Tech information listing

#1

This list of information and tech specs came from ArmaLite and was last update in December 0f 2013. All information in this list mostly pertains to ArmaLite rifles, but crosses over to other “AR” style of rifles weather it being a 5.56/.223 or 7.62/.308.

BARRELS
· AR-10 barrels are 4140 steel, chrome lined, button cut, and double lapped.
· Eagle Arms standard barrels are chrome-moly, button cut, and double lapped.
· M-15 barrels are 4150 steel, CMV (Chrome Moly Vanadium) MIL-B-11595-E (military spec) chrome lined, button cut, and double lapped.
· All Stainless Steel barrels use AISI 416R stainless steel, button cut, and triple lapped.
· Chrome lined and chrome moly barrels .750 at the journal (under the gas block).

· Stainless steel barrels .875 at the journal (under the gas block).
· All AR-10 barrels are NATO chambered and will accept 7.62 X 51 and .308 Winchester ammo.
· M-15 stainless steel barrels (Wylde chamber) and chrome lined barrels (NATO chamber) will accept 5.56 X 45 and .223 Remington ammo.
· All chrome-lined barrels are made from SAE 4140 or SAE 4150 steel and receive manganese phosphate per 5.3.1.2 of MIL-STD-171.

BARREL EXTENSIONS
· Threads on barrel extensions - (.223) 1-3/16 X 16 - (.308) 1 X 16.
· Distance between barrel extensions and locking lugs - (.223) .497 +/- .005 - (.308) .610 +/- .005

UPPER and LOWER RECEIVERS
· AR-10 uppers use 7175-T74 aluminum (forged) and lowers use 7175-T73 aluminum (forged).
· M-15 uppers use 7075-T6 aluminum (forged) and lowers use 7075-T6 aluminum (forged).
· All AR-10 and M-15 upper and lower receivers’ exterior: Hard coat anodized per MIL-A-8625, type 3, class 2, film thickness .0010+/- .0002, finish shall be lusterless (flat) color black # 37038 of Fed-Std-595, seal, grit blast prior to applying finish.

ASSORTED PINS
· AR-10 and M-15 hammer and trigger pins have an OD of .154.
· M-15 pivot (.9” long) and takedown (1.14”) pins have an OD of .248 -.250.
· AR-10 pivot (1.18”) and takedown pins (1.36”) have an OD of .2745 - .2755.
· NM oversized pivot and takedown pins for M-15’s have an OD of .250 - .251.
· NM oversized pivot and takedown pins for AR-10’s have an OD of .277 - .291.
· AR-10 cam pin - .375 OD pin, .400 X .500 head. Doesn’t rotate within bolt carrier.
· M-15 cam pin - .310 OD pin, .317 X .400 head. Rotates within bolt carrier.

BOLT CARRIERS
· AR-10 and M-15 bolt carriers are chrome lined on the inside (not the outside).
· AR-10 and M-15 gas keys are chrome lined.
· AR-10 bolts and carriers use 8620 steel.
· M-15 bolts use 158 Carpenter steel and carriers use 8620 steel.
· AR-10 and M-15 bolts and carriers are shot peened and grip blast finished.

SIGHTS
· EX3406 MWI Universal Flip Up Rear Sight – dual aperture dimensions .200 / .070.
· NM M-15 rear sight – 1/4 MOA windage and 1/2 MOA elevation (integrated carry handle).
· NM M-15 rear sight – 1/4 MOA windage and 1/2 MOA elevation (detachable carry handle).
· NM AR-10 rear sight – 1/4 MOA windage and 1/4 MOA elevation (detachable carry handle).
· All standard AR-10 and M-15 rear sights – 1/2 MOA windage and 1 MOA elevation.
· All AR-10 and M-15 front sight posts have 4 detents per revolution. 1/4 turn up or down = 1 MOA
· Jones sight kit (15806200) NM hooded sight parts kit apertures (# 2) .042, (# 3) .046, (# 4) .051, and (# 5) .055.
· AR-10/M-15 front sight post height (base to tip) - .280
· AR-10/M-15 standard rear battle sight dual apertures .70 / .195
· AR-10/M-15 NM ramped front sight posts of .05, .06, and .07 (AR-10 receives 2 sets of these).

GAS BLOCKS
· M-15 top of gas block and upper receiver rail – top of gas block is .293 (+/- .010) lower than top of upper receiver.
· AR-10 top of gas block and upper receiver rail – top of gas block is .398 (+/- .010) lower than top of upper receiver.
· M-15 CMV chrome lined and NM SST barrel journal .750, 15T SST barrel journal .875
· AR-10 chrome lined and SST 10T carbine barrel journal .750, all other SST barrel journals are .875
· AR-10 Super SASS adjustable gas block length - .900. Journal is .875.
· AR-10 / M-15 Gas Block Shim Spacer - .750 ID, .850 OD, .030 thick.

MAG SPRINGS
· Magazine springs for the AR-10, M-15, and AR-30 – stainless steel, type 17-7 pre-hardened ASTM A313.

SCOPE MOUNTS
· 1” = 25.4MM
· 30MM = 1.18”
Medium height - 1” and 30MM = 1.250” from top of upper receiver to center of scope rings (up to 50MM objective).
High height - 1” and 30MM = 1.450” from top of upper receiver to center of scope rings (up to 60MM objective).
7/64” Allen wrench for scope ring screws.

RECEIVER EXTENSION TUBES
Receiver extension tubes use 6061-T6 extruded aluminum.
· .223 / .308 rifle length 9-11/16” (inside depth)
· .223 carbine length 6-15/16” (inside depth)
· .308 carbine length 7-5/8” (inside depth)

   Commercial size tube O.D. - 1.165” – 1.167” (we don’t use this anymore) 
  Military (G.I.) size tube O.D. – 1.145” – 1.147” (carbine and rifle) 
  Thread size 1-3/16 X 16

BUFFER SPRINGS
· .308 buffer spring rifle and carbine length 14-1/8”
· .223 buffer spring rifle length 13-1/2” max – 11-3/4” min
· .223 buffer spring carbine length 11-1/4” max – 10-1/16” min

BUFFERS
· .223 rifle length 5-7/8” – weight 5.2 oz
· .308 rifle length 5-3/16” – weight 5.4 oz
· .223 carbine length 3-1/4” – weight 3.0 oz
· .308 carbine length 3-1/4” – weight 5.4 oz

TORQUE SPECS
· Bolt carrier gas key screws – 55 inch lbs
· Barrel nut .223 – 35-65 ft lbs
· Barrel nut .308 – 45-85 ft lbs
· Barrel extensions .223 / .308 – 150 ft lbs
· Receiver extension tube rifle – 35-39 inch lbs
· Receiver extension tube carbine – 40 (+/- 2”) inch lbs and stake
· Flash suppressor – 15-20 ft lbs

· Gas blocks and A2 front sight bases – 65 inch lbs
· SPR Mod 1 Barrel nut – 50-60 ft lbs

BARREL THREAD SIZE (FLASH SUPPRESSORS AND MUZZLE BRAKES)
· .223 / M-15 and 180B– 1/2”-28
· M-15 – 7.62 X 39 and 6.8 – 5/8”-24
· .308 / AR-10 – 5/8”-24
· .308, .300, and .338 / AR-30 – 5/8”-18 UNF-3A
· .300 AR-30A1 – 5/8”-24 / .338 AR-30A1 – 3/4”-24

· .308 AR-31 – 5/8”-24
· 50BMG & .416 Barrett / 50A1 – 1”-14 UNS-3B

AR-10 CRUSH WASHER – M-15 PEEL WASHER
· AR-10 crush washer – 1/8” thick – 5/8” ID – 7/8” OD
· M-15 peel washer – 1/16” thick – 1/2" ID – 5/8” OD

TRIGGER WEIGHTS FROM FACTORY
· Tactical two stage – 1st stage 3.5 lbs – 2nd stage 5-6 lbs (MIM – Metal Injected Molded)
· NM two stage – 1st stage 2.5 lbs – 2nd stage 4.5-5 lbs (MIM – Metal Injected Molded)
· Standard military trigger – 5.5-9.5 lbs (Cast)
· Schilen single stage trigger (AR-50/AR-50A1 – AR-30/AR-30A1/AR-31) 4.5 lbs approximate
Note: All triggers were cast until March of 2009. Only the single stage trigger is cast now.

LENGTH OF PULL
· AR-10 carbine (collapsed) – 11-1/8” - (extended) – 14-1/2”
· M-15 carbine (collapsed) – 10-3/8” - (extended) – 14-1/2”
· AR-10 rifle – 14-1/2”
· M-15 rifle – 14-1/2”
· AR-30 – (all) 13-1/2”
· AR-30A1 – (standard) 13.5” (target) – 13.6 - 15.6
· AR-31 – (target) 13.6 – 15.6
· AR-50 - (all) 14.9”

DETACHABLE FRONT SIGHT HEIGHT
· E20151 M-15 detachable front sight – 1.395” height
· EA5045 AR-10 detachable front sight – 1.531” height

GAS TUBE LENGTH
· M-15 rifle – 15-3/16”
· M-15 mid length carbine – 11-3/4”
· M-15 shorty carbine – 9-3/4”
· AR-10 rifle – 15-1/2”
· AR-10 mid length carbine – 12-1/16”
· All gas tubes: .180 OD and .117 ID

THREAD SIZE FOR UPPER RECEIVERS FOR BARREL NUTS
· M-15 – 1-1/4” X 18 UNF-3A
· AR-10 – 1-7/16” X 18 UNEF-3A
* UNF = Unified Fine thread. UNEF = Unified Extra Fine thread.

DISTANCE FROM BORE CENTERLINE TO TOP OF PICATINNY RAIL OF UPPER RECEIVER
· M-15 – 1.213”
· AR-10 – 1.318”

GO GAGE CHAMBER SPEC INFORMATION (TOLERANCES FOR GOOD-TO-GO CHAMBERS)
· AR-10 NATO – 1.633-1.638 (stainless steel, chrome moly, and chrome lined barrels)
· M-15 NATO – 1.465-1.468 (chrome moly and chrome moly vanadium/chrome lined barrels)
· M-15 WYLDE – 1.464-1.467 (stainless steel barrels)

MCFARLAND GAS RING ACCEPTABLE OD DIMENSIONS
· M-15 = .499 - .501
· AR-10 = .656 - .659

  Note: There is no acceptable or unacceptable M-15 single gas ring OD dimensions as they flex within the bolt.

M-15 AND AR-10 PORT DOOR ROD LENGTHS
· M-15 (All) 3-7/8” long
· AR-10 (Standard) 4-1/16” long
· AR-10 (“T”) – 4-3/16” long – used also on any AR-10 that uses a free floated handguard

SUGGESTED (GRAIN) AMMO FOR ALL FIREARMS, BARREL TWIST & GROOVE
· M-15 (16” and 20”) CMV chrome lined barrels – 52-69 grain – 1:9 RH - 6 groove
· M-15 (20”) SST barrels – 69-80 grain – 1:8 RH - 6 groove
· M-15 (16”) 6.8 SPC II CMV chrome lined barrels – 110-115 grain – 1:11 RH - 4 groove
· M-15 (16”) 7.62X39 CMV chrome lined barrels (bore .311) – 123 grain – 1:10 RH - 4 groove
· M-15 SPR Mod 1 (16”) (shorty 6” gas system) CMV chromed lined barrels – 69-80 grain – 1:7 RH - 6 groove
· M-15 SPR Mod 1 (16”) (mid-length 8” gas system) CMV chrome lined barrels – 52-69 grain – 1:9 RH - 6 groove
· M-15 (16”) .22LR – CMV chrome lined barrels – 1:16 – 5 groove
· AR-10 (16” and 20”) chrome lined barrels – 150-175 grain – 1:11.25 RH - 6 groove
· AR-10 (20”) .243 chrome moly barrels – 90-100 grain – 1: 10 RH - 6 groove
· AR-10 (22”) .260 SST barrels – 120-140 grain (139 and 140 grain functioned best) – 1:8 RH - 6 groove
· AR-10T (16” & 20”) SST barrels – 150-185 grain – 1:10 RH - 6 groove
· AR-10 (20”) SuperSASS SST barrels – 150-185 grain – 1:10 RH - 6 groove
· AR-10 (20”) NM SST barrels – 168-185 grain - (Will stabilize 200 grain ammo) – 1:10 RH - 4 groove
· AR-10 (22”) .338 Federal SST barrels – 185-200 grain (Max 225 grain ammo) – 1:10 RH - 6 groove

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#2

This is great information, thanks for sharing it.

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#4

I think I put it in the wrong category.

I meant to put it in “Gunsmithing” and not the “Help it broke”

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#5

mrr

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#6

I believe you can move posts yourself, should be covered here…

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#7

Great post, thanks for sharing.

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