Building my first semi .308

[SDLocal76]

I am going for as lightweight as possible. Right now I have a 16 medium contour barrel spec'd but I would like a 14.5 as I am in Cali I don't have access to super long ranges and I think it would be fun to have. Building around a Maten Monolithic matched set.

Based on my research I am no longer sure about the 14.5 because people seem to say the that the muzzle blast is like a tactical nuclear weapon detonating next you your head....how bad is it really? Is it that much worse than a 16? I am struggling with the muzzle device as well....but it seems the battle comp maybe the way to go....I don't want a full comp due to noise and then if I go with a flash hider it will be the noveske 3 prong that does not ping....

Part Description Price Weight in lb Pattern Company
Barrel 16in melonite med profile mid gas $310.00 2.56 Sr25/dpms Mega arms
Gas Block .750 adjustable gas block $125.00 0.08 N/A SLRRifleWorks
Upper/lower set Monolithic billet upper/lower ext length (14in) $818.00 2.74 Sr25/dpms Mega Arms
Charging handle Inc in reciever 0.00
Dust cover Inc in reciever 0.51 AR15
LPK AR15 lower parts kit $63.00 0.00 RRA
Bolt carrier group Complete bolt carrier group (change WMD) $389.45 2.25 Sr25/dpms LMT
Trigger Super Semi-Automatic Enhanced (SSA-E) Trigger $230.00 0.00 AR15 Geissele
Buffer and spring Heavy carbine buffer and spring $99.00 0.34 Sr25/dpms Heavy Buffers
Buttstock CTR Stock with enhanced butt pad $80.00 0.06 AR15 Magpul
Buffer tube ext Milspec buffer tube carbine (weight inc with buttstock $47.00 0.00 AR15 Vltor
Grip MAID type 2 $36.00 0.02 AR15 Magpul
Scope Viper PST 2.5-10x32 FFP (reticle?) $799.00 1.17 AR15 Vortex
Mount LT104 $210.00 0.44 AR15 Larue
Red dot Attachment La Rue FastFire Attachment LT137 $75.00 0.01 AR15 Larue
Red dot Fast-Fire III Reflex Sight - 1x, 3 MOA $226.00 0.06 AR15 Burris
Castle nut Lightweight Castle Nut $22.00 0.00 AR15 V7
Endplate ? 0.00 AR15 ?
Muzzle device Battle Comp BABC $220.00 0.18 Sr25/dpms Battle Comp

current total weight:10.42lbs
current cost: $3,749

 

[SDLocal76]

Did in post in the wrong spot. I sincerely would like some feedback on 14.5 vs 16 and thoughts of battle comp vs flash hider if my main use is range work both indoor and out and some matches.

 

[Trochlea]

you didn't post this in the wrong spot but ill respond to what what i think your questions are and then an observation or two.

First the 14.5 vs 16 hs been discussed ad nauseum here and other places. 14.5 really doesn't offer that much of a benefit over a 16 for a 308 you have to ask yourself why push to the higher caliber and costlier bullets and then cut the legs (the speed) out from it? Unless you are using this for a heavy division 3 gun, I don't know of any match that would benefit from dropping the barrel length below 18. considering the weak performance of the 30 caliber compared to the 6/6.5, adding the complexity of a gas gun, and then neutering the speed with a short barrel seems like a combination for frustration in a typical tactical/long range competition. if this is just to shoot expensive bullets at close ranges, sure drop a 14.5 inch barrel on it and go to town.

Compensator vs flash hider - well they arw for completely different purposes. the flash hider is to reduce the muzzle signature of the gun, the compensator is to transform recoil energy into the discomfort of those standing around you. Are you trying to stay on target? Grab a compensator, but a compensator/ brake will not be nice to those standing around you. i don't think that an inch on the barrel is gonna be much different but the shorter the worse on average. I would not want to be shooting indoors with a brake on a 308, much less a short barreled 308 and even less would i want to shoot next to one. An effective brake will be loud and concussive to neighboring shooters. I am still trying to figure out why in the world at any reasonable indoor range you would be spending any time behind a 308. On paper, indoors, at less than 200 yards, the 308 offers absolutely zero advantages. you don't gain measurable benefits until you starts adding things like distance and environmentals, and by distance I mean 2-300 yards at the very least. Hell at 100 yards indoors you could be shooting rimfire. That's neither here nor there, but long story short, if noise is a concern, a compensator is out of the question, regardless of barrel length. 14.5 vs 16 is not an appreciable change, especially in a 308.

Now for unsolicited opinions- your build is unnecessarily expensive. Ill review a few points and if you don't care then you can stop reading here. BUT since you asked here is my opinion. Take it for what its worth.

You have are spending 1500 on alot of optics. since you are not shooting out to range and have an short barrel with slower speeds to match, just get a 1-6 like the primary arms with some back up iron sights and knock a full grand off of your build. The 1-6 will take you to 4-500 yards easy and if you want to shoot past that you need to rethink your build anyway.

As far as pricing goes, at 3.7k you are in the land of GAP 10' and other similar performing rifles. In this price range, i think you would be better suited going with them. If you would like to decrease your cost there are a couple of areas to look at. You have are spending 1500 on alot of optics. since you are not shooting out to range and have an short barrel with slower speeds to match, just get a 1-6 like the primary arms with some back up iron sights and knock a full grand off of your build. The 1-6 will take you to 4-500 yards easy and if you want to shoot past that you need to rethink your build anyway. Your barrel seems about 100 higher than midway. You could likely find the same barrel for less. Also if you are going to get a short generic barrel, 400 is a lot for a BCG. You could go much more economical without hindering performance. Same for your buffer system. grab a JP spring a 308 carbine buffer and you will be golden.

Your parts kit is the wrong parts kit. The bolt catch release will not interchange with the ar15 - dpms lr 308. Nor will the front and rear takedown pins for that matter. Go for a dedicated 308 kit, I recommend the CMMG kits. but really any 308 kit will do.

If doing a short plinking set up I would end up with something like this

https://www.primaryarms.com/WMD_308_NiB_X_Bolt_Carrier_Group_Polished_p/308-bcg-mpi.htm
https://www.primaryarms.com/Radical_Firearms_308_Carbine_Buffer_p/rf308carb.htm
https://www.primaryarms.com/Yankee_Hill_Phantom_Flash_Suppressor_w_o_Teet_p/yhm-3080-5c1.htm
https://www.primaryarms.com/LBE_Unlimited_308_Crushwasher_p/lbarcw-308.htm
https://www.primaryarms.com/Rainier_Arms_Select_308_16_416R_Black_Stainless_p/ra-sel-308-16.htm
https://www.primaryarms.com/Magpul_CTR_Carbine_Stock_Mil_Spec_Version_Steal_p/mag310-gry.htm
CMMG LR-308 Customizable Lower Receiver Parts Kit
DPMS Receiver Extension Buffer Tube 6-Position AR-15 LR-308 Carbine
DPMS Receiver Extension Buffer Tube Lock Ring AR-15 LR-308 Carbine
DPMS Receiver Extension Buffer Tube End Plate AR-15 LR-308 Carbine
JP Enterprises Tuned Polished Buffer Spring AR-10 LR-308 Carbine

which in total comes to a whopping 669. Add in your adjustable gas block, receiver set, trigger and grip and you are at 1880 before shipping or any discounts.

Throw this scope and mount under and you are hitting 2300

American Defense MFG, LLC | Browse | Primary Arms Combos | Primary Arms 1-6x (Gen 2) Scope / AD-Recon X 30mm Mount

2400 if you add a buis set
Amazon.com: mbus gen 2 set: Sports & Outdoors

All in all you are at 1.3k under your original build without sacrificing any performance from the original posted build

 

[jasonfaz]

First of all, your build without optic is a very good list. Reminiscent of someone doing it right the first time. I think Troch made some good calls saving you a few bucks here and there, but for the most part, I think you're doing it right. I'd go 16" over 14.5 only because I'm one of those "if you're going to do something do it all the way" type of guys. Example, I went 12" and 13.5" on my 308 shortys (and am pleased with them both). I think 16" is a good length for middy gassers with respect to dwell time and external/terminal ballistics with the right ammo.

That said, I think there are some specific areas that you are making really good choices that most don't. 1st would be the A5 length buffer tube and heavy buffer. This one thing will make a HUGE difference in how enjoyable the rig will be to shoot. The spring from heavy buffers has the absolute best tension of any spring I've tried. I pay Clint to custom cut springs for every single semi auto I have. They make a huge difference. The SLR gas block is also a phenomenal choice. It's stupid light and it's adjustments are simple and fast. I have also recently bought some of the V7 stuff, and can genuinely say, I'm impressed. They have a receiver extension plate that you might want to throw in there.

I'm a huge fan of splurging on barrel, but I don't think there's a whole lot more you can do over the Mega without spending substantially more. The Rainier with Match chamber is only $5 more. So maybe, that. But overall it's a good choice with a 10 twist that will be great for shooting the heavy 185gr + out of it (which I'd recommend). Just FYI, the CTR won't fully collapse on a 7.75" tube. BUT, using a 1 1/4 Forstner/Auger bit or Plug Cutter you can take an extra .4" out of the enhanced pad so that it will fully collapse (i did this same thing).

The things I wouldn't personally do....
1. Ditch the Burris and Vortex and put more into a better primary optic. I shoot my 12" out to 500 yds with ease, but the 3-18 MK6 definitely helps. You can grab a Bushy HDMR 3-21 for $1k or so that would be right at home on a 16" 308. If you really felt the need for a close in type of transition sight, I'd sport a pair of KAC 45 degree offset BUIS.
2. If you're going to drop $230 on an SSAE you might want to check around for a deal on the Hi Speed National Match triggers. IMO, they're the best there is, and only $45 more than the SSA-E.

You're good on mount. I'd personally never buy an ADM mount as I hate their levers. But I would go Bobro dual lever before larue. But I do have a Larue LT 158 and have nothing but love for it.

3. Last thing would be brake. I love me the Precision Armament M11s. They are my all time favorite brake/comp/flash hider all in ones. The M41 is my favorite pure brake. The quality of those units is off the charts.

My 2¢. Hope it helped..

 

[jasonfaz]

....and FWIW, you're rig is a really nice set up without optic and mount that is running $2,349. That is significantly cheaper than the $2750 for a GAP-10 with standard A2 stock and 4.5 lb single stage trigger. You're saving nearly $1k and a 6 month wait by building it with your current config. Job well done my friend!

 

[Trochlea]

I will definitely defer to Jason and his experience on this one. Especially with regard to the buffers, barrels and triggers. I have a the Jp/radical buffer system combo and it works really well, but I don't have a ton of experience with other combos to tell if it works appreciably better or worse. I'm still trying to wrap my head around the whole light vs heavy set up myself.

I agree as well about spending up on barrels, never been at the range and wished for a cheaper barrel. Overall again I did not mean to downplay your build it's got a ton of quality parts.

The only thing I will say is that before you drop $200+ on a trigger I would make reasonable efforts to try it put first. Every one talks up geissele but I had my reservations because I didn't like the two stages. Tried a couple out and I was right, definitely prefer the one stage triggers. I would sit down behind a few and test them out if possible.


Sent from my iPhone using Tapatalk

 

[Skeld1]

First of all, your build without optic is a very good list. Reminiscent of someone doing it right the first time. I think Troch made some good calls saving you a few bucks here and there, but for the most part, I think you're doing it right. I'd go 16" over 14.5 only because I'm one of those "if you're going to do something do it all the way" type of guys. Example, I went 12" and 13.5" on my 308 shortys (and am pleased with them both). I think 16" is a good length for middy gassers with respect to dwell time and external/terminal ballistics with the right ammo.

That said, I think there are some specific areas that you are making really good choices that most don't. 1st would be the A5 length buffer tube and heavy buffer. This one thing will make a HUGE difference in how enjoyable the rig will be to shoot. The spring from heavy buffers has the absolute best tension of any spring I've tried. I pay Clint to custom cut springs for every single semi auto I have. They make a huge difference. The SLR gas block is also a phenomenal choice. It's stupid light and it's adjustments are simple and fast. I have also recently bought some of the V7 stuff, and can genuinely say, I'm impressed. They have a receiver extension plate that you might want to throw in there.

I'm a huge fan of splurging on barrel, but I don't think there's a whole lot more you can do over the Mega without spending substantially more. The Rainier with Match chamber is only $5 more. So maybe, that. But overall it's a good choice with a 10 twist that will be great for shooting the heavy 185gr + out of it (which I'd recommend). Just FYI, the CTR won't fully collapse on a 7.75" tube. BUT, using a 1 1/4 Forstner/Auger bit or Plug Cutter you can take an extra .4" out of the enhanced pad so that it will fully collapse (i did this same thing).

The things I wouldn't personally do....
1. Ditch the Burris and Vortex and put more into a better primary optic. I shoot my 12" out to 500 yds with ease, but the 3-18 MK6 definitely helps. You can grab a Bushy HDMR 3-21 for $1k or so that would be right at home on a 16" 308. If you really felt the need for a close in type of transition sight, I'd sport a pair of KAC 45 degree offset BUIS.
2. If you're going to drop $230 on an SSAE you might want to check around for a deal on the Hi Speed National Match triggers. IMO, they're the best there is, and only $45 more than the SSA-E.

You're good on mount. I'd personally never buy an ADM mount as I hate their levers. But I would go Bobro dual lever before larue. But I do have a Larue LT 158 and have nothing but love for it.

3. Last thing would be brake. I love me the Precision Armament M11s. They are my all time favorite brake/comp/flash hider all in ones. The M41 is my favorite pure brake. The quality of those units is off the charts.

My 2¢. Hope it helped..

The only problem with the Bushnell is that it's a lead sled. If you might want to actually carry this gun somewhere that's not going to help the situation.

 

[jasonfaz]

Very true. That bad boy is a hair over 2 lbs without even adding in the mount. I guess the point I was wanting to make is that I'd look into something in the 1-8/8.5x or 3-15/18x range on that rig. I consider each to be more versatile in different ways than the 2.5-10 optics. A bunch of people like them on 308 carbines though too. Something to think about that's all.

 

[SDLocal76]

Gentlemen,

Really great feedback. A couple of comments: I have settled on the 16inch but may change from mega to Black Hole. I could get a full fluting job to make it lighter but I lose the melonite which is a bummer. Optics: I did start with a 1-8 type optic on my list the us optics sr-8c has top on the list but quality seems to be a problem. Other optics in that style we're either too $$ or too heavy. The Vortex just seems like a good cost, weight, and function blend.

I will give all of your parts suggestions a serious review. I think the bcg could be less. Just to confirm a .308 bcg works with an ar15 buffer tube? The maten says it uses ar15 parts.

I really appreciate the guidance.

 

[SDLocal76]

Also per the maten thread over at arfcom the maten set come with pins and does not use .308 bolt catch it is designed for all ar15 lpk.

 

[jasonfaz]

Gentlemen,

Really great feedback. A couple of comments: I have settled on the 16inch but may change from mega to Black Hole. I could get a full fluting job to make it lighter but I lose the melonite which is a bummer. Optics: I did start with a 1-8 type optic on my list the us optics sr-8c has top on the list but quality seems to be a problem. Other optics in that style we're either too $$ or too heavy. The Vortex just seems like a good cost, weight, and function blend.

I will give all of your parts suggestions a serious review. I think the bcg could be less. Just to confirm a .308 bcg works with an ar15 buffer tube? The maten says it uses ar15 parts.

I really appreciate the guidance.

Depends on which ar15 buffer tube - specifically the length. There are the 7.75" (aka the Vltor A5 length tubes) or the 7" (aka std length buffer tubes). The A5 length will give you the option of using standard length AR15 buffers (3.5" long). The 7" standard length tubes will limit you to only the carbine length 308 buffers (2.5" long) or the 308 version of the JP silent captured spring - which with the spring kit it also a great option. Depends if you want to run your stock fully collapsed as many collapsible stock won't fully seat against the rear of the lower receiver with the longer A5-length buffer tubes. You also have a slight variance on spring tensions between the two, but that's probably something you should look at comparing after it's built as it's an upgrade that will encompass very little cost compared to everything else.

 

[Aye-Are-10]

Gentlemen,

Really great feedback. A couple of comments: I have settled on the 16inch but may change from mega to Black Hole. I could get a full fluting job to make it lighter but I lose the melonite which is a bummer. Optics: I did start with a 1-8 type optic on my list the us optics sr-8c has top on the list but quality seems to be a problem. Other optics in that style we're either too $$ or too heavy. The Vortex just seems like a good cost, weight, and function blend.

I will give all of your parts suggestions a serious review. I think the bcg could be less. Just to confirm a .308 bcg works with an ar15 buffer tube? The maten says it uses ar15 parts.

I really appreciate the guidance.

I just got my 18" mega barrel and it shoots great, it likes the heavier 175 smk's. I dont have a whole lot of rounds down range, but from the 75 I do have ive got a few sub .75" groups out of it.
Honestly, I dont think you can go wrong for the money. Just an opinion.. good luck.

 

[Cobracutter]

I would not do the build. The ONLY reason nowadays to build a large frame AR, is for precision/LR. This starts with the best barrel you can find and from there one. Might be cheaper to just go with a GAP or MWS.

For a Battle rifle with leggs, save yourself the money and get a SCAR17. Throw your optic of choice (no cheap shit) and it will do everything you want besides shoot 1/4" groups or sling 6.5cal bullets.

 

[355sigfan]

I just completed this build for a friend.



Its twice as accuracy as my SCAR 17 its lighter and recoils less. I would definitely build. This was the first AR10 I have done and it was a complete success. Before that I had just built AR15's. After this build for him I am giong to sell my SCAR and build an AR10 for myself with similar parts. Skip the Larue mount and go with Bobro. After using Bobro I will never use Larue or ADM mounts again. The 2.5-10 Vortex FFP is a great scope I have one on a AR15 that I like quite a bit.

 

[SDLocal76]

First part is ordered. I went with the 16 inch Black Whole Weaponry barrel medium contour and honeycomb fluting front and back of gas block. I think that going to be pretty light but stiff.