Bushmaster Xm15 Instruction Manual

FRONT
SIGHT
DETENT
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LU BR IC A TIO N -  U pper R eceiv er…
L ig htly  lu bric ate  th e  in sid e o f  u pper  re ce iv e r,  th e 
b ore  a nd ch am ber  (u sin g th e cle a nin g ro d a nd a  
p atc h ),  th e o ute r  s u rfa ce s o f  b arre l  a nd fr o n t  s ig ht, 
a nd s u rfa ce s u nde r th e h and guard .  B e s u re  y o u lu be 
i n  a nd a ro u nd a ll  th e L ockin g L ugs ( s e e illu str a tio n a t  r ig ht) .
  D epre ss th e F ro nt  S ig ht  D ete n t  a nd a pply  tw o o r  th re...

21
Note : R eco rd  h ow  fa r y o u m ove  th e r e ar s ig ht  s o  it   c a n b e r e tu rn ed to  it s  o rig in al  p osit io n u pon 
t h e c o m ple tio n o f  th is  ta sk.
R ear  S ig ht
1.)  E le va tio n k n ob
2.)  E le va tio n s cre w  s h aft
3 .)  W in dage k n ob
4.)  W in dage s cre w
5.)  D ete nt h ole s
E le vatio n S cre w  S haft:  A ls o  lu be fr o m  in sid e 
t h e u pper r e ce iv e r a s fo llo w s:
1 .)  T urn  u pper r e ce iv e r u psid e d ow n
2.)  R em ove  c h arg in g...

23
REASSEMBLY (continued)…
3.) Push in Extractor Pin.
4.) Slide Bolt into Carrier.
STAGGER THE GAS RING GAPS
TO REDUCE GAS LOSS. Position the three
ring gaps 120  apart around the bolt.
24
REASSEMBLY (continued)…
5.) Replace Bolt Cam Pin.
GIVE
CAM PIN
A 1/4 TURN
AFTER
INSERTION
6.) Drop in and seat
      the Firing Pin.
FIRING PIN
7.) Pull Bolt out.
WARNING: Be sure the Cam Pin is installed in the Bolt Group. If it isnt, your r\
ifle can still fire 
and will explode!
NOTE: The Bolt is machined so as to...

25
REASSEMBLY (continued)…
8.) Replace Firing Pin Retaining Pin.
9.) Engage, then push Charging Handle part way.
10.) Position Carrier Key in slotted bottom of
Charging Handle. Slide in Bolt Carrier Group.
NOTE: Firing Pin should not fall out when
Bolt Carrier Group is turned upside down.
CAUTION:  Bushmaster does not recommend the practice of swapping bolts between
different rifles. Doing so could result in damage, personal injury or de\
ath.
26
CAUTION: Selector Lever should be on SAFE...

28
MAGAZINE DISASSEMBLY / REASSEMBLY …
1.) Release Base Catch by
     prying up gently on the
     Magazine Floor Plate
     (just enough to clear).
3.) Jiggle Spring and Follower to remove. Do
     not remove the Follower from the Spring.
TO CLEAN and LUBRICATE, Wipe dirt from
Magazine Body, Spring, and Follower. Then 
lightly lubricate the Spring.REASSEMBLY  is reverse of steps above.
Make sure to slide the base under all four 
tabs until it snaps back under the catch.
2.) Remove Magazine Floor Plate...

29
30
PREVENTATIVE MAINTENANCE CHECKS & SERVICES…
CHECK BEFORE YOU FIRE! …
1.) Check to see that there is no excessive oil in the Bore. If there i\
s, swab it out with a patch and
the cleaning rod.
2.) Retract the Bolt to 
ensure free movement 
between Bolt Carrier 
and Gas Tube.
3.) Perform Safety Function Check to ensure that 
Safety Selector Lever works properly.
4.) Check to ensure that the Magazine is secure.
SAFETY FUNCTION CHECK…
UNLOAD RIFLE - REMOVE MAGAZINE - CHECK CHAMBER
See Safety Check next...

31
32
ADJUSTABLE FRONT SIGHT POST…
A2 DUAL APERTURE REAR SIGHT…
(See Page 36 for A1 Sight information)
The Front Sight Post is moved up and down when  “Zeroing ” the Rear Sight.
Once the Rear Sight is zeroed, the Front Sight Post should not be moved.\
LOADING A MAGAZINE …
SH O RT R ANG E -  T his  “la rg er”  a pertu re  is  
u se d fo r  0  -  2 00 m ete rs   ra nge.  A s  sh ow n 
a bove ,  th e s ig ht  is  s e t  to r 0  -  2 00 m ete rs .  T his  
l a rg er  a pertu re  is   o nly   u se d w hen th...

34
ZEROING ADJUSTMENTS (continued)…
*A II th e a bove  v a lu es h ave  b een r o un ded o ff .
T o re m em ber  y o ur  c o rre ct  z e ro  w in dage ,  n ote  lo ca tio n o f  W in dage S ca le  a nd W in dage K nob 
WINDAGE KNOB
POINTERIMPACT0.3 cm (1/8 in.)1.25 cm (1/2 in.)2.50 cm (1 in.)
3.8 cm (1 1/2 in.)5.0 cm (2 in.)6.3 cm (21/2 in.)7.6 cm (3 in.)8.8 cm (3 1/2 in.)10.0 cm (4 in.)
FOR WINDAGE KNOB  (per click)*…
DISTANCE25 meters100 meters200 meters300 meters400 meters500 meters600 meters700...

25 METER ZEROING PROCEDURES (continued)…4.)  N ow  r o ta te  th e e le va tio n k n o b  u p o ne c lic k p ast  th e 3 00-m ete r m ark .  F ro m  th is  p oin t  o n,  th e 
e le va tio n k n ob  s h ould  n ot  b e m ove d.  A ny c h an g es in  e le va tio n re quir e d in  th e fo ll o w in g z e ro in g 
s te ps a re  m ad e to  t h e f r o nt s ig ht p ost o nly .
5 .)  C are fu lly  a im  a nd fir e  a t th e  c e nte r o f th e  ta rg et b ulls -e ye .
6.)  If  y o ur s h ot  g ro up is  n ot...

A1 SIGHTS - DIFFERENCES & ADJUSTMENTS (continued)…
NO TE : T o z e ro  th e r if le ,  a dju st  th e  fr o nt  s ig ht  ( e le va tio n) a nd th e r e a r s ig ht  ( w in dage ) s o  th at  y o u 
c a n h it  th e a im in g p o in t  a t a  g iv e n r a nge.
F R O NT S IG HT -  T o  adju st  ele va tio n,  depre ss   de te nt  and   ro ta te   post  as 
d escrib ed p re vio usly  fo r  A 2 F ro nt  S ig h t  P ost.   T he  5  n otc h es o f  th e A 1 p ost 
a llo w  fo r  a  fin er  a dju stm en t  th...