ar - 15 variants 

Statements about this table:
the barrel length of 11.5 in have a barrel twist of 1:7
colt model no
stock
fire control
rear sight
forward assist
le1020
4th generation
s - 1
flattop
yes
le1033
4th generation
s - 1
flattop
yes
le6920
4th generation
s - 1
flattop
yes
le6920hb
4th generation
s - 1
flattop
yes
le6921
4th generation
s - 1
flattop
yes
le6921cqb
4th generation
s - 1
flattop
yes
le6921hb
4th generation
s - 1
flattop
yes
le6921sp
4th generation
s - 1
flattop
yes
le6933
4th generation
s - 1
flattop
yes
le6940
4th generation
s - 1
flattop
yes
le6941
4th generation
s - 1
flattop
yes
colt model no
barrel length
barrel profile
barrel twist
le1020
16 in
m4
1:7
le1033
11.5 in
a2
1:7
le6920
16 in
m4
1:7
le6920hb
16 in
m4 hbar
1:7
le6921
14.5 in
m4
1:7
le6921cqb
10.5 in
m4 hbar
1:7
le6921hb
14.5 in
m4 hbar
1:7
le6921sp
10 in
m4 hbar
1:7
le6933
11.5 in
a2
1:7
le6940
16 in
m4
1:7
le6941
16 in
m4
1:7
colt model no
hand guards
bayonet lug
muzzle device
le1020
rail system
yes
a2
le1033
rail system
yes
a2
le6920
m4
yes
a2
le6920hb
m4
yes
a2
le6921
m4
yes
a2
le6921cqb
m4
yes
a2
le6921hb
m4
yes
a2
le6921sp
m4
yes
a2
le6933
short ribbed
yes
a2
le6940
monolithic rail system
yes
a2
le6941
rail system
yes
a2