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Lightweight 2A Arms Xanthos 6.5 CM Build

I am assuming you mean the Tennessee Arms polymer lower. Got another polymer lower, last one was 6.25 ounces, got this one down to 5.95 ounces. This cuts 0.30 ounces. This is my first polymer lower at 11.80 ounces. I need to weigh this #2, should be 11.50 ounces.
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Found it, @ 11.30 ounces as I did further trimming on the polymer and removed the castle nut.
TennLower11.3oz.jpg
 
This 308 pencil barrel does great with 110 grain, loves the 110 Varmageddon. Actually looking at getting a lighter CF buttstock that is longer than the present one. I even cut the titanium grip screw 1/4 inch to 1.5 inches length.
Varm110gr.jpg
 

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Yes, I got the lower name wrong in my last post. Thanks for sharing that, that’s amazing! My builds are on Xanthos uppers/lower sets, I had no idea I could shave additional weight with a polymer lower. And 2A Arms now lists the Xanthos uppers for sale separately, they use to only be available as a set. Might have to grab another one and build a 375 Raptor or 338 Federal.
 
Btw, is that a Form 3 grip? I’m guessing that’s the lightest grip available.

WAIT!! Am I seeing that right?? 11.3oz after building out the lower?? What buffer tube is that? I think the buffer is a Tacom just like I’m using. But my tube is a standard one which is heavy.
 
TACCOM buffer started as a AR15 but cut down to AR308 overall length. Stock is Incognito Arms and the 3D printed from Form3D Firearms.
3D7495oz.jpg
 
I haven't shot 6.5 Creedmoor for over 4 years, and that was a 26" Shilen Select Match bolt gun @ 12 pounds.

Going to use cheap S&B ammo to sight in the scope and start the break in process. The Faxon QPQ barrel coating takes a different approach to break in.

What is the best most accurate 5.5 Creedmoor factory ammo? I am assuming the Federal Gold SMKs and the Hornady ELD Match ammo will be the most accurate, they are in 308!
 
S&B is perfect break in ammo. I would guess you are correct about Federal and Hornady ammo being the most accurate match ammo. I’m strictly a handloader so I have not used any factory ammo in it yet. I wish I could tell you how my Faxon 5r barrel performs with match bullet handloads, but I can’t just yet. My life got derailed last year when my wife of 27 years decided to mentally go back to high school which lead to some interesting behavior which led to divorce; that’s the short story. I can see a lot more range time in my future and ringing the last bit of performance out of this AR10 is on the top of the list. I have H4350 and Nosler match bullets waiting to be loaded. As of now, I’ve only shot hunting bullets in it, other than break in.

Btw, I departed from Faxon’s break in procedure and after shooting 5 rounds and copper cleaning between each one, I did the following. We will see how well it worked when I get to testing match bullets.


http://theclaymore5150.blogspot.com/2013/04/breaking-in-my-new-rifle-another.html
 
That's basically the way I break in barrels, every 5 shots. After 30-40 the first day a good copper cleaning.

The Tennessee Arms polymer lower is very inexpensive under $50 and the 2A Xanthos $278 with the LEO-MIL discount.
 
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Have any of you shot lightweight carriers and buffers suppressed and tested accuracy? I got a JP FMOS carrier and LMOS to see what would work best. Also have you guys with lightweight all steel barrels had issues shooting 10 shot strings due to barrel heat?

Also, just wanted to add 6.5 140 grain Hornady ELD-M is some of the most accurate factory loaded ammo I have ever shot.
 
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I have not yet tried shooting my 6.5 suppressed; I likely will in the future as I have a AAC7.62SD, but I want to test match loads unsupressed first. For certain when I do, I will turn the gas off and start the tuning process over from the beginning. I too wonder about the 10 shot displacement of a lightweight pencil barrel as it heats up, that’s why I went with a fluted match barrel. The groups breaststroke’s is getting with his are very impressive.

If I could figure out how to make those carbon fiber handguards like breastroker and I had used a 20” pencil barrel this gun would be well under 6#; probably very close to 5#. For a walk around hunting gun, that’s very tempting. I’ll be building a 16” 308 this summer, but it will have a Faxon Gunner barrel which is medium weight behind the gas block and pencil on the front.
 
Other than hog hunting, I can't see a need for 10 shot groups. Pencil barrel is good enough for 25 shot Zombie groups.

I have had a medium Faxon 18 inch 308 barrel, a fluted Juggernaught Tactical 18 inch barrel, even a fluted heavy DPMS SASS barrel, and they all spread a little due to the heat generated by 308 ammo. Normally 3 times the bullet weight and double the powder of a 556.

But if you start out with an accurate barrel your groups will still be more accurate than a crappy barrel.
 
Next I will state no matter what the rifle weight, shooting with a properly set up lighter weight action system (BCG+buffer) and an adjustable gas system with a good recoil reducing muzzle brake will allow for the most accuracy possible.

I equate an AR15 action like a ball peen hammer, a stock AR308 action like a 10 pound sledge hammer! Everything including the buffer spring is too powerful in a stock AR308. Remember the bolt surface that receives the gas from the gas tube has 4 times the surface area of an AR15 bolt. Combined with a larger barrel gas hole and the 23 to 25 ounce action weight of a stock AR308, the action spring has to be super strong to push all that weight back into battery. Shooting a stock AR308 is difficult as there is so much hammering going on.

But my latest aluminum JP VMOS carrier and polymer buffer weighs LESS than a stock AR15 action, and combined with an adjustable gas block and great muzzle brake my recoil is less than my AR 6.8 SPC II. I typically shoot with an 18 to 35 power scope. To get back on target quickly low recoil is very important.

If you are hog hunting a lower power scope is needed, and the accuracy for the pencil barrel (or medium wt) is fine, it's not like you are making 500 yard shots on hogs. Plenty of accuracy for under 200 yard shots.
 
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icon1.png
Weight of 89.28 ounces or 5.58 pounds
Just got my new 2A Xanthos upper @ 254 grams or 8.95959 ounces. Easiest upper to lap ever. Upper with Faxon 6.5 Creedmoor barrel, V7 Furion titanium barrel nut, BAD titanium gas block and rifle gas tube. Using an aluminum barrel nut and a 14.5 inch CF handguard. Total weight without BCG and CH is 57.70 ounces.

Will be using the Toolcraft Ti BCG @ 11.18 ounces and a Strike Industries CH at 1.40 ounces. Total of upper 70.28 ounces or 4.4 pounds.

Lower will be a Xanthos with closed Smoke Composite stock titanium takedown pins and polymer buffer tube. Lower weighs under 19 ounces.

Total weight of 89.28 ounces or 5.58 pounds.​
 
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I can’t seem to find in your posts which Faxon 6.5 barrel you have, is it the Pencil wt. or 5r fluted match?
Thanks!

Just looked on Faxon’s website and I no longer see a 6.5 pencil barrel listed.......what’s up with that?
 
The Faxon 6.5 Creedmoor barrel I have is their Big Gunner Match Series at 18 inches. Listed at 2.46 pounds actual weight 39.20 ounces. Twist 1-8 with 5R 416R melonite coated. #FF2625
 
Thanks! Mine is the 20” heavy weight fluted match that’s 2.52 #, or 40.32 oz. it’s nice to know I can shave even more weight off my rifle if I want. I thought Faxon made a pencil 6.5, but maybe not. 2A has a lightweight 20” 6.5 barrel that weights 35.4 oz. Thats the lightest one I’ve seen recently. I wonder if Faxon actually makes it for them?
 
I also would bet Faxon makes the 2A barrel. I wanted a medium weight Match series barrel in Creedmoor, figure it would be slightly more accurate than the 2A. With the 2A barrel I would have gone on for lighter weight components and built the rifle about 5 pounds. I also think Toolcraft makes the 2A titanium 308 carrier.

Your 20" fluted Creedmoor barrel is only one ounce more than my 18 inch, again I could build an AR6.5 Creed at 5 pounds using all my absolutely lightest parts.

Just I really like the rifle about 5.5 pounds, either AR15 or AR308/6.5. Even with heavier more powerful scope the rifles weighs under 7.5 pounds loaded with 10 rounds.

One of the reasons I got the 18 inch Match is it was on sale @ $219. But even at list price the 20 inch fluted is a great price as well as an amazing light weight.
 
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You might try the Anarchy Outdoors 35 hole spiral titanium muzzle brake. Only 0.7 ounces and it really works great. Looks like the Weatherby brakes but will make your 20 inch as light as my 18". I have an older V7 Furion 2 chamber brake on the barrel now. Trying to keep the build costs down and I know the Furion works great. I could use my super ultra light weight CF 11 inch hand guard and cut 2.5 ounces but since this uses a rifle gas tube it will look better with the medium wall 14.5 inch CF hand guard.
 
I'll have to look at that Anarchy Outdoors muzzle brake. I'm using a 2A X4 Titanium brake but at 1.7 oz you are correct, if I used the Anarchy brake, my barrel weight would drop by 1 oz. Every ounce counts. I got my Match barrel on sale at Brownells, otherwise, I might have gone with a Gunner. For me, the next big weight reduction will come in the handguard. Still need to find something really light or figure out how to make my own like you did. Thanks!
 
Actually lighter than 0.70 ounces. I have several in raw titanium and a couple in black. The AR15 version weighs more at 1.15 ounces.
 

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Weight of upper complete came in at 4.30 pounds. Going to use a BAD titanium gas block, making it "tuneable". I did the tuning thing several years ago on an AR308, tapping the gas hole in the gas block from the bottom. Taking out the allen and tapping into the titanium and then installing a allen with a smaller hole drilled into it. Then inserting the drilled allen and assembling. There is a company that has the "tunable gas block" but doesn't use titanium that I wanted.

The 308 ended up great with bullets between 110 and 178 grains, a 68 grain spread. Really helped control the recoil with the lighter BCG.

Figure on the 6.5 Creedmoor it should work even better as I will be using between 120 grain and 147, a 27 grain spread.
 
Tools needed:

1/8 inch drill bit
9/64 inch drill bit
5/32 inch drill bit (good one recommended)
8/32 starter tap
8/32 bottom tap
3/32 stainless socket set screws 1/8" depth
1/16 inch drill
Tap wrench
Cutting fluid

The 2A titanium has 8/32 set screws, the rear one is in alignment with the hole drilled into the bottom of the gas block. The major diameter is 0.1640 inches.
But instead of the hole being the same as for a 8/32 tap of 0.1389 inches, 2A uses a drill less than 1/8 inch.

No way you can tap for 8/32 into 0.125. So I first drilled out using a 9/64 drill, then switched out to the 5/32 and then used the 8/32 starter tap.
Lots of cutting fluid. I did mine by hand and left the gas tube in. A lot of heat generated. Finished up with the 8/32 bottom tap.

Drilled a couple of 3/32 stainless socket set screws with my 1/16 inch drill bit, again using a lot of cutting fluid. I am using the smaller range of recommended drill sizes because the 308 has a LOT more powder compared to a 6.8. But you can try sizes like 0.68, 0.70, 0.71 inches for a 556 or 6.8.

Finally I screwed the 1/8 inch deep 8/32 set screw into the gas hole, tight against the gas tube. There are at least 1 to 1.5 threads left.

TOOLS:
http://i1237.photobucket.com/albums/ff464/brasse/Tools_zpsdjexoqxf.jpg (http://s1237.photobucket.com/user/brasse/media/Tools_zpsdjexoqxf.jpg.html)

2A with 0.0625 hole in set screw to gas tube:
http://i1237.photobucket.com/albums/ff464/brasse/2Awiithset screw_zpswrzpkldd.jpg (http://s1237.photobucket.com/user/brasse/media/2Awiithset screw_zpswrzpkldd.jpg.html
 
Weight of upper complete came in at 4.30 pounds. Going to use a BAD titanium gas block, making it "tuneable". I did the tuning thing several years ago on an AR308, tapping the gas hole in the gas block from the bottom. Taking out the allen and tapping into the titanium and then installing a allen with a smaller hole drilled into it. Then inserting the drilled allen and assembling. There is a company that has the "tunable gas block" but doesn't use titanium that I wanted.

The 308 ended up great with bullets between 110 and 178 grains, a 68 grain spread. Really helped control the recoil with the lighter BCG.

Figure on the 6.5 Creedmoor it should work even better as I will be using between 120 grain and 147, a 27 grain spread.

Why not just buy a titanium adjustable gas block like one of these from SLR
 
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Why not just buy a titanium adjustable gas block like one of these from SLR

$152.99, $152.99, $152.99 ,$152.99 That's why. Rather spend the money on a good barrel and lighter BCG.

They claim 0.70 ounces but I doubt it as they have a lot of steel parts on top of the titanium. I would expect 1 ounce or more for the 0.750 adjustable gas block
Sentry .750" Set Screw Version - Titanium
.400" Set Screw Spacing
0.7 oz
Grade 5 Titanium
 
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Just ordered 5 boxes of Federal with 95 grain Hornady V Max bullets, only $18.36 each, much less than the Hornady and the CC 95 grain ammo with Hornady 95 grain V Max bulletsl
 
Just bumping this to the first page since there has been a lot of threads lately inquiring about light weight builds
 
Wow that’s a new product. Didn’t know about that, thanks.



Not sure what buffer to tell you. If it has enough adjustment range, I would try the Tapcon like I have, but I would open it all the way up first. Might try calling 2A, they are very nice guys and probably would have some suggestions.
 
No, actually, it’s not. Again, I didn’t know taccom made one specifically for the AR10; it must be a newer product. I used the one they make for an ar15, but this one for the AR10 should work fine. Seems a lot of new stuff has hit the market.

I understand the port on the bolt carrier can be fully opened, but the question will be what force is applied on the carrier even when the port is fully open? I do not have any experience with ported carriers, so I have no idea. I assume, and I could be wrong, that even fully open, the carrier will still have some amount of force applied. With an adjustable gas block, I can completely block the gas to the carrier and tune by opening it one click at a time, I’m not sure it will work that way with a ported carrier.

Again, I would call 2A and ask them if a fully open port on their carrier will vent all of the gas without applying too much force on the carrier.
 
I'm working on it no on ever answers when I have been calling of late. Do they make an ar-10 kit of spring and detents I can buy for my lower and bolt catch and who makes the best one? It seems I have a whole lot of parts and no detents and few springs. Thanks
 
Finally shot today before the winds got over 25 MPH and the rain came. Slightly different configuration with a PDW buffer tube and a Rogers Super Stock. Using a 0.9 ounce buffer without weights. I was shooting in 20-25 MPH winds from the right, using factory Hornady 147 ELDM ammo. Took me 18 rounds to get the scope adjusted and get the first bullseye. From there about 1 MOA two 3 shot groups. Ejection ended up at 3 PM not using an adjustable gas block yet. Using the Toolcraft 11.18 ounce BCG.

I missed the feel of my SSA-E triggers so going to replace the lighter Hiperfire trigger with the 2 stage SSA-E trigger. Also switching to the JP bolt.
7046424

7046423
 
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Treetrimmer, I didn’t get too wrapped up in regards to springs and detents. I bought a DPMS lower parts kit for AR10 and used the springs and detents from it. Can’t remember what bolt catch I used, but it’s listed at the beginning of this thread in the parts list if I used something special.
 
Hey guys, I just ordered a 2A receiver set and Xanthos handguard. Hoping to do a lightweight build for deer hunting. I normally use a POF 308, and just last year a Grendel SBR. Had good luck with both, but the POF is too heavy to tote around the KY hills and woods, and I want something a little more substantial than the Grendel to plink with also.

I haven't settled on a barrel, but enjoyed reading all the comments, unsure if I'll go 308 or CM at this point. Can anyone with the Xanthos handguard tell me what they used to install the barrel? As in what kind of wrench was required? I have a magpul wrench, but saw the 2A Youtube video and they recommended a crow's foot instead. I know the 308 is probably a little different, but the 2A site had very little in the way of directions.
 
Just got confirmation the 95 grain Hornady rounds from Federal are finally in at Midsouth. $18.20 for the federal vs. $26 for the Hornady with the same bullets.

Also Form3D had the titanium pistol grips with black ceracote blemish for only $64, weighs a huge 1.1 ounces. I got mine and couldn't see the blemish? In 2017 the lightest pistol grip was the MagPul K grip at 2.25 ounces. Half the weight and grip feels amazing.

V7 just came out with some new ultralight handguards, lighter than most CF handguards.

The 2A Arms 20" 6.5 Creedmoor is the lightest out there @35 ounces. The Faxon 16" 308 and their 18" Creedmoor are more than accurate enough for hunting, sub MOA with target ammo.
 
Wait long enough and the answers come to you! 2A sent me instructions with the handguard - the barrel nut uses a 1 3/8 inch crowfoot wrench, which Amazon had nice and cheap. I've already lined it up. I also managed to find one of the 2A Creedmore pencil barrels on sale at Locked & Loaded, and am awaiting delivery for that. I also got one of the 2A bolts, found out my receiver had the "blem" meaning the detent hole was a little off so they sent it to me for free. I wouldn't have noticed had I not checked their site. Excellent customer service from 2A, and the bolt saved me 300 plus. I'll try and post pictures once the build is together. I badly want a scope too but I think that's gonna have to wait until next tax time. I have a Viper and a VX-3 laying around, they may have to be used this hunting season in the meantime.

Thanks to you guys for your Taccom advice, I'm on the waitlist for their light 308 buffers. I also purchased a superlative arms adjustable gas block.

As far as a scope to mount, any advice on something light and quality but that can be used to plink with in a pinch? I put together a wish list this weekend. Not sure if I'll end up with one of these or not, but I'm open to advice. I'd like to stick to 25 ounces or less, and minimum 12-15 max power.

I got these prices using gun.deals.
ModelWeightExit PupilFOV at 100 YardsEstimated Cost
Meopta Optika 6 2.5-15x44
27.3​
11 – 2.939.9-6.9 ft$ 550.00
Leupold VX-5HD 3-15x44
19.2​
38.3 - 7.9 ft$ 742.00
Leupold VX-5HD 3-15x44
19.2​
38.3 - 7.9 ft$ 816.00
Swarovski Z5 3.5-18x44
15.9​
30.6 - 10.2 ft$ 1,100.00
Leupold VX-6HD 2-12x42
16.8​
57.50 - 10.20 ft$ 1,300.00
Zeiss Conquest V6 3-18x50
22.2​
9.5 – 2.837.2 ft – 6.3 ft$ 1,400.00
Leupold VX-6HD 3-18x44
19​
38 - 7 ft$ 1,420.00
Leupold Mark 5HD 3.6-18x44
26​
28.4 - 5.8 ft$ 1,454.00
Leupold VX-6HD 3-18x50
20.4​
38 - 7 ft$ 1,500.00
Leupold VX-6HD 4-24x52
22.5​
28.1 - 4.8 ft$ 1,572.00
Nightforce NXS 2.5-10 X 42
20.5​
15.5 - 4.444 - 11 ft$ 1,900.00
March Optics FFP 3-24x42
21.5​
X - 1.7535.0 - 4.3 ft$ 2,525.00
 
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My favorite scope is the Leupold Mark AR MOD 1 Rifle Scope 6-18x 40mm 1/10 Mil Adjustments Adjustable Objective Matte. Unfortunately it is discontinued. You might be able to find one though. List was $750, Optics Planet has 14 left @ $449. You get free shipping and many times you can get a 10 to 15% discount.
They also make a 14 power.

Only 15.1 ounces and really nice lenses. The Aero Precision mounts are the lightest.
 
Thanks for the suggestion, looks like a very nice scope, and the price is incredible. Unfortunately I need a minimum power no greater than 4. I had to make a 30 yard shot once with a 6.5 -20 power scope, and the field of view and panic wasn't pretty on my part finding and taking it while the doe was moving. Thankfully it worked, but I pretty much swore I'd never hunt with a scope again that doesn't go lower in power, at least here in KY where long shots aren't very common.
 
Josh, The AR Mod 1 is made in several powers, all you have to do is Google
 
Josh, The AR Mod 1 is made in several powers, all you have to do is Google
Thanks, I have, quite a bit. I have looked through some as well and found that the one inch models have a tighter eyebox, and the eye relief varies with magnification, at least to my horrible eyes. My preference is to stick with a 30mm+ tube and a more premium line since I'm all ready splurging on the AR build.

I'm probably asking for two much given my low weight but lots of features desire, but that's part of the fun of the research and learning from others.
 
There is no such thing as a true light weight scope in 30MM. Same with a 50mm objective. Leupold weights are usually right on. There are others who lie thru their pie hole.

Like the 30 MM Sightmark 6-35 power they claimed weighed 15 ounces, actual weight was 38 ounces!

I can say from experience my Leupold Mod AR scope has a longer eye relief than any of my larger Vortex Viper scopes. Their 1-4 and 3-9 have huge eye relief. From experience you don't need more than 4.5 inches, even 4 is a LOT!!
 
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I mainly like the eye relief to stay the same, rather than worry about what actual length is. I don't shoot any magnums and have never had issues with scope kiss up to 30.06 which is as big as I shoot. But I agree on the Viper assessment, I've had two now, sold one, and would like to get rid of the last, but mainly due to the reticle. Its a Viper HS 2.5-10x44, and its a nice 16.5 ounces, 30mm tube. That to me is light. I have a Tango 6 thats 38, and then a S&B PM II thats 40 ounces, but those are both 34mm.

I may end up compromising as this build is perhaps light enough to get by with a 22 - 28 ounce scope, we'll see. I just enjoy the journey figuring it out. Let's face it, when a lot of us finish a project, we move on to planning the next, as least that's my problem. The safe ain't getting any roomier! ;)
 
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Shot yesterday, 90 degrees and winds less than 5 MPH. Used a box of Federal 95 grain Hornady Varmint ammo. Best group was .75 inches, but 5 inches from the bullseye LOL. The left right adjustment knob on my expensive Viper scope just spun, in fact actually came off in my hand. Rifle woked great with 3 O'clock ejection. Also had an issue with bolt catch, wouldn't hold with the stronger 308 spring but fed perfectly. Switched to a lighter spring and wouldn't bottom out the bolt against the barrel extension.
So like Goldilocks I have to find a spring just right, or cut the to strong spring a coil.
 
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Midsouth Shooters Supply has all the Leupold Mark AR scopes on sale now between $70 to over $100 off
 
I was boored so I purchased a 2A 20" Creedmoor barrel, was 4 ounces LESS than the Faxon 18" barrel. Did some other magic and got the weight of the rifle down to 4.9pounds.
 
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I wish I could get to a season of life where I was boored. I haven’t had time to shoot mine since last summer. Ever time I think I see more free time coming in the near future to head to the range, something else more than fills that anticipated “void”. Have fun with that 4.9er. I wonder who makes that barrel for 2A? Faxon maybe?