2024 308 Carbine options?

**opngrnd** · 05-07-24, 08:34

It's 2024. I'm thinking about moving into the 308 world, and I'm curious on what the options are with the following criteria:

1- Reliability. Using precision standard loads that are magazine fed.
2- Handling. I'm not looking to build a DMR. Lighter is better, within context.
3- Accuracy. 2MOA with common match ammo, if possible.
4- Spare parts. Murphy and all.
5- Suppressor compatibility. This is negotiable, for now.
6-Price. I'd rather spend 2k than 4k, but I'll happily spend 4k on something that works.

The role is for increased performance on target out to 800 yards, and for use in the heavy class of 3gun comps. At this time, I leaning towards a 16" barrel. I don't want a gamer gun.

I've shot M1As, FALs, and SCAR-17s before, I liked them enough for what they were. The SCAR is a possibility, but I need to look at their issue with breaking optics. I've thought about building an Aero M5 with a Criterion barrel, but wonder if there are better ways to go.

What are the forums experiences and recommendations?

**opngrnd** · 05-07-24, 08:40

For reference, my current idea is to go with a Daniel Defense 16" 308.

**markm** · 05-07-24, 08:43

I really haven't shot an AR-10 I thought I loved, but if you don't have a weight constraint, the LMT MWS is a bomb proof rig. Suppressors on these guns make them much less enjoyable to shoot for me. When you add a can, you'll probably want to address the gas issue or it will be brutal.

**Alpha-17** · 05-07-24, 11:09

The claims of SCARs breaking optics is incredibly overrated. I first saw the claim with the 16S before 17S were on the market, but now you don't see the 16S claim being taken overly seriously. Mostly seems to be a combination of cheap optics, cheap mounts, and mounting them too far forward. (and those same issues will pop up with other .308 options like the AR-10)

I've had a Trijicon TA11E on my SCAR for over 12 years now without issue. Planning on swapping it out for a Sig Tango MSR 1-10x to see how I like it. We'll see how it holds up.

To answer your question, personally, I'd steer clear of anything DI if you want to run a can. (blasphemy for this site, I know) Adjustable systems certainly exist, but DI seems to be waning now. The SCAR 17S would certainly seem to fit the bill, so I'd definitely recommend it. FN doesn't like folks running a can on them, but the end users seem to make them work without issue. Depending on how you feel about bullpups, the Tavor 7 might be an option.

Finally, and this is certainly the most expensive option, would be a Sig Spear in .308. High price, but seems good to go out of the box, and fits most of your requirements. The Spear is heavier than the SCAR, but mags are lighter, and much, much cheaper and more available. Spare parts and aftermarket support will only increase in coming years. If Sig follows through with caliber conversion kits, being able to easily swap between .308, 6.5 CM, and .277 Fury/6.8x51 might be a good bit of future proofing. I'm strongly considering the Spear myself, for those reasons.

**Defaultmp3** · 05-07-24, 11:34

Originally Posted by Alpha-17

The claims of SCARs breaking optics is incredibly overrated. I first saw the claim with the 16S before 17S were on the market, but now you don't see the 16S claim being taken overly seriously. Mostly seems to be a combination of cheap optics, cheap mounts, and mounting them too far forward. (and those same issues will pop up with other .308 options like the AR-10)

A USASOC tester I know of has publicly stated that the SCAR-L was harder on electro-optics than the SCAR-H:

Its not the [SCAR heavy] that has the issue...its the SCAR-L. The recoil impulse in the SCAR-L is very sharp under accelerometers and creates a high G stop on deceleration. It doesn't effect the erectors on magnified optics as much as it effects the FPA, A spheres and circuit boards of laser aiming systems and RDS...

...

Not to be a bummer here, but the fact is that the SCAR-L does have recoil impulse issues. Those are well documented by some heavy hitting engineers on the government side. That being said, the SCAR-H shouldn't be lumped into that group. Although the SCAR-H has other issues that precluded its wide distribution in SOCOM as a Service rifle, it's still a good rifle.

...

the Army (USASOC) is the one who ID'ed the issue. I'm not sure what you're talking about reference civilian issue. I can reference government tests and govern enemy reports from NSWC-C and ATEC. I have the government results from evals and personally seen the recoil profiles and can attest the MK16 is far more sharper on the G Force side than the MK17. If you have a .mil address I can forward you these evals...

...

NECESSARY DISCLAIMER: IM NOT AND ENGINEER. I'm just a Combat Developer/User. But I am semi intelligent and have been doing this for almost 35 years...It is about bolt speed combined with the excessive mass of the MK16 bolt as it relates to chamber pressure and the pressure curve. As it was explained to me by the evaluation engineer, the numbers reflect that the chamber pressure of the 5.56 caliber Wylie chamber de-obdurates at twice the speed of a standard SAAMI spec 7.62x51mm chamber. Although they both pop at about the same pressure - give or take a couple or three thousand PSI - the .308 chamber allows for a slower unlock speed/de-obturation which translates into a much slower g force transfer to the outer surface of the 7.62 weapon system. This is my simpleton way of explaining that although the bolt mass of the MK17 is far greater and therefore it would logically point to this being an issue, the counter-intuitiveness of the issue betrays logic.

I would also note that there are a variety of optics and MFALs that had to get Crane approval before they were considered CAR-hardened; the SCAR was the reason to create the LA-5D/E, after all, and they remain a benchmark for military-grade thermal and I2 clip-ons.

Originally Posted by Alpha-17

To answer your question, personally, I'd steer clear of anything DI if you want to run a can. (blasphemy for this site, I know) Adjustable systems certainly exist, but DI seems to be waning now. The SCAR 17S would certainly seem to fit the bill, so I'd definitely recommend it. FN doesn't like folks running a can on them, but the end users seem to make them work without issue. Depending on how you feel about bullpups, the Tavor 7 might be an option.

Finally, and this is certainly the most expensive option, would be a Sig Spear in .308. High price, but seems good to go out of the box, and fits most of your requirements. The Spear is heavier than the SCAR, but mags are lighter, and much, much cheaper and more available. Spare parts and aftermarket support will only increase in coming years. If Sig follows through with caliber conversion kits, being able to easily swap between .308, 6.5 CM, and .277 Fury/6.8x51 might be a good bit of future proofing. I'm strongly considering the Spear myself, for those reasons.

I would say that it would depend on the can, particularly with the low backpressure options coming onto the market. My SR-25 is certainly rather gassy using the factory RE spring and buffer, with my SOCOM762-RC, but it's quite tolerable. I'd also note that the Daniel Defense comes with an AGB from the factory.

If lightweight is the goal, and you're not adverse to tinkering, the Ruger SFAR could be an option; accuracy is somewhat inconsistent, it seems (I've heard accounts of both real tackdrivers and some mediocre ones), but it's hard to beat a small-frame AR for handiness. If suppressing, throwing on a RifleSpeed AGB is totally an option. Otherwise, I would probably stick with a KAC, Daniel Defense, and maybe the Colt, if you want factory support in the AR platform (LMT being a bit on the heavier side, although it can be brought down to under 9 lb with the right barrel and upper receiver; their current QA/QC woes are also a bit off-putting).

Outside of that, the SCAR 17S remains somewhat intriguing, as does the SPEAR, though I question the long-term viability of the SPEAR, given that SIG is prone to doing rolling changes on their platforms. The BREN 2 BR seems like it's unlikely to come over any time soon. The B&T APC308 might be also worth looking into. The H&K MR308 is probably too heavy for what you're looking for. The DT WLVRN remains an unknown, though with DT's current track record with the MDR, I would be quite leery, even without taking into account the wonkiness of a bullpup.

I'll also note that instead of .308 Win, Failure2Stop has argued for the 16" 6.5 CM instead: I [Failure2Stop] can do more outside of pistol range with a 16" 6.5 Creedmoor rifle than just about any other rifle/caliber combination on applicable targets out to 1k.

**opngrnd** · 05-07-24, 12:34

I appreciate the replies. I'm not opposed to switching the caliber to 6.5 Creedmoor, but I figure it adds another level of nuances that I haven't studied. I do run 6.5 Creedmoor in bolt gun. Ultimately, I'm hoping for a package that runs off the shelf ammo well.

**markm** · 05-07-24, 14:21

Originally Posted by Alpha-17

The claims of SCARs breaking optics is incredibly overrated.

Even if the SCAR doesn't break optics, it's by far the most miserable 308 gasser I've shot. The SCAR light isn't too bad, but the H is pure snappy recoil hell.

And you know if it's a SCAR gay, there's a suppressor on it to make it even worse.

**JediGuy** · 05-08-24, 05:20

A pencil-ish weight 308 barrel is a beautiful thing. After building an aero M5 receiver set around a Brownells (Faxon) 20” retro pencil barrel and Troy carbon fiber handguard, the darn thing was easier to flick around than a poorly designed 16” 5.56 barrel.

But finding parts like that are impossible now without spending a ton of money, as far as I can tell.

Two options I would consider:

1) Ruger SFAR - Seems inconsistent and typically overgassed. But a hybrid frame that can use standard AR free float handguards. If they got this right, it seems like a great choice. If. And it’s cheap.

2) Colt M7 - Because it’s Colt. They are on sale for $2200, and also “hybrid.”

**sidewaysil80** · 05-08-24, 07:19

Originally Posted by opngrnd

It's 2024. I'm thinking about moving into the 308 world, and I'm curious on what the options are with the following criteria:

1- Reliability. Using precision standard loads that are magazine fed.
2- Handling. I'm not looking to build a DMR. Lighter is better, within context.
3- Accuracy. 2MOA with common match ammo, if possible.
4- Spare parts. Murphy and all.
5- Suppressor compatibility. This is negotiable, for now.
6-Price. I'd rather spend 2k than 4k, but I'll happily spend 4k on something that works.

The role is for increased performance on target out to 800 yards, and for use in the heavy class of 3gun comps. At this time, I leaning towards a 16" barrel. I don't want a gamer gun.

I've shot M1As, FALs, and SCAR-17s before, I liked them enough for what they were. The SCAR is a possibility, but I need to look at their issue with breaking optics. I've thought about building an Aero M5 with a Criterion barrel, but wonder if there are better ways to go.

What are the forums experiences and recommendations?

I have to be honest, building is better. I’m NOT the guy to always recommend building your own…but in the case of .308 gas guns…I think it presents a superior (to most) product and much much better value.

Starting off with a semi-monolithic or monolithic upper receiver will truly isolate the barrel nut and in a sense truly free float the barrel. The argument could be made that any input on the hand guard is minor or incidental, but then again the gold standard for semi-auto accuracy (imo LaRue OBR) uses that feature and they outshine their competitors in that regard. More importantly, precision is all about consistency and repeatability, truly free floating the barrel nut does just that and removes a potential variable.

Next up is truing the receiver face. This ensures the shoulder of barrel extension sits mechanically flush to the receiver face. If not, and barrel nut is torqued, it will hide the mask and create a tension point on the barrel extension that, during recoil, will induce some flex or influence on consistence.

Lastly, use of shim stock or Loctite Slip-Fit to “bed” the barrel extension. This ensures a tight, 100% contact, fit of the barrel extension to the receiver.

The above are imo the ways to maximize accuracy out of the AR-10 platform. Assuming a worthy or high quality barrel is used, following those guidelines will produce at least a 1moa gun if shooter does their part and other industry/tdp specs were followed.

Now the inconvenient truth with large frame AR’s is they’re always over-gassed. An adjustable gas block is mandatory and another trick is to opt for a 16” rifle length barrel. I suspect that the shorter length of dwell time reduces how long the system is pressurized and it results in a softer, more manageable recoil impulse when paired with proper buffer system and adj. gas block. You can hit your desired distance goals with 16” .308.

Lastly the buffer. I believe a vltor A5 or ar-10 specific buffer tube paired with standard ar15 H3 carbine produces the softest recoil impulse. Combined with aforementioned barrel setup and it is a noticeably NOTICEABLY softer recoil then SR-25, OBR, and a myriad of other production guns I’ve shoot back to back.

I know I’m a random guy on the internet but literally a half dozen of my shooting friends from precision matches have had me help them build rifles to the above standards as they were floored by the difference in recoil/“shootability” (aka being able to spot your own splash at higher mag without recoil interference) compared to the litany of production guns we have all owned/used. I set the gas block for optimal performance unsuppressed as most of my shooting prefers the muzzle brake for performance. However even with a can I’ve had no issues (albeit a tad gassy when attached). This setup/platform has served me well in various climates/weather situations with no need to readjust gas block unless dialing for new load.

Finally there is cost. The above setup with Criterion barrel is around $1300-$1500 depending on sale shopping/pricing.

Sorry for the long read, hope it helps.

Ps. Skip piston, especially for precision. Remember that whole repeatability and consistency thing for accuracy? Having a reciprocating rod attached to your barrel completely negates that concept. Furthermore it makes an already front heavy platform more front heavy.