The great .308 debate

AR/M4 Beyond 5.56/.223
1

UPDATE: I wound up building a 308 vs. buying what was listed below. If you want to skip to the final build, go to reply #77

I plan to buy one, and only one, .308/7.62. So I want to do it right, and be done with it. I have narrowed it down to the top 3 I keep seeing pop up on threads here: LMT MWS, LaRue PredatAR 7.62, FN SCAR. The KAC sr25 is excellent but too rich for me. The purpose of the rifle will be fun at the range (inside 300 yards) and EOTW SHTF battle rifle from hell self defense. I want a 16 inch barrel and something that will require little extra work to make me happy.

I have never shot any of these (only held a SCAR in my hands), so I will be relying on those of you that have (hopefully shot all 3) for your opinions/rankings in the following areas:

1 - Weight - This is important and it hurts the LMT the most, as I believe it is at least a couple pounds heavier based on other threads I have read. Thought the weight I’m sure helps with recoil. This is another reason I’m considering the PredatAR and not the OBR, as I want a lighter rifle.

2 - Trigger - I’m told the SCAR trigger would need to be replaced. Thoughts on whether the LMT or Larue have a better trigger out of the box? I just put a SSA on my 6920 and absolutely love it.

3 - Parts/furniture flexibility - Seems the 308s have more proprietary parts based on some of your posts. Which of the 3 has the most options to customize? At some point I may want to put on a keymod rail, have more choices for mags, change the stock, extra BCG, etc…

4 - Recoil - Which has the least recoil or can be easily configured to reduce recoil?

5 - Accuracy/barrel - I assume you’d rank, LaRue, LMT, and SCAR in that order? Any thoughts on barrel life between the three?

The PredatAR 7.62 is probably the closest to what I want out of the box but I’m seeing wait times over a year for one of those bad boys. I’m betting some of you liked it a little better but weren’t willing to wait and bought an LMT or SCAR?

Anyways chime in with your thoughts and let me know what I should be asking/thinking that I may have missed.

2

I don’t have a lot of experience with AR .308s, but I do with the PredatAR. Like the HK G3, it uses a fluted chamber to improve ejection. Unlike the delayed roller blow-back on the G3, the AR DI action does NOT need a fluted chamber. As a result, both rifles are hard on brass, making for minimal reloading capability for the brass. I would say that the PredatAR is actually harder on brass than the G3. The fluting reduces friction for the case wall, which is fine when you are ejecting, but bad for the brass during ignition. The brass swells into the flutes, and since there is reduced friction on the chamber wall, the brass case head slams into the bolt face harder than a typical AR-10. The case head will actually flow into the ejector hole shearing off bits of case head during ejection. It’s a good rifle otherwise, but very hard on brass. I’ve reloaded brass on M14s over a dozen times, but with a G3 or PredatAR I would probably only get a couple of reloads in.

3

Consider building one. Your criteria sounds a lot like mine. In the end I determined that nothing met my criteria and budget. Rainier Arms is a great place to start. I got a few good deals via sales that were happening at the time. There is a lot of cool stuff coming out in the 308AR world right now.

4

Regarding your question #3. I would go with the SR25 (aka Gen 1 DPMS) pattern. Most of the serious manufacturers are using this profile and the majority of accessories are for these (including Pmags which work with both DPMS profiles).

5

S&W M&P10, while not on your list, seems to meet your criteria.

Very light. You can put a SSA on it. It’s as compatible with after market parts as you can get in this platform, besides the bolt. It’s surprisingly accurate for its price. And recoil can be worked on (muzzle break like the SCAR, swap on an adjustable gas block, heavier buffer, heavier spring, etc).

6

I have considered this but am a bit intimidated by how much I don’t know. I have never built a rifle and would need to find a gunsmith to be confident it is done right. If I have a first build it will be a 22.

I learned a lot from this thread but it also reinforced how much I have to learn:

https://www.m4carbine.net/showthread.php?154622-Best-308-AR-(-2000-budget)/page2

7

As regards your #1 - Weight. I have an LMT MWS and do not see its weight as an issue. (I’m 5’10" and 170 lbs and 67). If I were going to be shooting off hand then maybe a little heavy. If you hang a bipod on front then it is a little less balanced. Recoil is mild - I do not like recoil - shooting the LMT MWS is a pleasure. I also carried an M-14 and M14A1 in the military - maybe that is why the weight is not an issue for me.

8

How do you shoot it if it’s not off hand?

9

Off hand (standing and no support). http://www.riflesilhouette.com/instructions/techniques.html For some reason I find I’m more accurate using “support”.

10

From your list, I would pick the LaRue. The scar doesn’t use popular mags which is no go for shtf, and the other is heavy as you say. You might also consider the M&P10, as its cheaper and a lot easier to get than the LaRue. Then again DPMS has the new G2 rifles which are likely to change the AR10 field just as the gen1 DPMS did. I think there are already G2 free float rails, but I haven’t checked if they offer keymod yet. I chose to go with mlok personally.

11

I’m with TrackMagic as far as building an LR-308 setup, and leaning heavily on what Rainier Arms stocks to at least figure out approximate final cost. I’d also use taking an S&W M&P10 and adding parts to it as the benchmark for performance for cost, since that’s already really close to a solid general use one and is compatible with most aftermarket parts that should make sense (i.e. upgraded furniture as needed, a handguard that works adequately, Geissele SSA/G2S or SSA-E/G2S-E, etc.).

For my part I’m waiting to see if any bigger manufacturers step into the game with an LR-308 type setup (Noveske, BCM, DD), otherwise I’ll just start with an Aero Precision Receiver set, stuff it with DPMS G1 type parts, run a custom barrel and MI SS-KeyMod handguard, MagPul/KAC furniture and sights, run AXTS/BCM/BAD ambi parts and call it good.

12

The larue is the closest to what I want, thought it is the most expensive with a crazy wait time.

The m&p is a compelling value but it is 18 inch vs my preferred 16 inches and would take quite a bit of work to get it where I want it. By the time I drop in a keymod rail, trigger, new grip, stock, etc… I am probably close to 2k. If I am gonna spend that much, may as well save a little more and go with a higher end 308 from the get go or build it.

13

Let’s says hypothetically I decided to build, I would certainly need some guidance on building a lightweight battle ready 308 that was following the loose 308 standard kac/DPMS gen1(assuming I did not screw up that is the basic platform…might have butchered it and shown my ignorance). From another thread I read, I could do this:

https://www.rainierarms.com/?page=shop/detail&product_id=3459 For barrel

https://www.rainierarms.com/?page=shop/detail&product_id=3479. Mega upper/lower with keymod rail

https://www.rainierarms.com/?page=shop/detail&product_id=2270 BCG

Could I then go with:

http://tradingplacepawn.com/shop-online/by-brand/geissele/geissele-super-semi-automatic-ssa-trigger.html Trigger

For sights I assume magpul MBUS pro are solid. Running those on my 6920 and very happy with them.

That brings my cost to about 1750

And what about a stock? My preference would be magpul STR or something close to it. Not sure if STR would fit and if I would need mil spec or commerical spec?

What else am I missing and what are suggested quality parts for grip, receiver extension, gas block tube, misc. lower parts, etc…?

From what little I know of rifles the most important parts are barrel, BCG, and trigger. I do not want to skimp on those.

14

You might be able to cut back on the weight some more by going with an LR308 pattern receiver set and the Fortis Switch or MI SSK rail.

For the buffer system go with a VLTOR A5 receiver extension (6 or 7 position depending on the stock you get), milspec diameter stock, AR-10 action spring, and AR-15 H3 buffer.

The gas block and gas tube are the same as AR-15 parts. The LPK you get will need to be LR308 compatible (enlarged bolt catch and larger mag release).

15

EMOD stock is really undervalued as far as durable, heavy, effective units go, and they come for really cheap with an A5 setup - I’d certainly give that a try. Defeats some of the lightweight overall, but can help with balance. Otherwise, I’d just procrastinate and buy a used one - with the new BCM unit coming out, tons of people on this board are about to ‘discover’ they no longer want an otherwise perfectly good buttstock.

16

Limited experience with the LMT and none with the LaRue, but I love my SCAR 17S. Owned it for over three years, and it’s a better weapon than I have the skill or money to truly take advantage of. Accurate, reliable, light weight, with very little recoil, and the smoothest operating system I’ve ever seen. The trigger may not be the best, but it’s not nearly as bad as most people make it out to be. The biggest handicap the SCAR had was magazines, but the shortage of 17S/H mags seems to be over, and they’re easy to find on Midway or Brownells.

17

For my part, the worry is the WHY behind the S17 magazines being really available - it’s hard not to assume that FNH-USA isn’t selling as many of the complete weapons as they were hoping to. The aftermarket isn’t exactly throwing magazines at it, and things like the Mossberg MVP that also use the SR25/MWS/LR308 magwell ones are becoming fairly standard.

18

The “why” is pretty simple, production finally caught up with demand. The early, American made mags had problems, and the story goes that most got sent back when they didn’t meet FN’s standards. Coupled with reports of people getting some of these early, American made mags, and them not working or being rusty, this story makes sense. Once the first batches of good mags started reaching people in mid '12, the mag shortage pretty much came to an end. All of the ones I’ve purchased have been fine.

As for SR25 mags, there are more than a few aftermarket lowers for the SCAR designed to accept them. I’ve just never seen the reason. SCAR H mags work fine, and I actually like the little not-MagPul base pad on the mags.

19

I am going to follow this thread closely, it is relevant and similar to my decision making right now.

I recently purchased a stripped Aero Precision lower (figured I might as well get the critical and “ban-able”) part and I am taking my time researching which upper to go with.

I noticed that Ares Armor has a good deal running currently on their 308 upper (pre-buy for around $800), but I am not in a rush and want to get the most bang for my buck. Of course one of the greatest advantages of the AR system is it’s modularity so I can see myself having a few uppers that share a lower.

20

Like Alpha said, .mil required a lot of mags once FN caught up civvie market had a chance to eat. SCAR 17s still sells very well for a .308 and even if future lack of mags worried you, there are options for aftermarket lowers which is NOT the registered part of the rifle. FN will continue to back the SCAR platform for a long time to come, even if SOCOM ditched it, that would have little to no impact on the civilian side. FN is one of the oldest weapons manufacturers on the planet with plenty of government contracts (US and foreign) including many other countries running the SCAR (even poor African countries). FN also has a solid history of backing all their guns with not only warranty but parts availability. Bottom line if they support FS2000 & PS90 why would you be worried about the SCAR not being supported? I am amused by all the SCAR hatred.

OP keep in mind, any decent .308 will cost a minimum of $2,500… But then you have to factor in cost of purchasing mags, quality ammo which is pricey, good glass, suppressor, spare parts, other various accessories… Cost of the gun itself is only a fraction of the cost of ownership…: