[Modern Firepower] Technothriller gear for secret DHS team in 2017

[Icelander]

Originally Posted by acrosome

Icelander, have you ever considered that your GURPS habit has lead you to be unusually familiar with U.S. gun culture? To a level that might disturb a lot of your countrymen? :)

Originally Posted by Þorkell

Oh, do tell...

Ironically, I still don't own any firearms, unlike my father, grandfather, step-grandfather*, kid brother and several friends. Most of them don't play any RPGs and at least two of them, my kid brother and my best friend** read gun magazines and tacti-cool spec-ops memoirs or training literature for fun.***

So, you know, Iceland isn't entirely firearms-free and, in fact, my experience is that adult men usually know how to shoot and have at least a rifle and a shotgun. One of my friends even manages to get a reindeer most years (very limited number of licenses), which demands a level of patience with bureaucracy that argues a great passion for hunting.

It's a hotly debated subject, with the methods used to measure not always fully compatible, but most sources seem to agree that Iceland has a very high rate of firearm ownership per household. Less than the US, more than almost all EU states, South or Central American ones or Asian countries.

I keep meaning to find the time and money to shoot more and get my own guns, but I never seem to have enough to spare of either. Breaking both elbows a couple of years ago didn't help, as there are still bone fragments in the joints that can't help but make shooting difficult and painful.

Will respond to specific points later, as patience with tapping on a mobile screen is exhausted.

* Father of dad's second wife. Icelandic family structure. Anyway, he had the most guns by far, around 100 in a purpose-built gun cellar (along with tools, reloading presses and a functioning replica of a 19th century cannon, smaller scale, but still 1/2-lb ball). After moving, he trimmed down the collection a lot.
**Cop, arrest technique instructor, riot/tactical team. Has recently taken up travelling to the US to attend tactical shooting seminars a couple of times a year.
***Whereas I, very sensibly, only read such stuff for research. ;-)

[Icelander]

Originally Posted by acrosome

It's pretty easy to change the bottom metal on most "hunting rifles" to one that takes AICS magazines, [...] Voila, you have 10-round detachable magazines on a hunting rifle. [...].

Yeah, originally I had almost totally ruled-out any bolt-action weapon, for the simple and selfish reason that Chase Taylor, the character I am playing in the campaign*, has heavily improved Enhanced Tracking, which he can do while taking other actions, and both the Fast-Firing and the Quick-Shot techniques, allowing him to make two different aimed attacks per second, firing up to 9 rounds per second (from a semi-auto), split between the two targets, for as long as there is ammo in his weapon.

Of course, I realise that there are a lot of NPCs with supersoldier abilities, but perhaps not the incredible shooting abilities that Taylor has. And we've also gained another PC who is special-ops capable, but merely extraordinarily human-level skilled, not actually inhumanly skilled.

So you are quite right in suggesting that some supersoldiers may find bolt-action rifles a good fit for their skill set and tactical requirements. Especially those who may have cut ties with the military and government and are on the run from the US (and possibly other governments). It may be easier to obtain bolt-action rifles in Latin America (or elsewhere in the world) than semi-automatic ones and many of the supersoldiers will have good Armoury skill.**

*In addition to my duties as Assistant GM for Research, Realism and Rules Stuff (Especially Technothriller and Guncraft Stuff).
**Special Forces Weapon Sergeants tend to be good at that. A few of the supersoldiers who are potentially on the loose worked with AMU, took part in JSOC or SOCOM testing of sniper rifles and/or spent part of their careers as armourers with 7th SFG (A) or Delta.

Originally Posted by acrosome

But any .308 magazine will also take anything derived from a .308 parent cartridge, like .[...]. So really, to get a highly accurate 20-round semiautomatic in such calibers you just need to re-barrel an AR-10, which is also almost trivial.

Indeed. I've pretty much made up my mind that I'll need to stat out an AR-10 rifle with an accurised upper in 6.5 Creedmoor or a wildcat in 6mm. That would probably be a Bulk -5 rifle (Bulk -5* if I can find a plausible way to combine a folding stock with good shooting at over half a mile), so the barrel can be up to 22" or so if necessary.

I'm currently studying all sorts of ballistics reports looking to see if I can find a round that will perform well at up to 1,000 yards from a 14.5" barrel. That would be for a Bulk -4 'do anything' super-carbine. What's really crucial is that it retains velocity well enough not to enter the transonic range until after the 1,000 yard point.

Originally Posted by acrosome

Well, assuming that you're using loads without too long of an overall length, but I know that .338 and .358 ARs have been made, by Wilson Tactical if no one else.

What really surprised me when I started looking into the issue is that overall length often limits the use of the longer, heavier, more aerodynamic bullets available in a given caliber in semi-automatic, magazine-fed rifles.

So, yeah, there are .308 Winchester and .30-06 handloads with very good ballistics and many semi-automatic battle rifles exist in these calibers, but if you load the 190-220 grain bullets that allow for high SD and BC and good long-range performance, you can't feed them from magazines or chamber them reliably in anything but what is effectively a new design of a semi-automatic, one bearing only a superficial similarity to the original weapon.*

This makes various rounds in 6-6.5 designed for modern propellants and long, low-drag bullets attractive.

*And, generally, one which is not available without a hefty investment in resources and time. Even then, research indicates that what are presumably expert gunsmiths and/or engineers with name companies often find it difficult to ensure reliable feeding in semi-automatics chambered for rounds loaded with very long bullets.

Originally Posted by acrosome

Get a barrel wrench from Brownells and change them yourself.

Yeah. Any character I'm wondering about this for will have Armoury at skill 12+ and several have it at expert level, 14-18. Chase Taylor, for examle, has Armoury -18, handloads his ammo, checks over every part of any weapon his team is going to be using and usually fine-tunes them.

Originally Posted by acrosome

The .260 Remington is very popular in ARs, and is currently fighting 6.5mm Creedmor for market supremacy. (The 6.5mm Lapua seems to be disappearing from the US market.)

I'd say that events in 2017 mean that the smart money is on 6.5 Creedmoor winning out. Most winners at long range shooting matches are using Creedmoor, Lapua has started making brass for 6.5 Creedmoor and Hornady is even starting to sell 6mm Creedmoor, derived from the larger round.

Originally Posted by acrosome

The .243 has the problem of short barrel life so it has lost popularity.

That is surely a fairly important real-world concern, but how often do people living the desperado lives of adventuring PCs ever manage to keep a gun long enough to shoot even a 1,000 rounds through a barrel, let alone more?

Sure, there's training and improving skills and such, but surely, then it's just adding 10 to 40 cents to cost per round*, which, while not always ignorable, can still actually be economic if one round is much more expensive to reload than the other.

*Good match barrels can be had for under $400 and if the shooter is a highly qualified armourer, he doesn't have to pay any other costs than buying the barrel.

Originally Posted by acrosome

And then remember, all you need to do to change calibers on an AR is to swap the upper, so you could have a quiver full of uppers of various calibers.

While I'm sure changing the upper can be done without affecting the normal combat accuracy of firearms all that much, I've always had a sneaking suspicion that it must have some effect on mechanical accuracy. At minimum, you'd need to zero the weapon again before shooting to a fraction of MoA accuracy at a thousand yards.

Which is just fine, for most users, but is pretty hard to accomplish during many adventuring scenarios, where characters may be trying to keep their locations concealed from the opposition or something similar.

This is not to say that I can't imagine an adventuring situation where PCs or important NPCs deploy with a AR-15/AR-10 type rifle and several uppers; maybe a short-barrelled (10.5"-12") CQC upper in 5.56x45mm, 6.8 SPC or .300 BLK, a carbine barrel length (14.5"-16") one in 5.56x45mm, .224 Valkyrie, 6.5mm Grendel or some sort of wildcat in 6mm made from Grendel or SPC casings, and an SPR-esque designated marksman rifle length (18"-22") one in the best available long range chambering for the underlying rifle.

I just haven't had any players show interest in it. And, as for my own character in Jade Serenity, Chase Taylor would almost certainly consider it too fiddly for field use to carry several uppers and instead choose to go with one chambering and configuration for the mission, perhaps a less optimal round for each individual role, but which he found 'good enough'.

Special Agent Ilana Rubio (PC) seems to like carrying several guns rather than several uppers, but then, she has a vehicle for now...

Originally Posted by acrosome

Also, for the record, my vote is that anything from Wilson Combat deserves the Fine rating.

I would tend to agree, but I've actually never seen any carbine length AR-15 written up as Fine (Accurate) in GURPS.

In real life, of course, there are plenty of 14.5-inch barrel carbines that can match or exceed the mechanical accuracy of 20-inch AR-15s, but the issue is that GURPS Acc seems to be a composite number that also measures how flat-shooting a given weapon is, some generic estimate of how shootable it is and even how well the bullet assumed for the standard load handles wind and other conditions in long-range shooting.

Military issue .50 BMG isn't necessarily the most inherently accurate load in the world, but it gets Acc 6 in GURPS because it retains velocity and a fairly predictable trajectory out to a very long range. By the same token, shorter barrels don't necessarily interfere with mechanical accuracy, they just provide a shorter sight radius* and, importantly, lower starting velocity, which means that it will, among other complex external ballistics issues, have more drop, probably be more affected by wind and hit the transonic zone earlier.

*Irrelevant with good optics, anyway.

Originally Posted by acrosome

Personally, if I wanted a hard-hitting long range AR-15 I'd be far more interested in 6.5mm Grendel than .224 Valkyrie. But I'm a 6.5mm fanboi.

I was initially concerned that because the 6.5 Grendel was designed for 24" barrels, it would yield little impressive from a CQC or carbine length barrel except a huge fireball and noise from unburned powder.

Checking ballistics reports reveals that it is still superior to 5.56x45mm from a 14.5-inch barrel, but perhaps not by enough to matter, especially if you compare it to the newest Mk 262 loads.

Originally Posted by acrosome

The .224 does have impressive external ballistics, granted, but I bet it burns through barrels at a startling rate.

I'm really looking for a 'super-5.56mm carbine', something designed for optimal long range performance from a 14.5-inch barrel AR-15 platform.

[Kalzazz]

Are any variants of the FN FAL liable to work? It seems to be produced in myriad designs

[Icelander]

Originally Posted by Kalzazz

The gunsmith I linked to had made a high capacity .270 Win magazine for his Remington 7600

Numerous 8-10 round magazines for the 7600 exist

Very true.

Originally Posted by Kalzazz

So it would be far from an insurmountable challenge I expect to make a 20 round magazine

It would not be difficult at all for .308/7.62x51mm or any chamberings derived from it, of roughly the same dimensions.

The problems would be with cartridges that are much longer or thicker than .308 Winchester. .300 Win Mag are 12% thicker and longer than .308 cartridges. .300 Weatherby Magnums and .300 Remington Ultra Magnum are even larger, not to mention .338 Lapua Magnum.

What that means is that magnum rounds often cannot be double-stacked in magazines that fit the actions of most rifles. And a 20-rd single-stacked magazine would be extremely long and unwieldy.

As noted, there are some extremely custom semi-automatic magazine-fed rifles that chamber .300 Win Mag or .338 Lapua Magnum in 10-rd magazines., but these have to be custom built to accomodate magazines that are much thicker than those most rifles are designed for. As a result, they are wallet-achingly expensive and often cannot be obtained without months or even years of waiting.

I'm trying to find some good cartridges for accuracy and nice ballistic qualities at very long range which aren't all that much larger than .308 Winchester, or, at the very least, have been proven to work reliably in some design of double-stacked magazines that could be copied by a qualified gunsmith character (Armoury at skill 14+, as noted several will have skill 16-18).

Originally Posted by Kalzazz

I'd guess probably be a Armoury Small arms with a say -4 penalty and a machinist check if I was forced to guess

I wouldn't disagree on the penalty when it comes to designing a double-stack magazine that feeds reliably in a semi-auto, for rounds that are typically never used in such a thing.

The relationship between Machinist and Armoury (Small Arms) puzzles me a bit. There's no default from Armoury to Machinist and it would be theoretically possible in GURPS for someone to be an expert or even master gunsmith (skill 14-15 or even skill 18-20), but have Machinist at skill -5, i.e. default from IQ 10. That doesn't seem to match reality, as much of what actual gunsmiths do involves using machinist's tools to do pretty much the same things machinists do.

I'd have some default from Armoury (Small Arms) to Machinist, at least. Maybe a -4 or so.

Originally Posted by Kalzazz

Are any variants of the FN FAL liable to work? It seems to be produced in myriad designs

As far as I know, they would work as well as the AR-10.

Of course, there might well be some real-world reason why the FN FAL design might be superior or inferior to be used as the basis for a rifle firing a long range cartridge than the AR-10, in which case I'd be interested in hearing it.

Characters with high Armoury and Guns skills should be able to wow and entertain their fellow players and audience by reciting detailed technothriller-y reasons for why they chose their particular weapon and what incredibly skilled feats of gunsmithing they performed, even if the game stats are functionally the same.

That entertains me, at least. I could read loving descriptions of firearm or other tactical gear technical details in a good technothriller for days, stopping only to be jarred and disappointed whenever I come across some detail that I know to be wrong.

[acrosome]

Originally Posted by Icelander

Bulk -5* if I can find a plausible way to combine a folding stock with good shooting at over half a mile), so the barrel can be up to 22" or so if necessary.

Ugh. I know of AR15's with alternate recoil systems that allow foldable stocks (the SIG-Sauer MCX comes to mind but there are others) but not AR10s. Let me look around. FALs have a reputation for poor accuracy, but maybe some HK rifle? Gunsmithing either of those is somewhat more complicated than an AR, though.

Oh, the SCAR-H has a folding stock, and the US military is adopting a marksman version. (And there is even talk of adopting a 6.5mm caliber...) Would that work for you? The US special ops community seem to have decided that he SCAR-L isn't all it was cracked up to be (some sort of issue with short-stroking in certain situations) but they still like the SCAR-H.

And there is this thing.

Originally Posted by Icelander

I'm currently studying all sorts of ballistics reports looking to see if I can find a round that will perform well at up to 1,000 yards from a 14.5" barrel. That would be for a Bulk -4 'do anything' super-carbine. What's really crucial is that it retains velocity well enough not to enter the transonic range until after the 1,000 yard point.

I don't want to go all negative on you, but... that's a tall order. :)

Originally Posted by Icelander

What really surprised me when I started looking into the issue is that overall length often limits the use of the longer, heavier, more aerodynamic bullets available in a given caliber in semi-automatic, magazine-fed rifles.

So, yeah, there are .308 Winchester and .30-06 handloads with very good ballistics and many semi-automatic battle rifles exist in these calibers, but if you load the 190-220 grain bullets that allow for high SD and BC and good long-range performance, you can't feed them from magazines or chamber them reliably in anything but what is effectively a new design of a semi-automatic, one bearing only a superficial similarity to the original weapon.*

This makes various rounds in 6-6.5 designed for modern propellants and long, low-drag bullets attractive.

You're preaching to the choir, Brother. I'm a 6.5mm fanboi. My .260 is like shooting a laser.

Originally Posted by Icelander

I'm really looking for a 'super-5.56mm carbine', something designed for optimal long range performance from a 14.5-inch barrel AR-15 platform.

Originally Posted by Icelander

I'm trying to find some good cartridges for accuracy and nice ballistic qualities at very long range which aren't all that much larger than .308 Winchester, or, at the very least, have been proven to work reliably in some design of double-stacked magazines that could be copied by a qualified gunsmith character (Armoury at skill 14+, as noted several will have skill 16-18).

Also a tall order. That's sort of contrary to the whole point of a short 14.5-inch barrel, and the people who have designed rounds for them (e.g. 6.8mm SPC) definitely had different goals. I really can't think of a round with that design goal. Even .224 Valkyrie was made for longer barrels. I think the closest you can get (or at least the best I can think of off the top of my head) is an AR10 or SCAR-H in some 6.5mm caliber. And since a fair number of the special people are carrying 7.62mm rifles nowadays I don't think that's much of a stretch.

If you want the accuracy at those ranges, you're simply going to need a long range rifle.

[Anthony]

If you really want high velocity and high sectional density out of a short barrel, you're probably going to need saboted ammunition (it's possible some lunatic has worked out a .50 caliber short barrel that can fire M903 SLAP...)

[Icelander]

Originally Posted by Anthony

If you really want high velocity and high sectional density out of a short barrel, you're probably going to need saboted ammunition (it's possible some lunatic has worked out a .50 caliber short barrel that can fire M903 SLAP...)

Ah, excellent point.

And, of course, the Swedish military actually issues a 7.62x51mm saboted round to their marksmen, so there is data on how such loads function. Accuracy is less than with match loads, but the flatter trajectory, less wind drift and longer range before entering the transonic envelope might well make up for it.

Maybe an ideal supersoldier DMR round would be a saboted high ballistic coefficient bullet in 6.5mm fired from a 7.62x51mm cartridge. That does sound like it would call for some careful engineering, as opposed to merely handloading (.223 saboted bullets in .308 can be handloaded, but I'm not sure how thin and light the sabot can be without large and expensive precision machinery).

On the other hand, various cartridges that neck down .30 caliber brass to shoot 6-6.5mm bullets pretty much accomplish the same goal and get match accuracy (at the cost of rebarrelling and sometimes other modifications to the rifle). So I guess that for any real results, you'd need a very low diameter projectile, smaller than 5mm.

The real world reason saboted smallarms rounds are rarely used is, of course, that sometimes the sabots break down, leaving a subcaliber projectile carooming around in your fancy barrel, potentially ruining it. PCs and their supersoldier allies/foes/rivals may tend to have a higher tolerence for risks of ruining their nice things than real militaries (or sporting shooters), as their lifestyle already assumes most nice things will get ruined on a regular basis.

[warellis]

Originally Posted by Anthony

If you really want high velocity and high sectional density out of a short barrel, you're probably going to need saboted ammunition (it's possible some lunatic has worked out a .50 caliber short barrel that can fire M903 SLAP...)

The sabots would get caught on the muzzle brake and screw with accuracy I imagine.

[DouglasCole]

So, why the focus on 14.5" barrel? Why not use a long barrel (say, 18-22") but mate it with a bullpup receiver?

My M17S from bushmaster has a 21.5" barrel in a 30" weapon. It's MUCH shorter than my 16" barrel AR15.

The Kel-Tec RFB is a 7.62x51mm platform that is only 32" overall for a 24" barrel.

The Desert Tech MDR platform seems built for what you need. It can be quick-converted from 7.62x51mm to 5.56x45mm with some part-swaps, the thing is only 26.2" long with a 16" barrel. Mounting a 20" barrel would make the thing a still-very-handy 30" long.

Anyway, if you want "1000yds" and "powerful" and "carbine" then you're looking at a bullpup.

[Icelander]

Originally Posted by acrosome

Ugh. I know of AR15's with alternate recoil systems that allow foldable stocks (the SIG-Sauer MCX comes to mind but there are others) but not AR10s. Let me look around. FALs have a reputation for poor accuracy, but maybe some HK rifle? Gunsmithing either of those is somewhat more complicated than an AR, though.

Well, for an AR-15 type rifle, you can always put a Law Tactical folding stock adapter on it. See manufacturer's page. They appear to work adequately enough.

You can actually mount them on AR-10 rifles as well. That may or may not work as well as mounting them on the AR-15 platform.

My main concern here is that even if adding such an adapter has little impact on accuracy at typical shooting ranges, precision rifles are usually engineered to avoid any possibility of give or loose tolerances. Pretty much any stock will be sufficient for minute-of-bad-guy at under 100 yards and any reasonably well-designed one will suffice for the same accuracy at up to 300 yards. But I haven't seen many precision rifles meant to shoot out to 1,000 yards or even further that don't have stocks designed expressly for that purpose, with zero possibility that the stock will move slightly around while the shooter is aiming.

Let's say that if I were to allow that a folding stock could coexist with the best possible GURPS Acc allowed at a given Bulk, I'd probably want it to be a very solidly engineered one. A $200-$260 piece of metal that is essentially a work-around for a rifle that isn't designed for a folding stock may qualify, but I'd want convincing that it was the absolute top of the line in mechanisms that allow weapons to be carried at one Bulk lower.

Of course, just having a master gunsmith build essentially the same doodad, but with much more care and precision, at a cost matching Fine or Very Fine (Accurate), i.e. $350 for a Fine version (allowing use with Fine (Accurate) rifles) and around $1,000 for a Very Fine one (ditto for Very Fine (Accurate), might be plausible enough.

Originally Posted by acrosome

Oh, the SCAR-H has a folding stock, and the US military is adopting a marksman version. (And there is even talk of adopting a 6.5mm caliber...) Would that work for you? The US special ops community seem to have decided that he SCAR-L isn't all it was cracked up to be (some sort of issue with short-stroking in certain situations) but they still like the SCAR-H.

And there is this thing.

Oh, indeed.

Something based on this, but in 6.5 Creedmoor, might be the gold standard for a DMR for supersoldiers who still have access to governmentally supported Tier One special operations units level resources.

In other words, the secret black ops people from the (almost certainly*) still extant DoD supersoldier program, who oppose the Onyx Rain faction trying to contain the fallout from the failed Jade Serenity program from the 90s. The scarily competent, precision-gengineered modern supersoldiers who will one day be sent to kill the outmoded, unpredictably powered PCs, their friends, their allies and even their enemies.

*By every narrative law of both technothriller and superhero fiction.

Originally Posted by acrosome

You're preaching to the choir, Brother. I'm a 6.5mm fanboi. My .260 is like shooting a laser.

Everything I've found strongly supports a 6.5mm bullet of 123-142 grains, fired from a casing that will feed in a weapon designed for the 7.62x51mm NATO with minimal changes as the optimal choice for a supersoldier designated marksman rifle, i.e. the Bulk -5 rifle with a barrel of 18"-22". There might be arguments in favour of a 6mm bullet in 103-115 grains fired from a similar casing, though.

I'm still trying to find the optimal chambering for the 'do everything' super carbine, i.e. Bulk -4 or -4*, with a barrel no longer than 14.5" (see later reply to Douglas Cole about the possibilities of a bullpup for that role for an alternate build, though).

Leading candidates for a load so far are: a) some variety of 5.56x45mm, using one of the more modern loads with a fairly high BC bullet of 73-77 grains; b) .224 Valkyrie; or c) a handload or even a wildcat cartridge firing a either a .224 caliber bullet in 73-100 grains or a 6mm bullet in 80-105 grains from a casing that will feed in an AR-15 platform carbine.

Originally Posted by acrosome

I don't want to go all negative on you, but... that's a tall order. :)

Originally Posted by acrosome

Also a tall order. That's sort of contrary to the whole point of a short 14.5-inch barrel, and the people who have designed rounds for them (e.g. 6.8mm SPC) definitely had different goals. I really can't think of a round with that design goal. Even .224 Valkyrie was made for longer barrels.

Oh, I know it's a tall order.

To be clear, I'm not expecting to be able to match the ballistics of a 6.5 Creedmoor from a 22" barrel precision rifle with any kind of handy AR-15 type carbine. Rather, I'm designing two different types of weapons, for two different (albeit somewhat similar) tactical roles.[1]

First, I'm looking for a designated marksman rifle with no more than Bulk -5, with better performance at 900-1,000+ yards than the 7.62x51mm (flatter trajectory, less wind drift and a longer range until it goes transonic), semi-automatic or otherwise allowing RoF 2+, with a detachable magazine capacity of 10+ (the higher the better, but much more than 20-rd would probably impact Bulk). This can be a rifle with a barrel length of up to 22", or even a couple of inches more, depending on ergonomics and design.

I think I've already found the desired chambering, in 6.5 Creedmoor, but am still looking at what necking down to 6mm gives me (for one, allowing longer bullets to feed more reliably in semi-autos, it seems).

Second, I'm looking for a 'do anything' super-carbine. This would have Bulk -4 or even Bulk -4* and would ideally be close to the handling of the M4, various shorter 'Recce rifles' or the HK416/HK417 or FN SCAR-L/SCAR-H with the regular barrels. If possible, of course, matching the OAL and handling of something like the CQC barrels of the FN SCAR and HK416/HK417 or the Colt Commando, Mk 18 and similar short M4 types would be magical, but such short barrels would lose far too much velocity.

In a perfect world, it would remain comfortably supersonic until at least 1,000 yards and be able to shoot accurately until that range. If that turns out to be impossible, it still has to beat the effective range of the 5.56x45mm NATO from a 20" barrel rifle, which a number of loadings in several chamberings can actually do, even from shorter barrels.

Obviously, the reason to carry such a weapon at all, instead of a precision rifle, is that it would be lighter, handier, more concealable and more useful at typical short combat ranges. So it needs RoF 3+, Shots 30+ and all that typical assault rifle/carbine good stuff. But because the shooter might well have the ability to make accurate shots at up to 1,000 yards if the mechanical accuracy and the external ballistics of his weapon system allow, it makes sense to think about allowing the carbine carried to have an alternate role as a long-distance platform out to the longest range practical without compromising other desired characteristics.

[1] Technically, I'd also like a third weapon system, a real supersoldier sniper round, well outranging the 6.5 Creedmoor. Semi-automatic, Shots 8-10(3), Bulk -5 (unlikely) or Bulk -6. Magnum 7mm, .30 caliber or .338 caliber.

Originally Posted by acrosome

I think the closest you can get (or at least the best I can think of off the top of my head) is an AR10 or SCAR-H in some 6.5mm caliber. And since a fair number of the special people are carrying 7.62mm rifles nowadays I don't think that's much of a stretch.

Agreed.

From 24" and 26" test barrels, 6.5 Creedmoor loads are often accurate at well over 1,000 yards and remain comfortably supersonic until entering the transonic zone at between 1,150 yards and 1,700 yards, depending on the bullet used and how hot the load is.

From a 22" barrel, accurate shooting with several well regarded loadings at up to 1,400 yards, at which time it goes transonic, is well within the realms of possibility (at least as far as the weapon system goes, most human shooters will never care about this level of performance).

Even with a 16.5" barrel, it seems that 1,000-1,100 yards before the bullet goes transonic might be reasonable. I still haven't found good data for shorter barrels than that, probably for the reason that it would require an obsessive enthusiast willing to go through government paperwork for a range toy with little obvious utility.

Originally Posted by acrosome

If you want the accuracy at those ranges, you're simply going to need a long range rifle.

Yes, but what is the best performance I can get at 800-1,000 yards from a 14-inch barrel? And what chambering ought I be statting for that performance?

Look at it like this, I'm statting both the DMR carried by supersoldier marksmen that will be able to make very accurate shots at out to 1,200+ yards (maybe out to ca 1,500 yards) and the carbines that will have shorter effective ranges, but still outrange most weapons carried by human soldiers, because the 'typical' supersoldiers can still shoot more precisely offhand than most human snipers manage from a stable position.