Sight­ing Sys­tems in Small Arms

Re­search and de­vel­op­ment is be­ing un­der­taken glob­ally to en­hance the reach, im­prove the res­o­lu­tion and re­duce the weight of sights in or­der to pro­vide a bet­ter edge to own side

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Re­search and De­vel­op­ment is be­ing un­der­taken glob­ally to en­hance the reach, im­prove the res­o­lu­tion and re­duce the weight of sights in or­der to pro­vide a bet­ter edge to own side.

ASIGHT IS A DE­VICE used to as­sist align­ing or aim weapons, sur­vey­ing in­stru­ments, or other items by eye. Sights can be a sim­ple set or sys­tem of mark­ers that have to be aligned to­gether as well as aligned with the tar­get (re­ferred to as an iron sights on firearms). They can also be op­ti­cal de­vices that al­low the user to see the im­age of an aligned aim­ing point in the same fo­cus as the tar­get. These in­clude tele­scopic sights and re­flec­tor (or ‘re­flex’) sights. There are also sights that project an aim­ing point onto the tar­get it­self, such as laser sights.

At its sim­plest, a sight is typ­i­cally com­posed of two com­po­nents, front and rear aim­ing pieces that have to be lined up. Such sights can be found on many types of de­vices in­clud­ing weapons, sur­vey­ing and mea­sur­ing in­stru­ments, and nav­i­ga­tional tools. On weapons, these sights are usu­ally formed by rugged metal parts, giv­ing these sights the name ‘iron sights’, a term rel­a­tive to other weapon sights in that they are not op­ti­cal or com­put­ing sights. On many types of weapons they are built-in and may be fixed, ad­justable, or marked for el­e­va­tion, windage, tar­get speed, etc. They also are clas­si­fied in forms of notch (open sight) or aper­ture (closed sight). These types of sights can take con­sid­er­able ex­pe­ri­ence and skill in the user who has to hold a proper eye po­si­tion and si­mul­ta­ne­ously fo­cus on the rear sight, the front sight, a tar­get at dif­fer­ent dis­tances, and align all three planes of fo­cus.

Tele­scopic Sight

A tele­scopic sight, com­monly called a scope, is a sight­ing de­vice that is based on an op­ti­cal re­fract­ing tele­scope. They are equipped with some form of graphic im­age pat­tern (a ret­i­cle) mounted in an op­ti­cally ap­pro­pri­ate po­si­tion in their op­ti­cal sys­tem to give an ac­cu­rate aim­ing point. Tele­scopic sights are used with all types of sys­tems that re­quire ac­cu­rate aim­ing but are most com­monly found on firearms, par­tic­u­larly ri­fles. Other types of sights are iron sights, re­flec­tor (re­flex) sights, and laser sights. The op­ti­cal com­po­nents may be com­bined with op­to­elec­tron­ics to form a night scope.

Re­flex Sight

An­other type of op­ti­cal sight is the re­flec­tor (or ‘re­flex’) sight, a gen­er­ally non-mag­ni­fy­ing op­ti­cal de­vice that al­lows the user to look through a glass el­e­ment and see a re­flec­tion of an il­lu­mi­nated aim­ing point or some other im­age su­per­im­posed on the field of view. These sights have been around for over 100 years and been used on all types of weapons and de­vices.

Col­li­ma­tor Sight

A col­li­ma­tor sight is a type of op­ti­cal sight that al­lows the user look­ing into it to see an il­lu­mi­nated aim­ing point aligned with the de­vice the sight is at­tached to re­gard­less of eye po­si­tion (with lit­tle par­al­lax). Col­li­ma­tor sights are ‘blind’ sights; that is, they are used with both eyes open while one looks into the sight, with one eye open and mov­ing the head to al­ter­nately see the sight and then at the tar­get, or us­ing one eye to par­tially see the sight and tar­get at the same time. Col­li­ma­tor sights are a rel­a­tively old idea, be­ing used in many forms for al­most 100 years. They are also re­ferred to as col­li­mat­ing sights or ‘oc­cluded eye gun sight’ (OEG).

Laser Sight

The laser has in most firearms ap­pli­ca­tions been used as a tool to en­hance the tar­get­ing of other weapon sys­tems. For ex­am­ple, a laser sight is a small, usu­ally vis­i­ble-light laser placed on a hand­gun or a ri­fle and aligned to emit a beam par­al­lel to the bar­rel. Since a laser beam has low di­ver­gence, the laser light ap­pears as a small spot even at long dis­tances; the user places the spot on the de­sired tar­get and the bar­rel of the gun is aligned (but not nec­es­sar­ily al­low­ing for bul­let drop, windage, dis­tance be­tween the di­rec­tion of the beam and the axis of the bar­rel, and the tar­get mo­bil­ity while the bul­let trav­els).

Most laser sights use a red laser diode. Oth­ers use an in­frared diode to pro­duce a dot in­vis­i­ble to the naked hu­man eye but de­tectable with night vi­sion de­vices. The firearms adap­tive tar­get ac­qui­si­tion mo­d­ule LLM01 laser light mo­d­ule com­bines vis­i­ble and in­frared laser diodes. In the late 1990s, green diode pumped solid state (DPSS) laser sights (532 nm) be­came avail­able. Modern laser sights are small and light enough for at­tach­ment to the firearms.

Red Dot Sight

A red dot sight is a com­mon clas­si­fi­ca­tion for a type of non-mag­ni­fy­ing re­flec­tor sight for firearms, and other de­vices that re­quire aim­ing, that gives the user an aim point in the form of an il­lu­mi­nated red dot. A stan­dard de­sign uses a red light-emit­ting diode (LED) at the fo­cus of col­li­mat­ing op­tics which gen­er­ates a dot style il­lu­mi­nated ret­i­cle that stays in align­ment with the weapon the sight is at­tached to re­gard­less of eye po­si­tion (nearly par­al­lax free). They are con­sid­ered to be fast ac­qui­si­tion and easy to use gun sights for tar­get shoot­ing, hunt­ing, and in po­lice and mil­i­tary ap­pli­ca­tions. Aside from firearm ap­pli­ca­tions, they are also used on cam­eras and tele­scopes. On cam­eras they are used to pho­to­graph fly­ing aircraft, birds in flight, and other dis­tant, quickly mov­ing ob­jects. Tele­scopes have a nar­row field of view and there­fore are of­ten equipped with a sec­ondary ‘fin­der scope’ such as a red dot sight.

Holo­graphic Weapon Sights (HWS)

Holo­graphic weapon sights use a laser trans­mis­sion holo­gram of a ret­i­cle im­age that is recorded in three-di­men­sional space onto holo­graphic film at the time of man­u­fac­ture. This im­age is part of the op­ti­cal view­ing win­dow. The recorded holo­gram is il­lu­mi­nated by the col­li­mated light of a laser diode built into the sight. The sight can be ad­justed for range and windage by sim­ply tilt­ing or piv­ot­ing the holo­graphic grat­ing. To com­pen­sate for any change in the laser wave­length due to tem­per­a­ture, the sight em­ploys a holog­ra­phy grat­ing that dis­perses the laser light by an equal amount but in the op­po­site di­rec­tion as the holo­gram form­ing the aim­ing ret­i­cle. Like the re­flec­tor sight, the holo­graphic sight is not ‘par­al­lax free’, hav­ing an aim-point that can move with eye po­si­tion. This can be com­pen­sated for by hav­ing a holo­graphic im­age that is set at a fi­nite dis­tance with par­al­lax due to eye move­ment be­ing size of the op­ti­cal win­dow at close range and di­min­ish­ing to zero at the set dis­tance (usu­ally around a de­sired tar­get range of 100 me­tres).

Since the ret­i­cle is a trans­mis­sion holo­gram, il­lu­mi­nated by a laser shin­ing

through holo­gram pre­sent­ing a re­con­structed im­age, there is no need for the sight ‘win­dow’ to be par­tially blocked by a semi-sil­vered or di­elec­tric dichroic coat­ing needed to re­flect an im­age in stan­dard re­flex sights. The op­ti­cal win­dow in a holo­graphic weapon sight looks like a piece of clear glass with an il­lu­mi­nated ret­i­cle in the mid­dle. The aim­ing ret­i­cle can be an in­fin­itely small dot whose per­ceived size is given by the acu­ity of the eye. For some­one with 20/20 vi­sion, it is about one minute of arc. One draw­back of a holo­graphic sight is shorter bat­tery life when com­pared to re­flex sights that use LEDs, such as red dot sights. How­ever, the holo­graphic weapon sight is op­ti­cally, elec­tron­i­cally, and other­wise su­pe­rior to red dot sights. The two types of sight dif­fer in op­ti­cal per­for­mance and con­struc­tion.

Diopter Sights

The diopter is an aper­ture sight com­po­nent used to as­sist the aim­ing of de­vices, mainly firearms, air­guns and cross­bows. It is found in par­tic­u­lar as a rear sight el­e­ment on ri­fles.

The diopter is in prin­ci­ple a height and side­ways (el­e­va­tion and windage) ad­justable oc­cluder with a small hole (aper­ture), and is placed close in front of the shooter’s aim­ing eye. Through this small hole the shooter can view the front sight com­po­nent(s) and the in­tended tar­get. The typ­i­cal oc­cluder used in tar­get shoot­ing diopters is a disc of about 2.5 cm (1 in) in di­am­e­ter with a small hole in the mid­dle.

The small diopter view­ing open­ing en­sures the shooter’s eye is very pre­cisely and con­sis­tently cen­tred be­hind the diopter sight. The diopter sight is easy to use and usu­ally al­lows for very ac­cu­rate aim­ing, be­cause a rel­a­tive long sight­ing line can be used.

Modern As­sault Ri­fles

Most modern as­sault ri­fles in use have op­ti­cal sights such as the red dot sights and diopter sights. Most of them can be fit­ted with a de­tach­able scope mounts and night vi­sion de­vices. Some ex­am­ples are given be­low.

The Ta­vor TAR-21 as­sault ri­fle was de­vel­oped by Is­rael Mil­i­tary In­dus­tries (IMI) back in the early 1990s. This weapon is sim­ple, tough and ver­sa­tile. It was adopted by Is­rael in 2006 and be­came a stan­dard is­sue in­fantry ri­fle. This as­sault ri­fle has been ex­ported to more than 20 coun­tries. This weapon has a stan­dard Pi­catinny-type rail and is com­pat­i­ble with var­i­ous scopes or night vi­sion sys­tems. It comes with red-dot sight as stan­dard.

The Steyr AUG (uni­ver­sal army ri­fle) was de­signed in Aus­tria. It has been adopted by Aus­trian Army back in 1977. When it first ap­peared it was con­sid­ered to be rev­o­lu­tion­ary in many re­spects. Im­me­di­ately after its in­tro­duc­tion the AUG be­came pop­u­lar. The orig­i­nal model has in­te­gral 1.5x mag­ni­fi­ca­tion sight. It is de­signed for up to 300 m range. Also there are back-up iron sights for emer­gency use. Newer mod­els lack in­te­gral sights, but have Pi­catinny-type rail and can be fit­ted with any sights.

The G36 as­sault ri­fle has been de­signed by Heck­ler & Koch to re­place the G3 as­sault ri­fle in ser­vice with the Bun­deswehr. Since 1995 the G36 is a stan­dard is­sue in­fantry ri­fle with the Ger­man armed forces. This weapon be­came an ex­port suc­cess. It has been ex­ported to more than 40 coun­tries around the world. Sights are built into the car­ry­ing han­dle. A stan­dard Ger­man Army ri­fle has a dual sight sys­tem. It con­sists of one 3.5x mag­ni­fi­ca­tion scope, for long-range ac­cu­rate

shoot­ing and one 1x mag­ni­fi­ca­tion red dot sight above it, for close ranges.

The AK-74M with the Rus­sian Army can be fit­ted with col­li­ma­tor and op­ti­cal sights to en­sure fast and pre­cise tar­get­ing with im­proved com­bat ef­fi­ciency. The stan­dard op­ti­cal sight is the 1P29 uni­ver­sal sight with 4x mag­ni­fi­ca­tion. It has a field of vi­sion of 80.

SIG SG 550 is the as­sault ri­fle with the Swiss Army. Sight­ing equip­ment con­sists of a flip-up front sight and ad­justable rear diopter. It has a sight­ing range of 400 m. Ev­ery ri­fle can be fit­ted with a de­tach­able scope mount. Swiss Army ri­fles are of­ten used with 4x mag­ni­fi­ca­tion scope. Cur­rent pro­duc­tion mod­els are avail­able with a Pi­catinny-type rail and can mount var­i­ous scopes, red dot or night vi­sion sights.

In­dia’s Ex­cal­ibur ri­fle fires a stan­dard NATO 5.56x45 mm am­mu­ni­tion. It fea­tures high rugged­ness for bat­tle­field engagements and is lighter to han­dle. It is well suited for low in­ten­sity con­flicts and close quar­ter com­bat sit­u­a­tions. The ri­fle is also er­gonom­i­cally de­signed with fold­ing butt and Pi­catinny rails for mount­ing op­ti­cal/elec­tronic de­vices.

Com­pa­nies Deal­ing with Sight­ing Sys­tems

Aim­point AB is a sup­plier of elec­tro-op­ti­cal sight­ing sys­tems in­clud­ing pas­sive red dot col­li­ma­tor sight, laser de­vice, fire con­trol sys­tems and mounts. The com­pany strength­ened its po­si­tion as mar­ket leader when it was awarded the first multi-year con­tract ever for red dot sights by the US Army in 1997. Since then, Aim­point has con­tin­ued to de­liver large quan­ti­ties of sights to the US Army, French Army, US Air Force, US SOCOM, Swedish Army, Nor­we­gian Army, Dutch Army, Dan­ish Army and Ital­ian Army.

Op­tex Sys­tems. US-based op­ti­cal sight­ing sys­tems man­u­fac­turer Op­tex Sys­tems has se­cured a con­tract to sup­ply new periscopes for the US Army. Un­der the terms of the $8,41,000 deal, the com­pany will sup­ply an undis­closed num­ber of periscopes to be in­stalled aboard the army’s Abrams tanks. The periscopes will fea­ture glass and plas­tic laser pro­tec­tion for sol­diers’ eyes.

Pho­tonic. is a glob­ally ac­tive con­trac­tor for op­ti­cal and opto-elec­tronic in­stru­ments since 1986, whose op­ti­cal prod­ucts en­joy an ex­cel­lent rep­u­ta­tion in the field of in­fantry and ar­tillery weapon sys­tems. The well-known man­u­fac­turer of re­li­able and highly ef­fi­cient op­ti­cal in­stru­ments has de­vel­oped a unique sight­ing sys­tem to lay muz­zle-loaded in­di­rect fire weapons such as 60mm mor­tars.

Thales Op­tics. The Sight Unit Small Arms, Trilux (or SUSAT) is a 4x with tele­scopic sight with tri­tium-pow­ered il­lu­mi­na­tion, utilised at dusk or dawn. The full name of the cur­rent model is the SUSAT L9A1. The SUSAT sight was de­vel­oped in the United King­dom by Royal Ar­ma­ments Re­search De­vel­op­ment Es­tab­lish­ment (RARDE) and is man­u­fac­tured by United Sci­en­tific In­stru­ments and Avimo, now known as Thales Op­tics.

Tri­ji­con has led the in­dus­try in the de­vel­op­ment of su­pe­rior any-light aim­ing sys­tems since the com­pany’s found­ing in 1981. World-renowned for its in­no­va­tive ap­pli­ca­tions of tri­tium and ad­vanced fi­bre op­tics, Tri­ji­con man­u­fac­tures the most ad­vanced ri­fle­scopes and sights for tac­ti­cal and sport­ing ap­pli­ca­tions.

A US Army sol­dier checks through his ri­fle scope for any sus­pi­cious ac­tiv­ity at an ob­ser­va­tion point in Iraq

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