Thinking of building a .308 AR platform rifle....

[nickdrak]

Now that there seems to be a good amount of options available for .308 AR parts (.308 BCG's, barrels, receivers, handguards, etc.) I am considering building up a "Precision" .308 AR from parts. Trust me, I would love to be able to drop $2500-$5000 in one lump sum on a LaRue OBR, LMT MWS, SR25, etc., but that just is not in the cards.

I am curious if anyone around here has built one up from parts, and if it has been reliable. As far as receivers go, what are the best available options out there? Iron Ridge receivers? Mega?

The Rainier Arms match barrels look really nice.

What bolt carrier groups are available aside from DPMS. Are the JP complete BCG's good? Can an LMT .308 BCG be sourced?

Im not looking to buy a complete DPMS or Bushy .308 rifle and then add to it. I want to start from scratch with premium parts and build it up over the next year.

Thanks in advance!

Stay safe,
Nick

[TAZ]

In the very same boat as you. Just can't drop that kind of cash up front. Not sure on the BCG from LMT being available, but so far in my preliminary search I have found Rainier, Fulton Armory, DPMS bolts and carriers available. Not sure if they are all rebranded DPMS parts or other sources though.

As for receivers I am 90%+ sure that I am going to go with Mega Monolithic Ma-Ten. Based on the price point Mega suggested, it will be cheaper than a hand-guard+receiver purchase. Plus you get a matched set. May end up on the heavy side, but such is life I guess Still haven't yet gotten myself set on the other parts though. Rainier barrels look good and are priced well. From my limited understanding they use Shilen UltraMatch blanks and add their own contour. I think for the price they are the leading contender unless you're willing to plunk down cash for a Noveske or have Kreiger turn you one that matches your supplied bolt. It's going to be an interesting few months for sure.

I'm hoping to be able to assemble an 18" mid length system at the end of the cycle. Just in the process of procuring the tools for the 308 job and then I'll start with the parts and pieces as funds become available.

[caelumatra]

Same boat, just a few steps ahead. I've got a MA Ten I'm building. I was looking at IRA before I saw the Mega and IRA is way more expensive.
You can find matched MA ten upper lower sets for $500 when matched IRA are $1075 and the mega comes with a charging handle, take down and pivot pins and ejection port cover all installed. I know those aren't expensive, but its nice not to have to buy them considering in an AR10 LPK, the only different parts are the take down and pivot pins and the bolt catch.

I bought mine right before Christmas but at shot, mega showed off a monolithic upper for the MA-ten so if that interests you, hold off a bit.
http://www.youtube.com/watch?v=NUzWIupk1Lo
There was another company at shot that has ambi lowers. I think its AXTX but I cant remember.

Right now for rails DD has a lot that are available. SWS has some as well. Rainier has a set. Troy has the TRX extreme which is probably the cheapest and lightest @ $200.

Fulton Armory sells bolts. Armalite, DPMS and probably a few more. They're all in the same price range, +$250ish.

As for stocks, I'm having sort of a difficult time finding solid answers on this one. I dont want to buy Slash's $100 buffer just to use a carbine stock. There MUST be another option to get a carbine stock :(

Tons of folks make barrels. Fultons are Kreiger, Rainiers are Shillen, Noveskes are...cant recall
I just looked on the fulton site again and cant find where it said the barrels were kreiger, but I know for sure it did say that at one time

I've got a DD LPK installed but because I dont have a bolt yet I dont know if the bolt catch works properly yet. The mag raises it up properly so it should work, but I dont know for a fact as of this moment. Right now I have a PRS and may stick with it, but its pretty damn heavy and I'm just done with the lower half, but after seeing the RISR I may go with that on an MOE stock to save some weight. I'll be going with the TRX rail as well to save weight and getting the barrel dimpled from Marvin as soon as I get it. I'm ordering a Noveske 18 as soon as I can find one in stock. But because they are armalite pattern I'm forced to go armalite on my bolt because I dont think any other major mfg make any of their pattern. DPMS pattern seems to be the patter most used


I know this post is sort of rambly, but since there is no cut and dry, this works and this doesn't for ar308, its all been learning for me.

There are a lot of threads on TOS on the ma ten
[url]http://www.ar15.com/forums/topic.html?b=3&f=121&t=516132[/ur l]
[url]http://www.ar15.com/forums/topic.html?b=3&f=121&t=515222&page=1[/ur l]
[url]http://www.ar15.com/forums/topic.html?b=3&f=121&t=413443[/ur l]
[url]http://www.ar15.com/forums/topic.html?b=3&f=121&t=517454[/ur l]
[url]http://www.ar15.com/forums/topic.html?b=3&f=121&t=512370[/ur l]

I dont post there, but in googling, thats what comes up and those I've had bookmarked for a while in browser now for good references.

There is a user here (and there) who modified a MOE midlength to fit on a 16" 308, but since you're going precision route, as I am, it doesnt seem relevant to go non free float.

[Anchor Zero Six]

Vltor is now offering a AR-10 type Car buffer tube. Just need to use the Armalight AR-10 Car buffer and spring. I guess you could also just get their buffer tube but IMO not as nice as the Vltor.

These are a bit longer than the 5.56 versions just like the LMT and KAC buffer tubes.

[caelumatra]

Good deal. Now just to offload my PRS to someone

[nickdrak]

I was looking at this complete BCG from JP: http://www.jprifles.com/buy.php?item=JPBC-4BA
It's expensive, but if it works reliably it is worth it in my opinion.

I would never buy a BCG made by DPMS for any of my 5.56 AR's, so I definitely won't buy a DPMS BCG for a .308.

[evileyeswatchin]

Was in the same boat as you.
Went w/Mega upper/lower and a Noveske bbl, Armalite bcg.
Will let ya know how it shoots next week.

http://i104.photobucket.com/albums/m169/evileyeswatchin/015.jpg

http://i104.photobucket.com/albums/m169/evileyeswatchin/022.jpg

[TAZ]

Stupid question, but do you have to have a 308 specific buffer tube?? Was hoping to recycle the UBR off my SPR clone. Was I smoking crack when I read that the tubes went either way.

ETA: Answered my own question via google. Slash buffer and spring allows for AR15 tube use.

[Mute]

I just built one up with a Mega Ma-Ten set and on the first range trip it functioned without a hitch (roughly 80 rounds through it). Haven't had a second trip yet. I built mine with a Ranier Arms rifle length Ultra Match barrel with an Armalite extension and BCG. I don't know about DPMS, but Armalite has a proprietary length gas tube. If you build with an Armalite bolt, you'll need their gas tube both for rifle and carbine length. I'm pretty sure you can use any bolt as long as specs are close to that of an Armalite or DPMS and you have a matching barrel extension.

As for buffer tubes, you can use standard buffers tubes, but for carbine length, you'll need a slash buffer and spring to do so.

I just finished sighting in my scope so I don't have any groups yet, but it looks to be at the very least, 1 MOA capable if not less.

[Anchor Zero Six]

You have a weight on this as it sits here?

http://i104.photobucket.com/albums/m169/evileyeswatchin/022.jpg[/

[Mute]

One quick note. Mega is about ready to start delivering Ma-Tens in a monolithic platform. You might want to wait and see.

[nickdrak]

I will probably get the Mega standard matched upper/lower along with the Troy TRX rail to save some weight.

[nickdrak]

Well, just to give myself an idea of what I am looking at, I came up with a tentative list of parts to complete this build (minus optics & mount). For right around *$2800 (*LE discounted prices on most items listed) here is what I came up with:

*Mega MA-10 matched upper & lower
*Rainier Arms UltraMatch 18" barrel
*JP Enterprises JPBC-4 .308 BCG
*Troy Industries TRX-308 13.8" rail
*Geissele SSA-E trigger
*G&R LPK (NO trigger) and DPMS bolt catch
*LaRue gas block
*KAC MicroFlip front sight
*Troy flip-up rear sight
*Gas tube
*BCM 7.62 GunFighter CH
*MagPul MIAD grip
*MagPul PRS stock
*Surefire MB762-211C muzzle brake

[TAZ]

Looks like you and I are heading down a very similar path. Haven't put my shopping list together yet, but your final tally of $2800 is a bit disappointing, especially if that includes discounted pricing. I may end up doing it just for the sake of having done a complete build and not to save $$.

[caelumatra]

I'm sure you've considered this Nick, but the PRS is heavy. Awful heavy. My complete lower with an empty upper weighs over 5 pounds

[Mute]

His pricing is about what to expect considering the components. Most of it is not cheap stuff. The CH is nice, but I personally don't think is needed. The one included with the Ma-Ten is plenty stout. That will save you a few bucks. Also you might find the PRS not the best match for your setup as much of your weight may be toward the stock due to the shorter 18" barrel and very light Troy rail/handguard. A Magpul ACS or even CTR might give a more neutral balance. Other than that it sounds like a bang up build.

[nickdrak]

The weight distribution is something I hadn't considered. This is going to be a precision rifle so the overall weight of the finished product is not a big concern. Is the weight distribution/balance a major consideration on a precision rig that will be shot from a bipod most of the time?

The reason I choose the Troy TRX-308 rail was simply to save some money, not weight. I may get the PRI rifle length tube instead of the Troy which will drive the cost up about $140.

[Anchor Zero Six]

PRI is lighter and looks alot better...think MK12 MOD 0 in 308 :)

[Mute]

Weight distribution is a matter of personal preference. I like an even balance to maybe a slight muzzle heavy balance for a precision rig because it helps to steady the movement at the muzzle. YMMV.

[Mute]

Here's an added consideration. If cost is your primary reason for the Troy, the monolith MA-Ten is supposed to be about $100-110 more than the non monolith MA-Ten. If you wait for the mono version, you'll save some cash, possibly some weight and have a stiffer, sturdier handguard.

[evileyeswatchin]

You have a weight on this as it sits here?

http://i104.photobucket.com/albums/m169/evileyeswatchin/022.jpg[/

9lbs 14oz. according to my scale.

[armakraut]

Wait for the Colt SP901, or buy an LMT.

[Anchor Zero Six]

Damn I'm at 9.2 on my LMT w/o optics after cutting back to 13.5 and swapping the ACS to a CTR.

Like the build and the weight alot, good job!