AR10 completion kits??

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  • Mr.Culper

    Active Member
    Jan 16, 2021
    858
    AR10 308/7.62
    1st time builder,, so not comfortable piecing every bit needed.

    Probably headed to Nations Gun Show,, any chance "completion kits" will be there?
    what should I stay away from?

    Looking for 20-22 barrel, M4 style stock.
    Anyone have one they want to part with ?? or even the pieces, I would feel comfortable buy piece from a MDS member(s)
    Hook a brother up :)
     

    Mr.Culper

    Active Member
    Jan 16, 2021
    858
    OK,
    let me try another angle,,
    Is there a resource fr a 1st time AR10 builder? what to stay away from?

    Thanks,
     

    dfitzs1

    Member
    Mar 24, 2020
    61
    What do you mean by completion kit? Like all the parts disassembled and you put everything together?
     

    alucard0822

    For great Justice
    Oct 29, 2007
    17,643
    PA
    There are from "kits" a few places, but they aren't as standard as AR15s, so you may need parts that are AR10(ARmalite), AR308(DPMS high or low), AR15 compatible, proprietary or most often a mix. The places that offer kits usually have it paired to the receivers they carry or uppers/lowers in various states of assembly. It isn't hard to build your own if you have a couple AR15s under your belt, provided you know what standard they follow, have sufficient tools as some AR15 stuff won't fit, and what the "rules" are.

    The receivers/handguards have to be the same standard

    AR10(Armalite)- angular rear of receiver, 1 7/16x18 barrel nut, uses AR10 rifle and AR10 carbine gas tubes(slightly longer than AR15/AR308 rifle and mid length) different barrel dimentions

    AR308(DPMS gen1)- rounded rear of the receiver, 1 7/16x16 barrel nut, SHOULD use AR15 rifle and mid-length gas tubes, but occasionally uses AR10 spec tubes. Has high profile and low profile handguard/ rail height variants. The handguard and upper need to match the high/low profile as there is about 1/8" difference in height, some handguards that don't have rails on top, so nothing to match, others may use different hardware to work with both.

    Proprietary- this is the Sig 716, DPMS gen 2, Savage MSR and a few others, they usually have a shorter receiver being the AR10 and DPMS standards add about 1/2" to the LOP compared to an AR15. Proprietary stuff may have some parts in common with AR15s, AR10s or AR308s, but it varies.

    Best bet for a first time builder is probably Aero Precision's M5, it's DPMS high profile with really common parts, lots of kits, and relatively good mix of availability, performance and price. I've done a few and they are pretty easy without many of the pitfalls that other makes might have.

    Can simply use an Aero M5 builders kit or their upper/lower/handguard, then add a Ballistic advantage, Aero, Faxon or Criterion barrel, and build away.
    They use Aero M5 specific takedown/pivot pins, bolt catch, and the mag catch area is wider, so you need a longer catch or button(Kak's extended catch with AR15 button is best IMO). The FCG, selector, forward assist, castle nut/end plate, gas block,and detents are AR15, dust cover but the rear detent is above the grip, not at the end plate, and the hole is threaded for a 4-40 set screw to capture it, just clip a few coils if you use a set screw. The charging handle, mags, dust cover, and barrel/BCG are DPMS/AR308 spec.

    Then there is the buffer, with 3 different options. You can use any of the 3 on either brand, but there are benefits and problems to know about. With any, the LOP will be .5" longer than an AR15, not a big deal with collapsible, but something like the Magpul PRS3 will end up over 15" at minimum.

    AR10/AR308 rifle spec, Being the bolt has longer travel, and both use AR15 rifle tubes, the buffer is a little shorter than the AR15 rifle buffer, usually 5.5oz, and uses an AR10 or AR308 rifle spring. This is a good reliable option for fixed stocks.

    AR10 Carbine spec, This uses a longer buffer tube to make up the difference in bolt travel, A5 or AR10 carbine length is about 3/4" longer than an AR15 carbine tube, but same inner and outer diameter, so most any collapsible stock works. The UBR2 is A5 length and a great AR10/AR308 stock. This uses an AR15 H3 5.5oz buffer, and the same 308 rifle or AR10 spring used by the rifle buffer config. It is similarly reliable, but be aware the longer tube and longer LOP anyway will add more than an inch to the minimum LOP of some stocks, but being most still collapse down to 12" or so, it's not a problem.

    AR308 carbine spec, DPMS apparently wanted to use an AR15 carbine buffer tube badly enough to come up with this abomination. It uses a short, and usually underweight buffer and short stiff DPMS 308 carbine spring in a standard AR15 buffer tube. Avoid it if you can, some have had luck with it, but it can be tougher to tune, especially with the 4oz and lighter buffers most AR308 buffer kits include. The spring rates are not ideal, and the steel bodied buffer usually only has 2 steel or tungsten weights, so there is far less floating mass than an H3(3 tungsten) or rifle(5 steel) buffer. The floating mass keeps that big bolt from bouncing, and smooths out the chambering and recoil.

    Most build 6.5creedmoor or 308, and most things will work with both, but with ANY AR10/AR308 build an adjustable gas block is a good idea. There is a ton of gas and a huge range of pressures across the ammo selection, they also are a lot of fun to suppress. A good click adjustable block will make tuning, and sorting out some feeding and ejection issues easier. Bolts also can vary, standard have about a .075" firing pin hole, and some primer flow from hot 308 or 6.5 can jam it, high pressure bolts have smaller pin holes to solve that problem. The brass weighs more, and some bolts have larger or even dual ejectors to fling it out, they may or may not make a difference in reliability.
     

    Mr.Culper

    Active Member
    Jan 16, 2021
    858
    Many, Many Thanks for posting all that, it gave me a great bit of info.
    I will be reading and re-reading it,, a lot to soak in there.

    There are from "kits" a few places, but they aren't as standard as AR15s, so you may need parts that are AR10(ARmalite), AR308(DPMS high or low), AR15 compatible, proprietary or most often a mix. The places that offer kits usually have it paired to the receivers they carry or uppers/lowers in various states of assembly. It isn't hard to build your own if you have a couple AR15s under your belt, provided you know what standard they follow, have sufficient tools as some AR15 stuff won't fit, and what the "rules" are.

    The receivers/handguards have to be the same standard

    AR10(Armalite)- angular rear of receiver, 1 7/16x18 barrel nut, uses AR10 rifle and AR10 carbine gas tubes(slightly longer than AR15/AR308 rifle and mid length) different barrel dimentions

    AR308(DPMS gen1)- rounded rear of the receiver, 1 7/16x16 barrel nut, SHOULD use AR15 rifle and mid-length gas tubes, but occasionally uses AR10 spec tubes. Has high profile and low profile handguard/ rail height variants. The handguard and upper need to match the high/low profile as there is about 1/8" difference in height, some handguards that don't have rails on top, so nothing to match, others may use different hardware to work with both.

    Proprietary- this is the Sig 716, DPMS gen 2, Savage MSR and a few others, they usually have a shorter receiver being the AR10 and DPMS standards add about 1/2" to the LOP compared to an AR15. Proprietary stuff may have some parts in common with AR15s, AR10s or AR308s, but it varies.

    Best bet for a first time builder is probably Aero Precision's M5, it's DPMS high profile with really common parts, lots of kits, and relatively good mix of availability, performance and price. I've done a few and they are pretty easy without many of the pitfalls that other makes might have.

    Can simply use an Aero M5 builders kit or their upper/lower/handguard, then add a Ballistic advantage, Aero, Faxon or Criterion barrel, and build away.
    They use Aero M5 specific takedown/pivot pins, bolt catch, and the mag catch area is wider, so you need a longer catch or button(Kak's extended catch with AR15 button is best IMO). The FCG, selector, forward assist, castle nut/end plate, gas block,and detents are AR15, dust cover but the rear detent is above the grip, not at the end plate, and the hole is threaded for a 4-40 set screw to capture it, just clip a few coils if you use a set screw. The charging handle, mags, dust cover, and barrel/BCG are DPMS/AR308 spec.

    Then there is the buffer, with 3 different options. You can use any of the 3 on either brand, but there are benefits and problems to know about. With any, the LOP will be .5" longer than an AR15, not a big deal with collapsible, but something like the Magpul PRS3 will end up over 15" at minimum.

    AR10/AR308 rifle spec, Being the bolt has longer travel, and both use AR15 rifle tubes, the buffer is a little shorter than the AR15 rifle buffer, usually 5.5oz, and uses an AR10 or AR308 rifle spring. This is a good reliable option for fixed stocks.

    AR10 Carbine spec, This uses a longer buffer tube to make up the difference in bolt travel, A5 or AR10 carbine length is about 3/4" longer than an AR15 carbine tube, but same inner and outer diameter, so most any collapsible stock works. The UBR2 is A5 length and a great AR10/AR308 stock. This uses an AR15 H3 5.5oz buffer, and the same 308 rifle or AR10 spring used by the rifle buffer config. It is similarly reliable, but be aware the longer tube and longer LOP anyway will add more than an inch to the minimum LOP of some stocks, but being most still collapse down to 12" or so, it's not a problem.

    AR308 carbine spec, DPMS apparently wanted to use an AR15 carbine buffer tube badly enough to come up with this abomination. It uses a short, and usually underweight buffer and short stiff DPMS 308 carbine spring in a standard AR15 buffer tube. Avoid it if you can, some have had luck with it, but it can be tougher to tune, especially with the 4oz and lighter buffers most AR308 buffer kits include. The spring rates are not ideal, and the steel bodied buffer usually only has 2 steel or tungsten weights, so there is far less floating mass than an H3(3 tungsten) or rifle(5 steel) buffer. The floating mass keeps that big bolt from bouncing, and smooths out the chambering and recoil.

    Most build 6.5creedmoor or 308, and most things will work with both, but with ANY AR10/AR308 build an adjustable gas block is a good idea. There is a ton of gas and a huge range of pressures across the ammo selection, they also are a lot of fun to suppress. A good click adjustable block will make tuning, and sorting out some feeding and ejection issues easier. Bolts also can vary, standard have about a .075" firing pin hole, and some primer flow from hot 308 or 6.5 can jam it, high pressure bolts have smaller pin holes to solve that problem. The brass weighs more, and some bolts have larger or even dual ejectors to fling it out, they may or may not make a difference in reliability.
     

    135sohc

    Ultimate Member
    Oct 27, 2013
    1,157
    Within the 'Armalite AR-10' family there are two versions.

    The 'B' series guns and the 'A' series. They look similar, some big parts like the bolt carrier assembly and charging handle are the same. The magazine catch and bolt catch are completely different because of the magazine difference.

    The 'B' uses the modified M14 magazines, these are more or less no longer available and were $$$ when you could get them easily 5+ years ago now.

    The 'A' uses the more industry standard Magpul 308/SR-25/DPMS style magazines.

    Pretty sure when SAC bought Armalite from Mark Westrom they decided to abandon the 'B' series and shift everything to the 'A' series for obvious reasons.

    On a personal opinion I would avoid anything Armalite, they make (made?) a solid firearm with their flavor's of the "AR-10" but even with the 'A' series guns being much more DPMS inspired. As mentioned above already (a really good breakdown) they are still more proprietary than everyone else. I say this owning a 'B' series since 2013.
     

    alucard0822

    For great Justice
    Oct 29, 2007
    17,643
    PA
    Within the 'Armalite AR-10' family there are two versions.

    The 'B' series guns and the 'A' series. They look similar, some big parts like the bolt carrier assembly and charging handle are the same. The magazine catch and bolt catch are completely different because of the magazine difference.

    The 'B' uses the modified M14 magazines, these are more or less no longer available and were $$$ when you could get them easily 5+ years ago now.

    The 'A' uses the more industry standard Magpul 308/SR-25/DPMS style magazines.

    Pretty sure when SAC bought Armalite from Mark Westrom they decided to abandon the 'B' series and shift everything to the 'A' series for obvious reasons.

    On a personal opinion I would avoid anything Armalite, they make (made?) a solid firearm with their flavor's of the "AR-10" but even with the 'A' series guns being much more DPMS inspired. As mentioned above already (a really good breakdown) they are still more proprietary than everyone else. I say this owning a 'B' series since 2013.

    Haven't seen B series in a long time, but IMO some AR10 spec things are superior, the longer gas system and buffer setup being 2 of them. As long as you stick to the same brand receivers and handguard, you can stay out of trouble, and really can build either or provided you don't plan on swapping uppers between standards. Some Armalite pattern stuff like the Mega Maten and Zev are AR10 pattern and fantastic.

    Also should mention AR10 specific tools you should have.

    For any AR pattern build you want a good punch set, Armorer's wrench, CAR stock wrench, 3/4" crows foot(torquing muzzle devices) hex wrenches, basic hand tools, 1/2" and screwdriver torque wrenches, and a solid vise with non marring jaw inserts.

    AR10/AR308 stuff will need a vise block for the lower that fits in the magwell, lots of places make them. You use it for lower assembly, but you are better off using padded non-marring jaws on the sides of the lower for torquing the buffer tube to 40ft-lb. You can torque the tube with a magwell block, but you stand a chance of twisting the lower.

    For the upper, the locking lugs are larger than an AR15, front pivot lug is wider, and the pins are spaced further apart. You can use something like a wheeler vise block to put things together, but probably want something better for barrel nut torquing. a MI receiver rod is best, but plastix revolution vise blocks work well too, they clamp both sides in a vise, and are the best way to go for 9mm and 22 stuff that doesn't have locking lugs to engage in the barrel extension. To torque the barrel nut, USE THE CORRECT GREASE, if you do it dry, it can break or shear the pin, if you use something other than Aeroshell or equivalent aluminum safe grease, it can corrode and never come off. Most barrel nuts torque to 30ft/lb, back off, then torque again, then you can go up to 80 to align a gas tube. ALWAYS check instructions with proprietary barrel nuts, some have far less torque, might need to be timed/shimmed for the handguard hardware, or might not.
     

    Mr.Culper

    Active Member
    Jan 16, 2021
    858
    Thanks for the detailed response, I an learning from each post.
    I have a full shop, but no "AR" specific tools,, Though I have the machinery to make most specilized tools. I have always been a "Steel and Walnut" type of gun person, so the AR sean is new to me.
    My 308 lower is a DPMS pattern.
    Thanks for the warning on the grease.
    I do have rubber jaw covers,, I will research all the info on ways to hold the lower you gave.

    Once again,
    Many thanks and I will get to reading.

    Haven't seen B series in a long time, but IMO some AR10 spec things are superior, the longer gas system and buffer setup being 2 of them. As long as you stick to the same brand receivers and handguard, you can stay out of trouble, and really can build either or provided you don't plan on swapping uppers between standards. Some Armalite pattern stuff like the Mega Maten and Zev are AR10 pattern and fantastic.

    Also should mention AR10 specific tools you should have.

    For any AR pattern build you want a good punch set, Armorer's wrench, CAR stock wrench, 3/4" crows foot(torquing muzzle devices) hex wrenches, basic hand tools, 1/2" and screwdriver torque wrenches, and a solid vise with non marring jaw inserts.

    AR10/AR308 stuff will need a vise block for the lower that fits in the magwell, lots of places make them. You use it for lower assembly, but you are better off using padded non-marring jaws on the sides of the lower for torquing the buffer tube to 40ft-lb. You can torque the tube with a magwell block, but you stand a chance of twisting the lower.

    For the upper, the locking lugs are larger than an AR15, front pivot lug is wider, and the pins are spaced further apart. You can use something like a wheeler vise block to put things together, but probably want something better for barrel nut torquing. a MI receiver rod is best, but plastix revolution vise blocks work well too, they clamp both sides in a vise, and are the best way to go for 9mm and 22 stuff that doesn't have locking lugs to engage in the barrel extension. To torque the barrel nut, USE THE CORRECT GREASE, if you do it dry, it can break or shear the pin, if you use something other than Aeroshell or equivalent aluminum safe grease, it can corrode and never come off. Most barrel nuts torque to 30ft/lb, back off, then torque again, then you can go up to 80 to align a gas tube. ALWAYS check instructions with proprietary barrel nuts, some have far less torque, might need to be timed/shimmed for the handguard hardware, or might not.
     

    Mr.Culper

    Active Member
    Jan 16, 2021
    858
    Another question,is one barrel as good as another? what to stay away from?
    Looking at 200-600 yds
     

    Kirkster

    Active Member
    Jan 9, 2009
    329
    Severn, PRoMD
    Another question,is one barrel as good as another? what to stay away from?
    Looking at 200-600 yds

    For 200 to 600 yards most barrels will be fine. I know early on Faxon had some feed ramp issues but the got them fixed. So really it is what does you budget fit in? What are you looking for accuracy wise? What length? Is it a range toy or are you going to hunt with it? Does weight matter?

    Good luck. I built my AR10 in 6.5CM last year and it is in the 1/4 inch moa to 1/2 inch range if I do my job...
     

    Mr.Culper

    Active Member
    Jan 16, 2021
    858
    Thanks,
    I suspected most barrels would do for generic shooting.
    looking for 1/2 - 3/4 at 100,, 3-4" at 500
    Range toy,,, but want portability if called upon, 18-20" barrel

    For 200 to 600 yards most barrels will be fine. I know early on Faxon had some feed ramp issues but the got them fixed. So really it is what does you budget fit in? What are you looking for accuracy wise? What length? Is it a range toy or are you going to hunt with it? Does weight matter?

    Good luck. I built my AR10 in 6.5CM last year and it is in the 1/4 inch moa to 1/2 inch range if I do my job...
     

    alucard0822

    For great Justice
    Oct 29, 2007
    17,643
    PA
    "Real world" accuracy isn't as simple as X-MOA. You have shifts as a barrel heats up, shots in a group, how it does with the best ammo, how it does with cheap ammo, then there is the question if your optic and range is able to get the most out of it. I am very happy with 2MOA, sounds meh, but that is out of a reliable, lightweight 3 gun build, 16" Faxon in an Aero M5 set topped with a PST2 complete for under $2K using cheap 150GR FMJ loads. I can knock plates out to 500 yards with relative ease and pretty quick with it, or blow through a fast stage at close range. Most good 308 barrels will get down to 1MOA with decent match ammo(BA, Faxon, Criterion), but to get under 1MOA consistently in 308 you need to go a bit further and spend a bit more. You need a great heavy barrel, Rainier Ultramatch, Proof Research, Shilen, the upper needs to be lapped, and the extension bedded with green loc-tite, the headspacing and bolt face need to be square and snug in-spec. You need a tight fitting receiver set with properly sized pins, a good trigger and stable stock, all topped with an optic that can help you see the difference all the other stuff could make. Even then they can be relatively ammo sensistive, you might need to play around with loads and bullet weight/brand till you find the best combination, but the AR10/AR308 platform is capable.
     

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