My copy of the June 2005 American Rifleman arrived today. I scanned it briefly, and found on p.51 a puzzling statement in a sidebar titled "6.8x43 mm SPC: Fatter is More Chic". The sidebar describes the development of the cartridge and its introduction by Remington to the civilian market.
The puzzling statement starts the third paragraph: "The .30 Remington case, which is slightly thicker than the 5.56 case, but is exactly cylindrical, serves as the basis for the new cartridge." (Emphasis added.)
I assume that "thicker" refers to diameter. What I can't comprehend is the description of the .30 Remington as being "exactly cylindrical". The context provides me with no clues.
According to a SAAMI drawing I have, the .30 Rem tapers from about .422 inches at the head to about .402 at the shoulder. That would seem to make it conical, rather than cylindrical.
Cartridges that SAAMI specifies as being cylindrical include the .25 ACP, .32 S&W, .357 Mag, .38 Short Colt, .38 Special, .38 ACP & .38 Super, .45 Colt, and a few other cartridges designed for pistols and revolvers.
I'm hoping somebody can tell me either of the following:
(A) what feature of the .30 Remington case makes it (and not the 5.56 case) "exactly cylindrical"; or
(B) What did the author mean to say? That the Remington case was rimless?
The drawing (attached) of the .30 Remington in my book is based on dimensions in the SAAMI drawing. Not only is the body of the case tapered (not cylindiical), the case is also obviously necked.
Conclusion? Whoever writes that it's cylindrical has his cylindrical head on crooked. If his Editor deleted almost or nearly where the writer had written "almost ... " or "nearly cylindrical," that wouldn't be the first or the worst example of an "Editor" ruining a writer's correct statement.
Maybe the writer merely looked at the .30 Remington case, which does indeed look as though its body is cylindrical (thin excuse).
.
"Good enough" isn't.
Always take your responsibilities seriously but never yourself.
The AR referred to the case as cylindrical to distinguish it from all the rhomboidal, trapezoidal, and sphero-conoidal cases jangling about the Pentagon. What really baffles me is, we've been shooting people with the 5.56mm for 40 years. NOW we discover it's underpowered?
I would not want to be shot by a 223 or 6.8 spc but if I had to chose one over the other for an m16 application, I would take the 6.8 with larger payload.
