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Quib
17 October 2009, 08:26
http://quib.weaponevolution.com/FAQ Intro.png

http://quib.weaponevolution.com/FAQSafety.png



PAGE ONE


CARRIER KEY-GAS TUBE INTERFERENCE CHECK
GAS RING SERVICEABILITY CHECK
BUFFER SPRING LENGTH INSPECTION
BARREL INDEXING AND FSB CANTING
DENTED PRIMER….OK?
CANTED REAR SIGHT ASSEMBLY
FRONT SIGHT BASE GAS LEAKAGE
UPPER RECEIVER INTERIOR FINISH
GAS TUBE CLEANING
30RD MAGAZINE WILL NOT LOCK
PICATINNY RAIL T-MARKINGS
TRIGGER PIN WALKING
THE AR15 & COMPONENT STAKING
AR15 ROLL PIN CHART




PAGE TWO


AR15 TORQUE VALUES
BROKEN TRIGGER GUARD EAR
A2 PISTOL GRIP SCREW SPEC'S
CUT CARRY HANDLE BUS
BUFFER RATTLE
MIL VERSES CIV CLEANING ACCESSORIES
GAS TUBE REMOVAL
OPTIC CO-WITNESS
CONVERTING THE GI CLEANING ROD HANDLE FOR CHAMBER CLEANING
APPLYING SLIPPAGE MARKS

Quib
17 October 2009, 08:29
http://quib.weaponevolution.com/Carrier Gas Key Inter Page.png

CARRIER KEY-GAS TUBE INTERFERENCE CHECK

http://img.photobucket.com/albums/v489/Metroliner/CarrierKeyGasTubeCheck.jpg

http://img.photobucket.com/albums/v489/Metroliner/CarrierKeyGasTubeCheck1.jpg

http://img.photobucket.com/albums/v489/Metroliner/CarrierKeyGasTubeCheck2.jpg


ADJUSTING THE CARRIER KEY TO GAS TUBE FIT


http://img.photobucket.com/albums/v489/Metroliner/GasTubeAdj1.jpg

http://img.photobucket.com/albums/v489/Metroliner/GasTubeAdj.jpg

http://img.photobucket.com/albums/v489/Metroliner/GasTubeAdj2.jpg

http://img.photobucket.com/albums/v489/Metroliner/GasTubeAdj3.jpg



Below are examples of gas tube wear.



http://img.photobucket.com/albums/v489/Metroliner/GasTube2-vert.jpg

Quib
17 October 2009, 09:24
http://quib.weaponevolution.com/Gas Ring Page.png

http://img.photobucket.com/albums/v489/Metroliner/BoltRingWear.jpg

NOTE: A word on performing of the Gas Ring Serviceability Check

There seems to be an alternate method of performing the Gas Ring Serviceability Check, a method I see quite often referred to on the various AR15 discussion boards.

This alternate method involves standing the cleaned and stripped bolt and carrier on a flat surface such as a table top, and observing if the bolt carrier collapses onto the bolt under the weight of the carrier.

While I have spoken to very knowledgeable individuals who have attended industry sponsored AR15 Armorers Courses where this method was instructed, I have yet to find this alternate method published in any manufacturers maintenance publication.

My personal view on the alternate method:

It should provide the same results as the published method, but may result in changing the gas rings a bit earlier than that of the published method. This simply being, the carrier is heavier than the bolt and will most likely collapse sooner onto the bolt verses the bolt falling free from the carrier when suspended.

Quib
19 October 2009, 18:39
http://quib.weaponevolution.com/Buffer Spring Page.png

BUFFER SPRING LENGTH INSPECTION

http://img.photobucket.com/albums/v489/Metroliner/BufferSpringInsp.jpg

Quib
28 October 2009, 04:29
http://quib.weaponevolution.com/Rear Sight Windage Page.png

BARREL INDEXING AND FSB CANTING

http://img.photobucket.com/albums/v489/Metroliner/cant2-200910282.jpg

http://img.photobucket.com/albums/v489/Metroliner/cant5-200910282.jpg

Quib
15 November 2009, 14:52
http://quib.weaponevolution.com/Dented Primer Page.png

http://quib.weaponevolution.com/Spikes Review/Dented Primer.png

Quib
14 March 2010, 11:08
http://quib.weaponevolution.com/Rear Sight Page One.png

ArmaLite addresses this frequently asked question with their Technical Note 18: M16A2 Rear Sights

http://quib.weaponevolution.com/Assorted/Tech Note.png

http://www.armalite.com/

Quib
21 March 2010, 08:54
http://quib.weaponevolution.com/Front Sight Base Leakage 1.png

http://quib.weaponevolution.com/FSB Gas Leakage 2.png

Quib
27 March 2010, 11:13
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http://quib.weaponevolution.com/DFL Interior Shot (2).png

Quib
27 March 2010, 11:15
http://quib.weaponevolution.com/Gas Tube Page.png

http://quib.weaponevolution.com/Gas Tube Cleaning 2.png

Quib
20 April 2010, 19:59
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http://quib.weaponevolution.com/GI 30rd.png

http://quib.weaponevolution.com/MP 30rd.png

Quib
5 May 2010, 18:41
http://quib.weaponevolution.com/T-markings Page.png

http://quib.weaponevolution.com/T-Markings Page.png

Quib
21 May 2010, 08:27
http://quib.weaponevolution.com/Trigger Pin Walking.png


A Trigger Pin that vibrates out of the lower receiver during firing, is often times referred to as a “Walking Trigger Pin”. “Walking Trigger Pins” are usually the result of two common mistakes made by those new to assembling their own lower receivers involving installation of the FCG (Fire Control Group).



Problem Number One: Hammer Spring Leg Placement

Often times the assembler mistakenly places the legs of the hammer spring under the trigger pin, against the bottom of the FCG pocket of the lower receiver along the sides of the trigger assembly. Taking a look at the diagram below, we see that the hammer spring legs actually ride on top of the trigger pin.

The pins utilized for the trigger and hammer, are designed with two circumferential grooves, one groove outboard and one center. When a pin is utilized in the trigger position, it is retained within the lower receiver by the tension of one of the hammer spring legs riding within the outermost groove of the pin. (See View A of the illustration below.)

If the hammer spring legs are not placed on top of the trigger pin, with one leg placed in the outermost trigger pin groove, the firer may experience a “Walking Trigger Pin”.



Problem Number Two: Incorrect Hammer Spring Installation

Occasionally lower receiver parts kits (LPK) arrive with the hammer and hammer spring separated from each other. If not following the maintenance manual, or detailed assembly instructions, incorrect installation of the hammer spring by the assembler is often times the result. Or, there was a mistake during assembly of the two by the distributor or Mfr., resulting in incorrect installation of the hammer spring.

Taking a look at the illustration below (Position Of The Hammer Spring Legs), we see the correct installation of the hammer spring on the hammer itself. Incorrect installation of the hammer spring on the hammer, can lead to incorrect pressure applied to the trigger pin by the tails of the hammer spring, most critical being the spring tail riding in the trigger pin groove.

This lack of proper spring tail pressure, can often times lead to a “Walking Trigger Pin”.


A not too common problem, but one which I have personally experienced which can lead to a “Walking Trigger Pin”, was caused by the grooves not being cut deep enough in the trigger pin to sufficiently hold the tail of the hammer spring.

In this instance, I had to resort to opening up of the groove, using a small jewelers rat tail file. This was a temporary fix. Removal and replacement of the trigger pin with an in-spec trigger pin would be highly recommended.



http://quib.weaponevolution.com/Trigger Pin One.png

Quib
19 June 2010, 12:56
http://quib.weaponevolution.com/Stake Page.png


Definition: Staking is the physical displacement of material into a fastener (screw head, bolt head, ect) in order to prevent backing out or rotation of the fastener resulting in loosening.

The AR15 has two components where staking is beneficial:

- The Bolt Carrier Gas Key
- Carbine Receiver Extension Castle Nut


The Bolt Carrier Gas Key

Below is a cross-sectional view of the Bolt Carrier Gas Key before installation and staking of the Gas Key screw.


http://quib.weaponevolution.com/Stake3.png



Below is a cross-sectional view of the Bolt Carrier Gas Key after installation and staking of the Gas Key screw. Make note of the Carrier Gas Key material displaced against each side of the Gas Key screw head. Serrations in the head of the screw also help grab and hold the Carrier Gas Key material displaced against it.



http://quib.weaponevolution.com/Stake1.png



Bolt Carrier Gas Key after staking.



http://quib.weaponevolution.com/Stake4.png




Carbine Receiver Extension Castle Nut Staking

Below is an example of the Carbine Receiver Extension Castle Nut after staking. In the process of staking the Carbine Receiver Extension Castle Nut, Receiver End Plate material is displaced into the Castle Nut. This prevents rotation of the Castle Nut which would result in a loose Receiver Extension and Stock.


http://quib.weaponevolution.com/Stake5.png

Quib
19 June 2010, 12:58
http://quib.weaponevolution.com/Roll Pin Page.png


AR15 ROLL PIN CHART*



A2 WINDAGE KNOB ROLL PIN

PN: MS16562-103
OAL: 0.673 INCHES MIN AND 0.703 INCHES MAX
DIA: 0.066 INCHES MIN AND 0.069 INCHES MAX


BOLT EJECTOR ROLL PIN

PN: MS16562-98
OAL: 0.360 INCHES MIN AND 0.390 INCHES MAX
DIA: 0.066 INCHES MIN AND 0.069 INCHES MAX


CHARGING HANDLE LATCH ROLL PIN / FORWARD ASSIST ASSY PAWL ROLL PIN

PN: 8448521-2
OAL: 0.257 INCHES MIN AND 0.277 INCHES MAX
DIA: 0.066 INCHES MIN AND 0.069 INCHES MAX


GAS TUBE ROLL PIN

PN: MS16562-106
OAL: 0.297 INCHES MIN AND 0.327 INCHES MAX
DIA: 0.083 INCHES MIN AND 0.086 INCHES MAX


SIDE SLING BARREL MOUNT ROLL PINS

PN: MS39086-93
OAL: 0.678 INCHES MIN AND 0.698 INCHES MAX
DIA: 0.125 INCHES NOMINAL


FORWARD ASSIST ROLL PIN

PN: MS16562-121
OAL: 0.610 INCHES MIN AND 0.640 INCHES MAX
DIA: 0.099 INCHES MIN AND 0.103 INCHES MAX


BOLT CATCH ROLL PIN

PN: MS16562-119
OAL: 0.485 INCHES MIN AND 0.515 INCHES MAX
DIA: 0.099 INCHES MIN AND 0.103 INCHES MAX


CARBINE STOCK LATCH NUT ROLL PIN

PN: MS16562-202
OAL: 0.423 INCHES MIN AND 0.453 INCHES MAX
DIA: 0.083 INCHES MINI AND 0.086 INCHES MAX


STANDARD ISSUE TRIGGER GUARD ROLL PIN

PN: MS16562-129
OAL: 0.610 INCHES MIN AND 0.640 INCHES MAX
DIA: 0.131 INCHES MIN AND 0.135 INCHES MAX



http://farm5.static.flickr.com/4102/4758454843_f050e1d2f4_b.jpg


* Part Numbers are from the current Army TM 9-1005-319-23&P W/C #8.

Quib
20 June 2010, 10:22
http://quib.weaponevolution.com/AR15 Torque Page.png




AR15 Torque Value Chart*


-Carrier Key Screws: 50-58 in/lbs

-Barrel Nut: 30-80 ft/lbs

-Receiver Extension (Rifle): 35-39 ft/lbs

-Receiver Extension Castle Nut (Carbine): 38-42 ft/lbs



* Torques are from the current Army TM 9-1005-319-23&P W/C #8.

Quib
4 July 2010, 10:51
http://quib.weaponevolution.com/Trigger Guard Page.jpg

http://quib.weaponevolution.com/Trigger Guard 1.JPG

http://quib.weaponevolution.com/Trigger Guard 2.JPG

Quib
20 July 2010, 16:16
http://quib.weaponevolution.com/Pistol Grip Screw.png



The threads are 1/4-28.

The basic specs of the original GI A2 grip screw are......

SCREW, MACHINE, RIFLE GRIP
NSN: 5305-01-268-1191
Part Number: AN501D416-18

THREAD SERIES DESIGNATOR: UNF
NOMINAL THREAD DIAMETER: 0.250 INCHES
THREAD QUANTITY PER INCH: 28
THREAD LENGTH: 0.992 INCHES MIN AND 1.125 INCHES MAX
FASTENER LENGTH: 1.063 INCHES MIN AND 1.125 INCHES MAX
INTERNAL DRIVE STYLE: B10 SLOT
HEAD STYLE: A33 FILLISTER




http://quib.weaponevolution.com/Wrong Grip Screw.jpg

Quib
15 August 2010, 20:50
http://quib.weaponevolution.com/CCH BUIS FAQ.png



With little effort and basic mechanical skill, the detachable carry handle/rear sight assembly can quickly be turned into a robust fixed rear sight assembly similar in design to the LMT Rear Sight.




http://quib.weaponevolution.com/CCH BUIS 1.JPG



Prep the carry handle for work as follows:



Remove thumb nuts. Some carry handles come with swaged cross-bars to prevent the thumb nuts from being completely backed off and lost. If enough force is used to turn the nut, the swage can be overcome and the nuts completely removed.



Remove locking bar. Set aside. The locking bar will later be trimmed to fit and reinstalled.



Use a hammer to tap out the cross-bars. Removing the cross-bars is not a necessary step, but I feel their removal helps in securing the carry handle while it is in work.


Using a hacksaw, bandsaw or Dremel Tool with cut-off wheel to cut the carry handle, carefully draw out the cut lines as illustrated below. Leave enough extra material to allow for shaping and contouring. The CCH BUS you see in these photos, was secured in a bench vice and cut with a hacksaw.





http://quib.weaponevolution.com/CCH BUIS 3.JPG

http://quib.weaponevolution.com/CCH1.jpg




For shaping and contouring, a sanding disc in an electric drill was used to form the rounded ears of the BUS, giving it a similar profile to that of the LMT Rear Sight. A combination of jewelers files and fine sandpaper was then used to finish up the final shaping, smoothing and contouring of the cut edges.

The locking bar was then placed temporarily on the BUS, and a position was determined for the necessary cut-line. The locking bar was then secured in a bench vice and cut with a hacksaw. Final shaping and contouring was accomplished with jewelers files. The cut exposed steel edge was then degreased with non-chlorinated brake cleaner and touched up with G96 Liquid Cold Blue applied with a q-tip.

Link: http://http://www.g96.com/Gun_Blue.html (http://www.g96.com/Gun_Blue.html)

The exposed bare aluminum of the CCH BUS was then degreased with non-chlorinated brake cleaner and touched up with Birchwood Casey Aluminum Black. This process of degreasing and applying Aluminum Black was repeated until a uniform finish was achieved, almost matching perfectly with the remainder of the CCH BUS’s black anodized finish.

Link: http://http://sport.birchwoodcasey.com/Finishing/FinishingDetails.aspx?ProductID=0790cc91-b2e8-488d-a6fa-8820790beefb (http://sport.birchwoodcasey.com/Finishing/FinishingDetails.aspx?ProductID=0790cc91-b2e8-488d-a6fa-8820790beefb)

One of the many spray-on gun finishes available may be substituted in lieu of the Birchwood Casey Aluminum Black.

Reassemble the CCH BUS by tapping in the cross-bar, seating it fully into the serrations cut from the initial factory assembly. Reinstall the cut and refinished section of locking bar and spin-on the thumb nut.



__________________________________________________ _______________________________________________


Thumb-Nut Mod:

To eliminate the bulkiness and trim some weight from the CCH BUS, I cut down the cross-bar and installed an AN960 aircraft washer with an MS21042 self-locking nut. If this modification is desired, AN/MS Spec aircraft hardware might be available online through an aircraft parts vendor, or similar hardware can be purchased at the local hardware store.



http://quib.weaponevolution.com/MS21042.jpg


http://quib.weaponevolution.com/CCH BUIS 4.JPG



http://quib.weaponevolution.com/CCH BUIS 5.JPG

Quib
17 October 2010, 09:21
http://quib.weaponevolution.com/Buffer Rattle FAQ.png

http://quib.weaponevolution.com/Buffer 2.JPG

Quib
21 November 2010, 12:08
http://quib.weaponevolution.com/Cleaning 1.png

http://quib.weaponevolution.com/Cleaning 2.jpg

http://quib.weaponevolution.com/Cleaning 3.JPG

http://quib.weaponevolution.com/Cleaning 4.jpg

http://quib.weaponevolution.com/Cleaning 5.JPG

http://quib.weaponevolution.com/Cleaning 6.jpg

Quib
25 November 2010, 15:16
http://quib.weaponevolution.com/Gas Tube FAQ.png


Gas tube removal on a weapon that has been in service can sometimes present a challenge. Carbon build-up forming between the gas tube and interior of the front sight base can keep the gas tube from being removed by hand without the assistance of tools.

One tip I have used with success over the years, is the use of a set of modified Vice Grips to aid in gas tube removal.



http://quib.weaponevolution.com/Gas Tube FAQ 1.jpg


http://quib.weaponevolution.com/Gas Tube FAQ 2.jpg


http://quib.weaponevolution.com/Gas Tube FAQ 3.jpg


http://quib.weaponevolution.com/Gas Tube FAQ 4.jpg

Quib
16 December 2010, 05:05
http://quib.weaponevolution.com/FAQ.png





For an explanation of AR15 optic co-witness, please see Paulo’s tutorial at the following link:


http://www.weaponevolution.com/forum/showthread.php?2497-UNDERSTANDING-CO-WITNESS

Quib
19 December 2010, 07:18
http://quib.weaponevolution.com/FAQ Chamber Brush.png




Keeping the chamber free of carbon build-up is an important part of preventative maintenance (PM). Inserting and spinning the chamber brush can not be accomplished using a standard cleaning rod with spinning handle, such as those designed for cleaning a rifle or pistol bore.

The chamber brush due to design, requires a solid one-piece rod without a spinning handle, to overcome the friction encountered while inserting and turning the chamber brush.




Common problems I’ve seen when attempting to clean the chamber are:

- Using a chamber brush designed for 7.62mm rather than 5.56mm.

If the chamber brush is excessively difficult to insert and spin, do not force it. Remove the brush and verify its dimensions against the drawing below (Fig. 1). New AR owners have accidentally purchased larger 7.62mm chamber brushes designed for the AR10, which are similar in design to the smaller caliber 5.56mm AR15 chamber brush.



http://quib.weaponevolution.com/Chamber Brush dimensions Sm.jpg


Fig. 1


- Attempting to use a cleaning rod with spinning handle.

The chamber brush by design is a tight fit in the chamber. Attached to a rod with spinning handle, there is simply too much brush friction to over come. Purchase a short one piece cleaning rod without a spinning handle, or utilize the GI cleaning kit handle which is designed to convert into a t-handle for cleaning of the chamber (Fig. 2)



http://quib.weaponevolution.com/Chamber Brush THandle.jpg


Fig. 2



- Use adequate lubrication when cleaning the chamber.

A dry chamber brush or a chamber brush with minimal CLP applied, can be difficult to insert and spin. Use adequate lubrication applied directly to the brush bristles or squirted into the chamber itself. This will ease spinning of the brush, and of course help break-up carbon deposits.

- Use a spinning corkscrew motion when inserting the chamber brush.

Do not directly insert the chamber brush, then attempt to spin it. Instead, use a spinning corkscrew motion, simultaneously spinning and inserting the brush in one clockwise motion, as if driving in a screw. Once in the chamber, continue spinning for a few revolutions, then back the brush out of the chamber while continuing to spin it in a clockwise direction. Spinning the chamber brush in a back and forth motion or counter clockwise direction will only loosen the brush.




To convert the GI Cleaning Kit handle into a t-handle for chamber cleaning:

- Rotate the top of the handle around the cleaning rod ball joint towards the cleaning rod.
- Snap the swaged end of the handle down over the flattened portion of the cleaning rod.
- Slide a segment of cleaning rod down through the hole in the opposite end of the handle, forming a t-handle.


http://quib.weaponevolution.com/Handle Sm.jpg

http://quib.weaponevolution.com/GI chamber brush.jpg

Quib
19 December 2010, 11:00
http://www.youtube.com/watch?v=dv0IRvtID9U

Quib
25 December 2010, 11:35
http://quib.weaponevolution.com/Slippage Marks FAQ.jpg

http://quib.weaponevolution.com/Slippage Marks FAQ 1.jpg

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http://quib.weaponevolution.com/Slippage Marks FAQ 4.png

http://quib.weaponevolution.com/Slippage Marks FAQ 5.jpg


AIMPOINT INSTALLATION: ADM AD-68H MOUNT: http://www.weaponevolution.com/forum/showthread.php?2060-AIMPOINT-INSTALLATION-ADM-AD-68H-MOUNT