Are we at the end of 2.25" (+/-) ?

[ColtSeavers]

Not that there's anything wrong with that. But after yet another life changing specialty chambering release (the 6mm arc), that's really just a rebadge, and the wildcats, I don't think there's anymore room for innovation left.

What strikes me the most though, is the innovation that's been put into finding out just how many combinations work within the constraints of bolt face diameter and magazine length seating, and the improvements that we've gained the advantage of as a whole because of them.

I have no issue with what we have so far, I personally went down the 6.8 tangent and have been pleased with what it offers me in addition to 5.56/.223, as I'm sure many others have been (or not) with their tangents of choice over the years. ETA: By tangent, i mean fun oddball cartridge to shoot in addition to 5.56 that fits within the ar15, not replacement.

However, I am saddened at the prospect of coming to the end of the road. I really only see wildcats being mainstreamed from this point on.

The only other option to me is abandoning the standardization, like the lwrc SIX8 lowers specifically lengthed to accomodate magpul polymer magazines that have to be larger due to strength issues with the redisgn to accomodate 6.8 ammo. At that point might as well go ar10 though.

What do you think?

[Hammer_Man]

Whatever the Army adopts next will be where the market goes. I don't see 6mm PRC, 6.8 SPC, or any other wildcat cartridge taking off, because there won't be a steady supply of Milsurp to stock the shelves.

[Eurodriver]

I didn’t realize people actually used any of those 6.8 cartridges. They all seem so pointless, I thought it was just Fudd gun writers for magazines trying to find something new to talk about.

[markm]

The constant quest for something better than 5.56mm is driven by people with bad ammo who can't shoot. Yeah, if you regularly shoot 55 gr junk, you might start to believe there are limits to the cartridge/platform... And with bad ammo, any caliber will suck.

[ColtSeavers]

Whatever the Army adopts next will be where the market goes. I don't see 6mm PRC, 6.8 SPC, or any other wildcat cartridge taking off, because there won't be a steady supply of Milsurp to stock the shelves.

Agreed, and as the military is hell bent on something other than 5.56, again, maybe this time is the time it actually happen, who knows (though I doubt it and am not advocating for it).

Also, for the record, I did not give up 5.56 for 6.8, I simply chose it as my oddball fun caliber to shoot in addition to 5.56.

[Dino11]

The military wanted a lightweight gun that would have good accuracy out beyond 1000 yards. The 5.56 round is only good out to 600 yards in the hands of a good shooter and terminal ballistics were greatly diminished at that distance. The enemy knows this and have been distancing themselves to stay out of range but they are still very close at 600 yards. The 6mm ARC is still super sonic at 1400 yards and has a very flat trajectory and shoots projectiles that can weigh in at 115 grains. It is also a very accurate round.

I believe this is going to be the new fad in the AR world, and we will see a lot of these in the near future. The price of the ammo will come down when other companies start producing it. And I heard that at least 20 companies have signed on to produce rifles and parts to build them.

I am on board with this as I have everything ordered to start a build, a lot of the stuff has already delivered, and I am hoping that the barrel will not be to far out. That is the only item that is being delayed.

[vicious_cb]

Funny even during the 6.X craze, they were still a very small percentage of the total sales and those still would fit on standard lowers. If you think changing small frame lower dimensions is the future then I hope you havent invested any money because its not going to catch on.

Sorry but the logistics train behind 5.56 is so strong there is ZERO reason for me to switch to anything else. If a new caliber comes out it better fit either a small frame AR form factor or a SR-25 form factor.

[MountainRaven]

The military wanted a lightweight gun that would have good accuracy out beyond 1000 yards. The 5.56 round is only good out to 600 yards in the hands of a good shooter and terminal ballistics were greatly diminished at that distance. The enemy knows this and have been distancing themselves to stay out of range but they are still very close at 600 yards. The 6mm ARC is still super sonic at 1400 yards and has a very flat trajectory and shoots projectiles that can weigh in at 115 grains. It is also a very accurate round.

The military is going to find out that the soldiers who can't hit anything at 300 meters with 5.56mm and an ACOG won't be able to hit anything at 1000 meters with 6mm ARC and an LPVO. They still won't hit anything at 300 meters with it, either.

It also doesn't change the facts that:
-These engagements are peculiar to a country that we're leaving.
-These engagements are occurring when the enemy is engaging American and allied troops with crew-served weapons (mortars, emplaced MGs, &c.).
-These enemies using crew-served weapons should be within range of American and allied crew-served weapons and/or CAS (and if they aren't, why aren't they?).
-Engagements in this country either occur at extremely long ranges (outside of the effective range of both enemy and friendly small arms fire) or extremely short ranges (where a 20" heavy-barrel 6mm ARC with a 5-25x50mm scope to shoot 1000+ meters is... inconvenient).

[308sako]

The constant quest for something better than 5.56mm is driven by people with bad ammo who can't shoot. Yeah, if you regularly shoot 55 gr junk, you might start to believe there are limits to the cartridge/platform... And with bad ammo, any caliber will suck.

There you go speaking gospel to the unwashed. I salute this post as one of the most concise truths seen upon the Web pages.

[Todd.K]

Let's not forget this all started back when "fragmentation range" was a thing and all the great barrier blind we have now wasn't.

With the 5.56 ammo available today there is little need to look further.

But you aren't wrong. I think caseless or a true intermediate size are where
worthwhile improvement will be.