This quote from the 300BLK thread got me thinking and raised a few questions.
I assume testing up to the SPC was done with FMJ.
The SPC and 7x46 were designed and tested with OTM.
Does the recent JAG approval of barrier blind bullets significantly change what the “best” assault rifle cartridge is, or would it just make it better?
Has a caliber, weight, and velocity of a barrier blind bullet that would have ideal terminal performance, increased range, and fit the AR mag size been researched?
Something like a barrier blind bullet in the 6 or 6.5 SPC?
“Does the recent JAG approval of barrier blind bullets significantly change what the “best” assault rifle cartridge is, or would it just make it better?”
Nope, just makes it better.
“Has a caliber, weight, and velocity of a barrier blind bullet that would have ideal terminal performance, increased range, and fit the AR mag size been researched?”
Yes, it is called 6.8 mm. If you expand beyond an M4 style platform, then your options open up to things like 7x46mm in a new platform or 7.62x51mm in something like the KAC SR25 EMC.
“Something like a barrier blind bullet in the 6 or 6.5 SPC?”
While 6 mm can be a substantial improvement over 5.56 mm in a short barrel PDW type weapon, I am not generaly too impressed with 6 mm in a general purpose carbine
With the heavier and higher BC bullets 7x46mm should be much better than 6.8SPC at longer ranges, with a good chance to do the job that needs to be done by both rifles and general purpose .30cal machine guns. Those 35lbs MGs would shrink considerabily if a cartridge like 7mm Murray would be used.
That" comonn receiver" SCAR 17 would be a sweet, easy to modify platform for 7x46mm.
The idea behing 7x46mm is that it could do both jobs decent. carabine and Machine Gun. For machine guns a little better armor penetration is needed to engage harder targets. Barier blind bullets help up to a point, but for general purpose MG you need a bit more energy/destructive power than small bullets can provide.
I think we should have had a longer 5.56mm in the first place.
Here’s an idea. It can have an MG loading with an AP core, or with a hollow tip to keep the center of gravity as far back as possible and yaw as soon as possible when hitting flesh.
There’s no replacement for displacement. You can tweak a 5.56 all you want. Just isn’t enough mass, cross section and energy to do all the jobs required by a main infantry cartridge. You should alsways leave some excess hitting power for times when you have less than ideal conditions.
One of the primary reasons why the US stuck with the 7.62 caliber long after WWII was its ability to punch through battlefield materials so well. Basically adhering to the concept that it’s better to have too much of something than not enough. The Brits got the sweet spot just right with the .280.
I look forward to getting a 7x46 rifle some day. Unfortunately it will be competing with the 7.62 NATO which is just so well established that it would take a massive military adoption of the 7mm to get it anywhere.
Nice idea, it would function perfectly in a Trapdoor Springfield.
Kidding aside, I think it was the Spanish who developed some cartridges with very long bullets that were fired at moderate velocities. The idea was to duplicate the recoil characteristics of an intermediate cartridge while at the same time duplicating the downrange ballistics (via very high sectional density) of a full power cartridge.
One of the primary reasons why the US stuck with the 7.62 caliber long after WWII was its ability to punch through battlefield materials so well.
I don’t believe there’s a doctrine in the US military today stating that a hand held bullet firing weapon, such as a rifle, must be able to penetrate “battlefield material”, like tree trunks and especially urban structural material. The only requirements are certain types of body armor, helmets, and light armor found on light vehicles.
The reason is that fire and maneuver override such a requirement. Furthermore, the materials seen on the field isn’t always what it seems. What appears to be a cinder block wall may have its cavities filled with adobe/mortar. What looks like a single layer brick wall may be two layers. And so on, and so on…
I would guess that even 50cal would have a problem with some of these unforseen barriers. In that case, 7.62x51mm or 30-06 would be laughable.
Not really. The Pedersen has a OAL that was actually longer than the 7.62 NATO, and a similar charge. Once again, a full power rifle cartridge with all the larger action requirements and larger magazine problems. The Pedersen also had a steep case taper similar to the .303 British making it unreliable in larger capacity box fed magazines requiring it to have an extreme feeding arc. The .280 British had a OAL almost exactly the same as the 7x46, similar power levels to the 7x46, and a case taper designed to be reliably fed in box magazines. If anything, the 7x46 is just an upgraded version of the .280 British which was conceived from scratch to be the ideal modern battlefield cartridge. So, as I stated earlier…the Brits got it right with the .280. It was designed around the larger capacity box fed assault rifle. The Pedersen was designed around a breech loading lower capacity battle rifle.
The Pedersen is an older design. When the 30-06 got shrunk we would have ended up with something very close to the .280 British instead of the 7.62x51 NATO if we had started with the Pedersen.
It’s interesting to think that if things had gone differently, we might still be using the same cartridge today, in a modern weapon system with improved powders and projectiles.
Yet we kept winning wars, go figure. Its also interesting, that for all the champions of the .30/7.62, who note we used it for well over 50 years, 60 if you include the Krag, it was apparently a choice of economics, for much of its history.
I say this, only, because its been noted that small arms are less and less of a factor on the battlefield. The “big ticket” items, generally have more impact on the outcome.
The fact that our troops are now confined by roe’s that prevent the full effectivness of those costly projects being brought to bare, are the result of politicians not Generals and engineers.
Early on, I was a fan of the .45 and 7.62, because thats what Guns and Ammo told me to like. Now, I know better.
I’m a big fan of the .40 & 5.56
The various 6 & 7’s look interesting, but I fear ultimately, they will meet the same fate as they did in the past, and for similiar reasons.
The various 6 & 7’s look interesting, but I fear ultimately, they will meet the same fate as they did in the past, and for similiar reasons.
I disagree with this. The goal has always been to have one front line infantry cartridge for the rifle, DMR, and universal MG. Having one round in all three systems be effective from the jungles of vietnam to the mountainous land of Afghanistan is a big deal.
If there ever is a opportunity for the US military to adopt such a cartridge, I think they will.
