drew458 sent me a copy of the original blueprint/dimensional schematic of the .280 brit cartridge, which i have written extensively about. not so long ago i developed a wildcat "jj's brit," with considerable input, comment and help from brit.
i make and load the wildcat, and have shot it in a rifle composed of my "lumber lower" and a conventional upper receiver, and functioning is very good, once the magazines get a little wear and slickening on them.
the original brit is very close to what i/we cooked up, so close that i am convinced that the brit would function very well in an ar-15, by the simple expedient of loading a relatively light bullet deeply into the case, not to exceed the nominal overall length as established for ar-15 rifles.
i think it a cartridge superior to the various .264"/6.5mm concoctions, for the purposes of close combat and for combat in the 300 to 400 yard range. for some purposes the 6.5's are pretty good, especially long to very long range target shooting. but, for combat, the brit is probably better.
6.5 enthusiasts should temper their enthusiasm a bit for the 6.5's as combat rounds, by a simple application of memory and historical judgment. huh?, you say. well, and the turn of the 19th century into the 20th (from the 1890's into the early 1900's), the 6.5mm cartridge was all the rage as a combat round, having been adopted roughly in that period by italy, austria, japan, portugal, sweden, i think perhaps roumania, and i think a couple others, which escape me. and, the united states navy adopted a far seeing rifle, the 6.5mm lee navy only to take it out of service with the adoption of the 7.62 krag jorgenson.
of those countries all of them switched to larger caliber rifles and/or loadings because the 6.5mm's lacked sure lethality, and the inability to immobilize an enemy with slightly marginal wounds. in simpler terms, the 6.5's lacked the killing power wanted by the armies using it. (and, the u.s. navy, for much the same reason.)
these countries went to larger caliber rounds, mainly the .308, .311 and .323 diameter rounds. and, when some of those countries adopted smaller rounds with lesser ballistic performance than what is now described as the "main battle rifle," even though adopted smaller cases with lesser powder charges, they stuck with the larger diameter & heavier bullets.
well, what difference does it make, you may ask. having never been shot with any of the rounds under discussion, i cannot lend you any reason based upon personal & anecdotal experience, i can only tell you what the military powers of the major combatant nations of the world did. and, that is clearly, that they abandoned the 6.5mm diameter bullet as a combat round, for the reasons stated.
some countries, denmark being a prime example, kept the 6.5mm round in the krag rifle for target shooting, which moving to an 8mm round & rifle intended for combat use, in the same rifle. it is difficult to conceive of any clearer example on the part of military thinkers that they viewed the 6.5mm bullet as insufficient to perform as desired in the fields of combat.
japan attempted the switch to a 7.7mm round during wwii, and italy attempted the same, adopted a 7.35mm round. portugal switched to the 8mm german round before wwii, though not involved in wwii but having considerable experience in her colonial possessions. sweden is the only country that i know of which used the 6.5mm through wwii, but, they never used the round in actual combat.
and, i would note, that the u.s. army though considering the adoption of a new service round, is likely viewed as adopting a 6.8mm round (.277 caliber, the same as used in the .270 winchester civilian round.) well, that's it.
have a nice day, and thanks for the read, if you got this far.
john jay @ 10.10.2019
Sadly I don't think there are any lethality studies at 400 meters. And there isn't much volley firing at 1200 yards in the military anymore. Nearly all rifle combat is at under 300 yards. For a reason! Without a good scope, can you even see a human target at that range, or get iron sites on target in the second or two you can safely stick up your head, aim and shoot, and not get shot yourself? Without a doubt, larger bullets make bigger holes, but usually take longer to get to those far targets. (extreme 19th century example:) Look at the .577/450 Martini-Henry. 480 grains of 20:1 lead at 1350fps. Double the energy of a .44 Magnum. Hit anything and it puts a fist sized hole out the back. Utterly lethal. But it takes all morning to get to the target, and the recoil has got to be severe. Same goes for 500 grains of .45-70 at about the same velocity and lead alloy. Kills the Indian and the horse he's riding, if he's still in the neighborhood by the time the bullet gets out there to 900 yards or so.
Maybe the answer is to give up the "Geneva Conventions" which we aren't even a signer of, and go back to bullets that actually work. A .243 hunting bullet can drop a deer on the spot at 400 yards, if it goes where you aim it. But FMJ is not a hunting bullet. It's a fool's projectile IMO.
It's a conundrum, I'll admit, but 110 grains of 24 caliber beats 70 grains of 22 caliber. Sure, 250 grains of 35 caliber beats them both, but pounds the daylights out of the shooter after about 8 shots. Or less.
Posted by: Drew458 | October 11, 2019 at 08:45 PM
drew:
actually, 400 grains at app. 1250-1300 per second out of a remington rolling block is a pretty mild load. not unpleasant at all.
on a good day, with the sun at you back, you can see the bullet approaching a 600 yard gong at a pretty high angle of attack out of a relatively good spotting scope.
and, a good shot w/ the vernier sight (made of steel, naturally), can be quite accurate, ... , but, you must know the range, and dial the sight in.
you are right about the speed of things .... a modern optic is very quick and quite serviceable to 300 to 400 yards or so, ... , ringing a 300 yard gong, say 10" in diameter, is not overly tough. from a bench, knowing the distance, and not being shot at. no anxiety there.
actually, taking a fmj round nose bullet in the kisser or in the chest is quite lethal, especially one of 30+ caliber or so ... it may not sound like much, but, a 150 grain bullet of such construction at 2200+ fps or so, is quite destructive on soft body organisms.
john
Posted by: john jay | October 16, 2019 at 05:07 PM
It continues to amaze me just how far ahead of it's time the .280 Brit was. Not just years, but generations.
The current darling cartridge of the bench rest shooting fraternity is the 6mm Dasher, which is an "improved" version of the 6mm BR. Aside from the caliber difference, the Dasher's dimensions are nearly identical to the .280 Brit. A hair less body taper, a body just 4/100ths longer, case length 0.14" shorter ... which means the Dasher is a short necked round. There is another flavor of it with a slightly longer neck which is better if you use a variety of bullets, without increasing OAL. Norma makes this as factory brass. My bet is Norma's case length is within a thou or two of the Brit's. The Dasher shoots one hole groups at >300m.
So what this means is that shortly after WWII the English developed a highly efficient mid-powered military cartridge with astounding accuracy potential. 70 years later and the target shooting world is in love with a minor variation of it. Awesome.
Posted by: Drew458 | October 23, 2019 at 09:06 AM
drew:
agreed. agreed. agreed. and, agreed.
a great cartridge. and, we can view the 7mm-08 rem as a "magnum" version. and, yes, i like the .284 caliber, very much.
john
Posted by: john jay | November 05, 2019 at 04:43 PM