After many years of puttering around with 5.56 Ar's I'm thinking of getting into the 308's. There are a lot of posts and threads about reliability problems. I really don't want to play around with reliability problems if I can avoid it.
And, I'll be looking at an entry level rifle, not a Knight or Larue, etc.
Any advice from you all who are experienced in this area?

A local dealer who has a good many high and low dollar rifles recommended getting started with a Bushmaster MOE which he said has been more accurate and reliable than many others.

Thanks for any help.

Smith & Wesson M&P10

I'd go with the Ruger 762. Glenn Zediker is a High Power guru of note, he's opined that MANY have tried to use AR10's for that COF and they broke a lot. I think the piston may actually be accomplishing something with that rifle, unlike a 5.56 AR

Thanks. There are things-details about each that I like.

After the addition of an adjustable gas block my DPMS LR308 gen II has been completely reliable, accurate, and easy on the brass. I have a 24" heavy barreled LR308.

The geissele high speed NM trigger and syrac ord adjustable gas block where mandatory upgrades.

Was that Gen II overgassed like JimmyP's.

Reliable Accurate Affordable

Pick two.

I had an MP10, works 1.5 - 2 MOA gun call smith ask them what you should expect. DPMS Gen 2 Hunter, not even one box of shells thru it, sent it back they returned my money, could have just been that one gun, lots of people like em ask rickiD how his is working, Ruger 762, heavy, must replace the trigger, shoots 1MOA or better, works.

Thanks for the posts.

Build your own and you can make it reliable as you need.

I looked into that. Have built AR's as needed/wanted since the mid 1970's and there were specs on parts.

Looking at the 308 I could just see dropping cash on expensive parts that weren't compatible so put the idea of building on the back burner.

Do some research. The only thing different is the upper and lowers. You have the Armalite and DPMS designs. Lots of help at the fire.

I have been having really good luck with my CORE 30 LR TAC. Runs about 1/2 moa with hunting bullets and a touch better with match bullets. Comes ready to go with hard case and PMags. Plus CORE has a no BS life time warranty and is ran buy good people.

if you can stomach a gun that with 20 round magazine (full up), 24 ounces of scope/mount, plus sling with a full up weight of about 11 pounds plus the cost of a replacement trigger, your good to go with the Ruger. I am happy/surprised at how well it shoots, being a piston gun and all. Turns out I am also kind of keen on the piston design in the thing, its function is real positive, kind of AK'ish.

+1

Yes, if you understand what makes them work. They are not AR-15's and way too many people, manufacturers included, cannot grasp that.

This one runs like a Kenyan.

M00_3761 by wareagle700, on Flickr

What kind of brass life are y'all getting with the 308's?

Same brass life as my bolt guns. It really depends on how hot you are loading.

That's a very nice looking rifle you have there. Would you mind sharing some specs, particularly the barrel?

Thanks, part list below:

MEGA 308 receivers
17" Lilja barrel (rifle length gas) I had it cut back from 20".
SLR Sentry gas block
SLR handguard
JP LMOS (bolt carrier group)
JP Silent Captured Spring (recoil spring/buffer)
Geissele SSA-E trigger
SlencerCo Specwar brake
Nightforce scope and mount
KAC 45 degree irons

Thanks, I may be looking back at this thread when making a parts list..

Yes, thanks.

Its my understanding that almost all the Gen IIs are over gassed. I was having problems and damaged brass before the addition of the syrac ord. adjustable gas block. I really like the syrac gas block because it has a ball detent on the adjustent screw and is less likely to come out of adjustment. After a very simple adjustment I now have my DPMS gen II running like a top and brass is undamaged after firing. It still flings them out a few feet but not the half mile it used to.

I�m pretty impressed with my gen II. If they had uppers available for it I would build a second one in 6.5 creedmoor, or maybe a fast twist 243.

several on here mentioned the adjustable gas block to me on the Gen2 hunter, my concern was that on my gun the issue was ejector damage and not extractor damage. It put all the brass in a neat pile at about 3:30 or 4 but some of it was bad torn up with twin holes bored into the back of the case and a half moon bend between them.

This one shoots fine "out of the box" even with the crappy Ruger trigger. My first outing with it is below. The top hole in bottom target is before I cranked my elevation down shooting 150 BTSP's over varget, the second 3 shot group is WW 150 powerpoints. I have repeated this a few times now and the gun is consistent, these are not "best" hand picked groups. It sucks that it weights almost 11 pounds full up and 20 rounds.

The Ruger is definitey one of the more attractive options for .308's under $2,000. POF is another piston dirven .308 that is capable of very good accuracy around the $2K range. The one's I've shot would shoot MOA with match ammo. I wouldn't hesistate to use either one.

@Josh Sorrenson - An adjustable gas block will solve most cycle of operation issues on a large frame AR rifle. Having experimented with just about all of them, the Syrac Ordnance Gen II is the clear standout.

@jimmyp - Do you have Gen II DPMS that's damaging your brass? If this is the case, you'll want to install a heavier buffer.

I thought the same thing before I got the SLR.

Really... What feature or operational capability of the SLR puts it ahead of the Syrac?

My apologies, I noticed the Gen II part after I posted. My experience was with the Syrac Gen I which was a bit tedious to adjust and would freeze up as carbon built up. The clamp on version was also a bit big and would only fit under a few handguards. The Gen II may have resolved all those issues. If so, I am sure it ranks right up there with the SLR.

Is that recoil spring/buffer considered heavy, (for a buffer?)

I put an 18" barrel on my DPMS and tuning the new adjustable gas block has not been as successful as I thought it would be.

Jimmy;

Any negative reaction to the 16" barrel?

No, it is made to work with the JP lightweight bolt carrier group. What problems are you having with tuning the gas block?

I have an adjustable gas block made "in house" by precision firearms in WV.

Trying to find the sweet spot seems impossible. Cannot tune it so the brass does not slam the deflector and get that crease in it every time. I glued the velcro doodad like y'all suggested. Next step I guess is a heavy buffer and just slow it all down. Or swap gas block.

Whose gas block are you using? There are really only two gas blocks on the market that are nearly linear when it comes to metering gas. They are the Syrac and SLR.

These folks are real nice people; he made the gas block but I don't see it on his web-page:
http://www.precisionfirearms.com/43.html

I had a suspicion that it was something along the lines of what you are saying about being "nearly-linear"

I had an instinctive thought that metering the gas was not as simple as might be thought.

Just checked out the SLR website. VERY good prices on everything.

Thanks y'all; I had never heard of SLR before.

What makes these 2 gas blocks so much better than any of the other adjustable gas blocks on the market??? I am running a Wilson adjustable block and it has worked great.

http://shopwilsoncombat.com/Adjusta...-Straight-Gas-Tube/productinfo/TR-AGB-C/

No, it's loud but I wear pro ears gold when I shoot it.

They have locking detents so screws can't back out or loosen yet they adjust with just one wrench like the others.

The photo below shows three metering screws. Syrac Ordnance on the left, SLR in the middle and JP on the right.

The JP is just an off the shelf cup tip set screw. The threaded body of the screw simply can't meter gas as effectively. When tuning a JP style block, you start with screw closed and back it out until the rifle completes a cycle of operation. These style gas blocks are either on or off given a specific cartridge. Once you hit the adjustment sweet spot, moving the screw in or out changes nothing (non-linear). I have no idea what type of screw the Wilson variant uses but I wouldn't be surprised if it were the same as a JP.

The Syrac and SLR variants work better because they have a machined metering surface. The metering screw on these models are precise enough that you can walk the ejection pattern through about 90 degrees. I'm prefer the Syrac varaint over the SLR for a few reasons:

1. The Syrac screw is purpose built whereas the SLR screw is just a turned down set screw.

2. The Syrac screw has four metering detents compared to the SLR which has three. This allows for more precise metering.

3. I'm not fond of the SLR leaf spring retention for the detent ball. It may be subjective but it's more likely to fail than the Syrac.

[quote=jimmyp]....

.... I have repeated this a few times now and the gun is consistent, these are not "best" hand picked groups. It sucks that it weights almost 11 pounds full up and 20 rounds.


It's unloaded weight is reported to be 8.6 lbs. The DPMS G2 AP4 is a little over a pound lighter per manufacturer's specs.

I wonder how light you can expect to go for a loaded 308 AR.

The Wilson...

http://www.wilsoncombat.com/press/Wilson%20Combat%20Adjustable%20gas%20block%20instructions.pdf

I am not sure how moving the JP screw in or out would not change anything. If it is closed and then opened until it cycles which would be the sweet spot then how come turning it in or out from there isn't going to change anything. So if you use the JP and find the sweet spot for a certain round but then you changed the to a different round your saying you can't reset the JP block.

The only thing I see that the SLR & Syrac has that the other don't is the dent adjustment which would limit the adjustment to the dent spots.

Does the unthreaded portion of the Wilson screw seal off the gas instead of the threads?

If I'm understanding correctly, the Syrac and SLR use the unthreaded "stem" portions on the end of their set screws to more effectively shut off gas in addition to the detent feature, which would limit you to 1/4 or 1/3 turn adjustments but would also allow some repeatability as you could count clicks.

I have a cheaper gas block on my 260, and I don't like it. The simple set screw moves too easily, and I was told to use rtv silicone to seal and "set" the screw by the person that sold it to me. I will be changing it out at some point..

Exactly...

It looks like the Wilson works the same as the SLR and Syrac as far as metering gas. That being said, the jam nut and straight gas tube are deal breakers for me.

a pound of rifle seems like a lot to me these days...

Enlighten me on the problems of a straight gas tube.

There's nothing wrong with it at all functionally. It's just another non-standard part I don't want to deal with.

I'm with you on that!

What type of failure is the leaf spring detent more prone to? Have an example?

I'm not sure exactly what material the leaf spring is made from but it rusted overnight after being exposed to a little salt spray. I tend to approach my appraisal of parts from a hard use, worst case scenario standpoint. Again, I'm not bashing the SLR. I own two Sentry 9's which are installed on bull barrel builds but only because Syrac doesn't make 0.936 variant.

Non Standard....Wasn't we talking about he AR10/LR308. There isn't anything standard that I am aware of. The straight tube is standard on mine.

You got me... The large frame platform hasn't been standardized for sure.

http://www.brownells.com/rifle-part...8-ar-chrome-lined-barrels-prod80214.aspx

This Criterion hybrid contour lists at 2.6 pounds.

Anybody have any idea what the S&W 18" barrel weighs? The S&W balances nicely in the hand. I think it is a pencil barrel.


Faxon:
http://faxonfirearms.com/18-medium-tapered-308-win-mid-length-4150-qpq/

Faxon is 2.28 lbs

Anything out there lighter and available?

LMT is another solid AR10. I have had no issues with mine and you can swap barrels easy.

Robert, for the last couple years Faxon seems to be one of the leaders in making real light AR barrels. They are probably your best bet right now.

I handled a Daniel Defense .308 this past weekend. Not crazy about 16" barrel .308's but it seemed relatively light & handy. Spendy, too. They also have a Ambush cammo model which has a 18" barrel. 8.6 lbs with 18" barrel.

I expect it will be very reliable, how accurate it will be is a different question.

I have a DPMS Gen 2 Hunter. I wanted a relatively light weight 308 with a 20" barrel. That describes the Hunter.

I had the same issues, maybe not as severe, as Jimmy describes, but hoping for success in this package, I let them work on it. Twice. They got it right the second time, and I question if they even did anything the first as they were changing repair stations from internal to external. A good move on their part.

Mine shoots about a inch for 5 and it's a semi-auto hunting rifle. I'm good with that.

I wouldn't suggest you might not have problems with one, but I would believe they would make it right. I'm glad I stuck it out and have it in my inventory.

I have a Rock River 308 varmint. It's very accurate. No problems with it. I shoot a 150 Sierra GameKing with 44 grains of H4895. Lake City brass.

My DPMS Gen1 has rocked through three classes at thunder ranch Oregon (just finished a class Saturday). 600-750 rounds over 2.5 days each time.
Wore out the bolt @ 4400 rounds. Had a JP FMOS bolt and BCG installed before this class. Round count is over 5,500 now. Gonna need a barrel soon.
Remember the acronym MMA--magazines, maintenance, ammo

I've been very pleased with my FNAR--I know its looked at as kind of a beast but my oh my does it perform--its just that the mags are so expensive--it really is rock solid when shot from a rest--- shooting freehand is a bit of a challenge for me at my age

tex, how spendy was spendy?

I have the Colt LE901-16S in .308 and have had no issues. It's just heavy, but shoots great.

$2499, IIRC

Thanks, tex. Nice rifles. That DD5 18" Ambush in Kryptek Highlander is a beauty. Cheapest I found was $2699.

Buy one and tell us how it shoots

Plumbing and ac repairs at several rentals have cured my gun $$ for this month.

I recently got a Windham Weaponry AR-10 and so far it has functioned well. It has swallowed 147gr FMJs and 180gr Remington Core-Locks without a hiccup and I have done a ladder with 42-47grs of TAC pushing a 150 Hornady Interlock as well. Disassembled the bolt and cleaned it once so far. Throws all brass to 1-2 o'clock but doesn't damage it. So far I'm happy.