• Frank's Lesson's Contest

    We want to see your skills! Post a video between now and November 1st showing what you've learned from Frank's lessons and 3 people will be selected to win a free shirt. Good luck everyone!

    Create a channel Learn more
  • Having trouble using the site?

    Contact support

Where to start on large frame build

Scarface26

knuckle dragger
Full Member
Minuteman
Feb 14, 2017
427
207
Southeast OK
Gents,

I read thru Padom's thread on his budget .308 build - thanks, sir - and have also looked thru the first ten or so pages of this forum looking for info on putting together a .308. The amount of info is overwhelming.

Can anyone recommend a book for the process or point me to a thread that might answer compatibility issues between brands, etc. Seems like LaRue only works with their stuff, and according to a few posters, not very good at that.

At this point, I don't know what I don't know, and don't know what questions to ask, so, I'm looking to do the homework before I start asking questions in class.

Thanks in advance.

God bless America
 
I'm going to use Padom's budget of 2K and this is for banging steel out to 800 - is 1K doable? Also, is MOA ish accuracy with Federal 175's out of the question? Rifle should balance well - not relegated to prone only.

God bless America
 
Does the $2k budget include optics?

Unless you get really lucky I wouldn’t count on a sub $1k rifle shooting 1 moa to 800 yards. Either is feasible, but probably not both.

$2k should be pretty straight forward. I’d personally start with an Aero upper and lower (they often run sales). There are better receivers out there, but they have always worked for me.

Please remember that unlike ar15s not all ar10 parts are compatible - make sure your upper, lower, and handguard will work together.

Next decide on a barrel and gas block and a handguard with the same height as your upper that will clear your gas block.

Here is a good primer on what parts interchange between an ar15 and ar10:
 
  • Like
Reactions: SlowMover
Large frame AR's are a different beast than small frame for sure. You need to fo a lot more homework beforehand to make sure all the parts play nice together, but it sounds like you know that already.

As far as your budget and accuracy expectations, i think they are totally reasonable. I built my first large frame last year. I don't remember my budget exactly because i collected parts over a long period of time, but i would say I'm at $2,000 tops, probably under. My rifle is consistently sub moa with fgmm 168. Barrel is a 16" rainier match.

If i were you, i would pick the receivers you wanted to use first, as that will dictate what other parts will be compatible. One thing i did that I'm glad i did was use a vltor intermediate length buffer tube which allowed me to use standard ar15 carbine buffers. This gives you a lot of flexibility when you're tuning your gas/recoil system because you can play with different weight buffers.

Good luck with your build. I'm sure more people will chime in that can answer specific questions a lot better than i can.
 
Gents,

Thanks for the replies. The 2K budget was for rifle only. At present leaning toward Aero Precision upper and lower. I know I want a Geiselle SSA-E trigger. Everything else is negotiable.

God bless America
 
Aero is a great place to start. As already mentioned, there ARE better out there, but the Aero sets are well made and reliable. You can probably score a upper/lower/handguard combo sale and save yourself a few bucks. I know lots of guys like those geiselle triggers, I have not read a bad report. Personally, I have POF triggers in my AR rifles. The JP SCS is one thing I wish I had bought when building my AR10, instead of going with a standard spring and buffer.
 
$2k is used MWS money. Their chrome lined barrels seem to deliver +/- moa performance and their SS cut rifled barrels are better from my limited experience.
 
I recently did a “proof of concept “ gun to test exactly what you’re looking to do. I have several high end rifles, both gassers and bolts. I have several buddies who are younger guys, stay at home wives, younger children, whatever, but they cannot financially do a $7000 rifle. I absolutely understand. I wanted to see if a guy could build a decent, reliable gasser in the $1200-$1400 range. I definitely succeeded. This is the build I did: Aero upper/lower. I got this in a deal, and it was a .308. I already have a .308, and I wanted this to be a “poor mans long distance “, and to me .308 isn’t long distance. So, I rebarrelled it to a 6.5CM. The rest is fairly stock Aero. Aero m-lok rail, MagPul grip, trigger is a cassette drop in from CMC out of Texas. Excellent trigger. I had it sitting in an AR-15 that I don’t shoot, so I switched the triggers out.
Now I have an 18” 6.5CM that a guy can do for around $1200 I believe. The barrel is an 18” Ballistics Advantage, and it is absolutely sub MOA. Hornady 140 ELD-M leave the barrel at 2609. That puts me supersonic past 1000yds. I shot it yesterday at 630/700/800/1000 yds. Very comfortable gun.
I’m not going to sell my GAP-10, or anything crazy, but as I said, I wanted to know if it could be done, and even have a rifle to loan a buddy to get him shooting. The rifle is solid, accurate, and by long range standards, downright affordable.
 
For budget builds, M5E1 enhanced upper and lower with a Quantum handguard, all from Aero to minimize issues. Criterion barrels should get you MOA performance. There are others that will do it but Criterion did it for me. Aero's barrels seem to be hit or miss on making MOA so I pass.

Larue makes a nice yet inexpensive match trigger. The Rise Armament RA135 is a nice budget option too. Complete it with an Aero no trigger LPK.

Toolcraft BCGs can be bought for less than $150.

An adjustable gas system is a good idea.

The Vltor/BCM Gunfighter charging handle is a nice one to get.

The buffer and buffer tube is where it gets interesting. I'm a fan of the AR10 carbine setup on DPMS LR308 pattern rifles if you want a traditional buffer/spring combo. Armalite, Vltor and POF make suitable length buffer tubes for that. For the JP SCS (which is nice), an AR15 style buffer tube is what you want.

Buffer and tube is probably the #1 area where large frame ARs get screwed up so make sure you buy a compatible setup.

If you wait for sales, you can get all of that for $1,500 or less which is pretty good because not so long ago that's what a decent AR15 cost.
 
  • Like
Reactions: Potss
When it comes to guns and gunsmithing, I do lots of internet research before I start a project and before my first large frame AR I had built several AR15s that were all mix and match and pretty easy.

My first mix and match LR308 pattern rifle did not go together easily. I managed to have mostly compatible parts but fitting was required for a lot of things. Lots of draw filing, measurements and an upgrade here and there when I didn't like the way things were going together. Eventually it was quite good but not cheap and not the type of project you want if you aren't good with a file...

In the four ~Aero M5E1s I have built since, they have pretty much fallen together and I like the upper/handguard setup better.

The point is it doesn't have to be hard and unless you go full on bottom of the barrel parts, you don't save much and might even wind up spending more if you cheap out on the wrong parts.

I've heard of one guy who started with a complete PSA gun as a donor and wound up spending more than a JP would have cost after all the upgrades were done. That seems pretty silly to me.

Any way, research, create a plan, ask people if they see any problems and then repeat until no compatibility issues remain (and you still like the spec.).

My recipe is pretty simple, it works and it's at least price competitive with anything that has a good barrel, nice trigger and a good free float tube.

The only thing I would add is these guns are heavy unless you spend a lot on light weight parts. That's a battle that I don't want to fight so my LR308s are a bit hefty. You should understand that going in if you are planning to carry it.

If you need a light weight long distance paper punch, it's a lot cheaper in an AR15 shooting something like .224 Valkyrie.
 
  • Like
Reactions: acudaowner
My two primary bolt guns are 19-20 pounds each setup for the field ... back when I had my Sig 7.62(16) it was 15 pounds set up for the field ...
I carry the 19 pounders around at night ... in the field, crossing creeks ... slipping in the mud and ice (and not falling :D ) ... so hopefully I can carry the new 7.62(20) ...

With the aeros .. what barrel(s) did you use and what barrel nut and did it all fit well enough ?
 
  • Like
Reactions: Blaze2020
I think my 24" Criterion bull barrel (6.5 Creedmoor) mix and match LR308 pattern rifle weighs around 15 lbs with bipod and scope, maybe a bit less.

With a lighter barrel, smaller scope and no bipod, you can probably be less than 11 lbs if you chose parts wisely.

An AR15 might be under 9 lbs with the same amount of care.

That one uses a DPMS aluminum free float tube with the included barrel nut.

The others are an 18" Criterion in a M5E1 enhanced upper with a railed M-lok handguard, a 22" Wilson Combat fluted barrel in an M5E1 with a Quantum M-lok tube handguard, a KAC 16" .308 barrel in another Quantum M-lok tube handguard and a take-off barrel in another Quantum M-lok tube handguard. All 6.5 Creedmoor except the .308 and all use the M5E1 enhanced upper barrel nut.

That barrel "nut" is inverted and screws in to female threads in the oversized snout of the M5E1 enhanced upper while the free float tube slides over the snout and is attached with 8 flathead screws. It a far stiffer setup than the traditional AR15 style receiver snout with male threads but compared to most other large frame uppers with a barrel nut attachment style free float tube, it's only a very small cost premium. Some rails cost almost as much as the Aero M5E1 enhanced upper and the Quantum M-lok handguard.
 
Hey, I almost jumped in here and joined you ... :)
No sweat. Your questions and the answers they've generated are great. Were it not for the quality of thought in the responses, I would have deleted this thread.

One of my buds went on to fly for HMX. When he was a boot he briefed so thoroughly that we all asked him, "how do you know that you needed to know that?" That's where I am on this.

God bless America
 
depending on optics & barrel length, under 10 pounds (with optic and mount) is definitely doable, it all boils down to budget.

my recent, and long gestating build:
2A upper & lower
Geissele trigger (can't remember if it's a SSA or SSA-E)
JL Billet handguard
Ranier Ultramatch 16"
EFAB Hybrind muzzle break
VLTOR extension/emod/buffer
Troy ambi mag releases
seekins ambi safety & bolt release
Geissele 0moa rail & Nightforce NX8
(I can't remember where the LPK was sourced, or the gas block/tube, probably Brownells or Ranier)
Ergo grip

9.25 pounds with optic & mount w/o any accessories & mag.

I believe I could shave another half to three-quarters pound with a CF wrapped barrel and low mass BCG
more weight could be saved by going with a red dot, I think a Aimpoint Micro in a Scalarworks is something like 5 oz - that alone would shave a full pound off my build.
 

Attachments

  • IMG_0484.jpg
    IMG_0484.jpg
    54 KB · Views: 45
I’ve recently completed my large frame build in 6.5 Creedmoor. Pleasantly surprised with the performance. My rifle comes in at a little over 14 pounds (haven’t weighed it since I’ve mounted the new optic). Here’s what I’m running, as well as some load data I’ve developed.

M5E1 upper and lower from Areo Precision
18” Ballistic advantage barrel
SLR 15” MLOK handgaurd
SLR adjustable gas block
Stock nickel boron Aero BCG with the JP high pressure bolt and firing pin (must have for 6.5 CM builds imo)
Luth Ar fixed stock
Athlon Ares ETR.
Right at $3k with optic. I’m currently shooting the Berger 130gr Ar Hybrid over 38.6gr of Varget, seated at around 2.800 for a 90thou jump. This gives me 2715fps. Currently running lrp brass but plan on switching to srp brass now that I’ve got the hp bolt. I was seeing a lot of primer flow and pierced primers from the oversized firing pin hole and firing pin. All that went away after swapping bolts and firing pin. Best MOA from this setup has been .38 at 100yrds and a respectable .49 at 300. I’ve had no issues banging steel out to 870. I’ll include some photos.
 




 

Attachments

  • C9B8BE3E-F1A7-4F02-83BF-9F060EA90469.jpeg
    C9B8BE3E-F1A7-4F02-83BF-9F060EA90469.jpeg
    352.6 KB · Views: 42
Large caliber AR receivers (and subsequently the uppers) will be in one of two patterns, Armalite or DPMS. Make sure you know the difference and buy the parts that are compatible. A majority of manufactures are making their uppers and lowers in DPMS pattern since Armalite has trademark protection for "AR10". Chances are, unless you're buying an Armalite AR10 lower or a Mega MA-Ten upper/lower combo set (Mega is compatible with both patterns), you're looking at parts that fit the DPMS pattern. Always verify with the manufacturer if you're uncertain.
 
  • Like
Reactions: Scarface26
Not to hijack my own thread, but a chance to trade for a Rhino Arms AR-10 has come my way. Understand they're no longer in business, but most info on the inter web indicates that's not the fault of the rifles.

Jump on it? or run away?

God bless America
 
I’ve got around $2600 in my ar-10 build in 6.5 creedmoor, I’ve had hits out to 1350yds and 1000 was no problem on the first outing with the rifle, some of the parts I put on mine could’ve been cheaper and I think a 2k budget to shoot out to 8-1000 would be totally doable
 
Honestly dude, call SOLGW, sons of liberty gun works, in san Antonio, tell them what your wanting, then win. You'll get a properly built rifle with a lifetime no bs warranty that will run like a porn star. Mine holds .5 moa easily with fgmm.

There are very few places i would trust to build one, they are one.
 
Honestly dude, call SOLGW, sons of liberty gun works, in san Antonio, tell them what your wanting, then win. You'll get a properly built rifle with a lifetime no bs warranty that will run like a porn star. Mine holds .5 moa easily with fgmm.

There are very few places i would trust to build one, they are one.

I'll have to check them out. Cool name, and my Dad lives there.

God bless America
 
With an AR10 man buy a factory rifle. The AR10 isn’t the LEGO that the ar15 is. It’s not as forgiving. It takes some serious r&d to create a legit banger of an AR10.

I sold many-a-low-tier ar10’s in my career thanks to my demographic while LMT’s sat on the shelf and watched.

Many of those low tier rifles went back for warranty. Many reasons. No consistency whatsoever.

You can certainly throw together $2000 worth of mid/top tier parts and hope that your rifle works. Or you can spend that same cash for a rifle that’s legitimately been tested thousands of times to work time and time again.

You’d be a fool to build an AR10. You will lose at least 50% on a custom build that might not even function reliably.

Don’t build. Buy a reputable brand.
 
I have to disagree a bit, with smart shopping you can build an Aero M5E1 with a quality barrel, a "match" trigger and an adjustable gas system that will be every bit as reliable as an off the rack complete Aero M5E1 but more accurate and possibly cheaper.

I'm a bit skeptical of XYZ brand ARs having some sort of secret sauce that makes them more reliable. With quality parts and reasonably careful assembly I haven't had any reliability issues with my many AR builds.

It's to the point that quality parts are getting cheap so you can build a nice gun for what a budget build would have cost just a few years ago and they work so well I see no reason to pay a premium for a built AR (unless you just don't want to build).
 
Reliability is so extremely subjective in the AR10 world. What do you consider reliable? Two 10 round mags with no malfs over a 20min span?

Or 300 full auto rounds in <2 minutes.


We all have different expectations.

For those of you with the custom builds and the money to do so—please replicate.
 
If you end up building one... in addition to all the great professional courteous info here, Criterion has a very helpful video series.

While it is not specific to the .308 sized platform... the videos still have beneficial precision advice.

 
Understand all about building being complicated. Just because you can change a tire doesn't mean you can thread a barrel. But on the other hand, if you've got some instructions and don't try to use a big hammer to fix everything, and maybe a mentor, it might be something for the brave.

Probably end up getting a pro to put one together with parts that are known to work with each other and a quality barrel. At least after this thread I've got a list of pertinent questions to ask.

Thanks for all the replies and God bless America
 
My .02 cents

The more parts you can get from one company the more each part is engineered to work together and the more reliable it should be. Not that a mix of quality parts wont be any less.

Some hanguards wont work with certain uppers. Some buffer and springs wont work with some tubes, stocks/tubes, etc.

Some things dont matter. Any 308 trigger should fit any lower. Almost any barrels will work with any upper. Parts kits should be universal.

Start with a Matched Set upper/lower/handguard

Things that matter:
Barrel
Bolt
Bolt carrier
Gas block
Buffer spring
Buffer
Buffer tube

Everything else is personal preference.
 
Last edited:
Understand all about building being complicated. Just because you can change a tire doesn't mean you can thread a barrel. But on the other hand, if you've got some instructions and don't try to use a big hammer to fix everything, and maybe a mentor, it might be something for the brave.

Probably end up getting a pro to put one together with parts that are known to work with each other and a quality barrel. At least after this thread I've got a list of pertinent questions to ask.

Thanks for all the replies and God bless America

I'd be the cost savings from doing it yourself would more than pay for all of the tools needed to build future rifles, and you'll have the satisfaction of A) doing it for yourself, and B) knowing it was done right. go slow, and find someone local to check your work. I always have my dad do a secondary check on my new builds, and I've help several folks with the same service. it's an unnecessary step, but @ 44 years old I've learned the value of measure twice.

another reference point for part compatibility, just a point, not a bible:

as others have said:
start with an upper lower matched set, Aero is good to go and a great value
buy a handguard with the proper height. if you want to take the guesswork out of this, get one from Aero in whatever length you want.

you can buy a matching buffer from Aero too.
 
  • Like
Reactions: Scarface26
If you plan on spending $2k, look into a seekins. I have one and it's titties. I'm in the process of building an aero m5e1 to see if I can match the seekins. I have my doubts. The seekins is just much more refined. Is that worth twice as much? We'll see in a few weeks.
 
  • Like
Reactions: VegasHKShooter
  • Like
Reactions: 2aBaC̶a̶
Two things make an AR accurate: barrel and trigger.
Two things make large frames run well with a variety of ammo: high pressure bolts and correct gas (different calibers and different length gas systems, and different dwell times will all need different gas). Good AR builders know what to use where, many don’t. Adjustable gas blocks are pretty much a must if you’re going to change weights/loads/suppressed.

Research what fits what, because large frame ARs do not have a standardized spec like small frame AR’s.
 
  • Like
Reactions: Scarface26