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New military cartridge designs have traditionally driven new platforms.
We have small 5.56 and large 7.62 platforms
Is there something better?
There is always something better.
We are not even using 5.56 to its fullest because we are limited to fragmenting rounds.
The issue with a new cartridge, especially for the standard small arms is price, while something like the 7mm would be nice it just isn’t going to happen. The cost would be huge to get LC to retool, not only that but we would need a new rifle, training, manuals, spare parts, ect. Budget cuts are also abound as well as our governments willingness to waste money on new rifle trials that will ultimately give us nothing. We spend alot, are broke, and wont retool.
Then there is also NATO we would have to deal with, there are alot of NATO miltaries that are just now switching to 5.56, I don’t see them being on board for a new caliber.
So in short, there is better(even in 5.56), it would be nice to have, but it isn’t going to happen.
I tell you though, if we really set our minds to it and wanted it bad enough, we could do it. We did it in vietnam and we could do it now, instead we are more worried about finding a uber reliable, never needs lube or cleaning rifle that shoots the same 5.56 as what we have…
ETA: if we would focus on the PiP for the M4 and M16 instead of spending money on carbine trials I bet we could do it. I mean look at how much we have spent over the years on failed replacements for the M16FOW. If we would have spent that money on a new caliber study, one that determines what would be best for our soldiers we could have a 7x46 round as the standard.
Once we determine what round would be best we then see what soldiers need and do not need in a rifle. Make it a FOW’s, one that is easily adapted and changed to fit the users(so PDW for tank crews, 14" for standard soldier, 18" for DMR) make a FOW’s that is reliable, with at least 20,000 rounds part life and one that shares 90-95% parts across the system. Main things that would need to be changed would be barrels and stocks between the different rolls.
That would also keep costs down in the long run by only having to buy one type of bolt, bolt carrier, upper, lower, and only 3-4 different types of barrels and stocks.
Also make the FOW capable of LMG type fire that way you could also have parts for the LMG that is interchangeable for the carbine, PDW, and DMR.
All of it is possible but we will never do it because our priorities are so screwed up. If you got the best minds in the industry together they could make a whole FOW’s.
If we take non-Nato options out of the equation, I see a promise in small (relatively) 7.62 carbines.
I think that the Scar-H and Robinson XCR-M are a good place to start, with a dash of the KAC EMC, LMT MWS, and LaRue PredatOBR/PredatAR.
While 7.62 guns have issues with barrels under 16", I don’t think that it’s a ridiculous stretch to think that ammo manufacturers could play with powders, velocities, and projectile weights to make them softer shooting and short barrel friendly while retaining much of what makes the 7.62 as effective as it is.
My perspective on this is for military use.
I don’t personally feel the need to replace my ARs with 7.62 guns, though I wouldn’t mind having one or two.
If I am going to deviate from the AR platform, I want it to be for tangible, easily articulated reasons. I want better ergonomics, complete ambidexterity, easier one-handed use, and increased performance where it matters (precision, recoil, comfort, speed, terminal effect).
One concern would be the relative function of this new lower powered ammo. There is no advantage to ammo being the same size if it’s not interchangeable.
I’m talking more along the Mk319 route.
I’ve always had a feeling that an intermediate magwell (between the AR-15 and SR-25 size) in an intermediate caliber (something between 6.5 and 7.9mm caliber) could conceivably embody everything we’re after - think of a 6.8SPC with the reach of a .260Rem, I think that could be possible, and workable with a reliable, moderate weight system holding 25 rounds.
Nothing would stop this from being possible with modular magwell systems either.
I think there’s still a bit of folly trying to marry up the PDW to too many item from MMG and precision weapon systems in terms of parts commonality, but if we decide to just hold onto a big FOW solution around two magwells, that means that Mk18 can be viable as a PDW, M4’s with some minor improvements as all around fighting weapons, and an AR-10 variant with M240’s as the heavier squad level weaponry.
The above might seem totally passe’, but in terms of development cost in a politically austere DoD funding environment is probably the best we could hope for.
That’s pretty much the 7mm Murray.
With LWRC’s new 6.8 upper, lower and mags, you may be able to build a 6.5 based on the 6.8 that would work very well.
I tend to agree the 7X47 would be an optimal solution if you were looking for one cartridge to do it all. I think the 6.8 is fairly close though…
An LMG by definition sits on a tripod. There is no point using a box fed weapon like that. And any caliber as large as discussed will be too large for use in a PDW. Since 90% of the military would use a PDW there’s little point to making compromises there.
Specifically, what combination of features are you thinking?
Agreed. The AR sets the bar pretty high in most of these categories.
I always thought the SCAR-H/Mk17 would be a good platform to develop the round with because you could build a lower to whatever dimensions you needed.
Realistically I don’t see any change until LSAT finishes testing ct/cl ammo.
I would definately be in the minority, but I think a caseless 7mm bullpup with modular quick change barrels like the AUG would be the shit.
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Not that some work can’t be done to make it lighter recoil. But there will be a limit for function in existing 7.62 rifles and not beating up the new one too bad by shooting M80.
Are there issues in general with getting 7.62 rifles to run well with a variety of ammo? More so than 5.56 / .223 or pretty much the same?
7.62 ARs are more finicky but I can’t speak to other designs.
Wonder if the New Colt /KAC/LMT could come up with a Magazine adaptor for its 901/EMC/MWS to adapt to the 7x46 murray round. I could see using existing 7.62 lowers with 25/30 round mags for the 7x46.
Get the weight down to between the 7.62 ECC and a 5.56/ 16 inch recce rifle,
Do you mean ergonomic, system design, performance, or caliber aspects? Or a combination of those aspects?
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It depends on the gas system and barrel length, like the AR-15.
Short barrels with little dwell and long gas systems are more sensitive to changes in bullet weight and burn rate that change the pressure and duration at the gas port.
^^ Yes.
From your previous post (below) it sounded like you’ve done quite a bit of thinking on the subject and I’m interested in hearing the details of your concept.
6.86x41. Get it done.
I agree with this basic premise.
I assume it had to be designed with the longest round ( 7.62 ) first and 5.56 length made to work.
In order to use different mags, the lower has to be different.
There are one or two issues that come up when looking at a platform that supports multiple length cartridges.
How does the design accommodate the length variation?
Do you keep the location of the front of the mag and the fire control group fixed?
The bolt carrier could be the same, with the exception of a way to limit/shorten the recoil stroke slightly.
The 5.56 version would have “extra” space between the trigger guard and the back of the mag.
It would be slightly longer and heavier than it would otherwise need to be.
At that point you have to ask: is it worth it?
Why not just make a dedicated weapon?
Parts commonality on the manufacturing side would be great, but what does that translate into for the end user?