mjt@super.org (Michael J. Tighe) (06/21/89)
From: Michael J. Tighe <mjt@super.org> >From: willner%cfa183@harvard.harvard.edu (Steve Willner) >When the M-16 was first put into use, wasn't one of its characteristics >an abnormally small amount of rifling twist? The idea was to make the round >nearly unstable, so it would tumble when it hit and do more damage. >Supposedly, M-16's to be used in the arctic needed a bit of extra twist >because of the greater air density. >Does anyone know whether the above is correct? Is low twist still used >on the M-16? On what other weapons? And how much does the damage >increase? It is correct that the bullet tumbled when entering flesh. This was a design feature, but also caused the round to lose forward velocity rapidly. The result was very little stopping power at longer ranges. I believe this (tumbling) is more a function of the bullet (a boattail) than of the rifling of the barrel. I do not have information on the twist for the original M16. However, the the M16A1 has a twist of 1:6, while the M16A2 has a twist of 1:9. This change in twist required a new round which is known as the SS109. previously the M16A1 used an M193. Other versions such as sniper models, XM-177E2, etc., may be different.
mjt@super.org (Michael J. Tighe) (06/22/89)
From: mjt@super.org (Michael J. Tighe) >>When the M-16 was first put into use, wasn't one of its characteristics >>an abnormally small amount of rifling twist? The idea was to make the round >>nearly unstable, so it would tumble when it hit and do more damage. >>Supposedly, M-16's to be used in the arctic needed a bit of extra twist >>because of the greater air density. >>Does anyone know whether the above is correct? Is low twist still used >>on the M-16? On what other weapons? Recently, I got do to some home-grown ballistics with several weapons, one of which was the (sarcasm mode on big-time) dreaded, evil-death, baby-killer, drug-scum (sarcasm mode off) Polytech AKS. One test consisted of the following. A large stump (approx 25 inches in diameter) set in front of 1/4 inch plywood. Another hardwood stump of similiar proportions was set behind the plywood. The AKS round went completely through the first stump, made a hole in the plywood (this indicated the attitude of the slug) and went at least two inches into the second stump! The plywood showed that in all cases the bullet was tumbling when it left the first stump. The second test consisted of shooting into a green, forked tree. Each fork was approx 8-10 inches in diameter. The slug passed through the first fork and lodged in the second fork, several inches deep. I dug the bullet out with my knife, and found it to be pointing toward me! It had went approx 4 inches into the second fork with the wrong end forward. These tests were performed on private property in my home town (hick town, USA). For you city folk, the wood being fired into was EXTREMELY hard wood. If you've never had the opportunity to shoot where you can just cut loose and enjoy, you haven't lived yet. Tom ---------------------------------------------------------------------
henry@zoo.toronto.edu (Henry Spencer) (06/23/89)
From: henry@zoo.toronto.edu (Henry Spencer) >It is correct that the bullet tumbled when entering flesh. This was a >design feature, but also caused the round to lose forward velocity rapidly. >The result was very little stopping power at longer ranges... The lack of long-range stopping power in Stoner's AR-15 was a conscious and deliberate tradeoff. Very little infantry combat ever happens at much more than baseball range, especially in places like Western Europe. And most soldiers can't hit anything at more than baseball range anyway, regardless of what scores they make on a dry, safe rifle range with no hostile fire. There are large differences between the official military mythology of infantry combat and the real thing. Stoner designed the rifle for the real thing. Henry Spencer at U of Toronto Zoology uunet!attcan!utzoo!henry henry@zoo.toronto.edu
ferguson@gorby.src.honeywell.com (Dennis Ferguson) (06/27/89)
From: ferguson@gorby.src.honeywell.com (Dennis Ferguson) In article <7700@cbnews.ATT.COM> henry@zoo.toronto.edu (Henry Spencer) writes: > >The lack of long-range stopping power in Stoner's AR-15 was a conscious and >deliberate tradeoff. Very little infantry combat ever happens at much more >than baseball range, especially in places like Western Europe. And most >soldiers can't hit anything at more than baseball range anyway, regardless >of what scores they make on a dry, safe rifle range with no hostile fire. >There are large differences between the official military mythology >of infantry combat and the real thing. Stoner designed the rifle for the >real thing. There is a well documented and explained summary of the M16 fiasco in James Fallows' book "National Defense" published in 1981. One chapter is devoted to how the special forces unknowingly instigated a major charter battle between the procurement offices and the Army bureau responsible for small arms development. Apparently, the bureau responsible for small arms development is run by people who still design weapons for WWII and is strongly infected with NIH. The conclusion that Fallows arrives at for the M16 (and other weapons as well) is that the major flaw in the US military is the procurement bureaus themselves.