOPS community, for most of the reasons already given.
As I have consistently called for was a larger cartridge. Not a return to the 7.62 NATO. In fact a friend of mine just back from Afghanistan informed me that they had a hard time getting 7.62NATO ammo for their guns. And much of the stuff issued was so old the tracers didn’t work.
They did much of their predeployment training with Wolf ammo. He was with a Guard Scout platoon.
In your opinion, which of those justifies the additional issues I mentioned?[/Quote]
Yup. The 6.8spc had the best profile for killing than any of the other rounds shown by a long shot. Now imagine several years of research to make it even better not counting the 5.56 NATO has had almost 50 years trying to get it right.
And once again, YES. I do believe it out way’s all those issues, at least those that really are issues.
Really? Most of the LE/mil guys I talk to prefer the AR. The main issue they had wasn't effectiveness but difficulty in getting H&K to repair and return weapons in a timely manner (or send parts, etc.).
That may be true, these days. They are not repaired much at the armorer level anymore. Think about that, the complaint isn’t lack of wanting one, it is they can’t get them fixed fast enough.
Per you statement. The 9mm effectiveness isn’t/wasn’t a problem, as I observed. It is getting the weapons repaired is the problem. Think that could be fixed with proper emphasis?
Go figure.
Fred
