STANDARD OPEN SIGHT ADJUSTMENT

With the exception of the "American Classic" and maybe a couple of other variants, the CZ-452 types are almost all equipped with what are probably the finest mid-barrel style open sights on any rifle available today.    The construction is somewhat akin to those found on the better variants of the German Mauser K98 military rifles of the WW1 / WW2 era.    The calibration on the rear slide bar is in metres, ranging from 25 to 200 - (300 metres in the case of the relatively rare 'UltraLux' version).    All discrete range settings are locked by a rack and toothed plunger arrangement with some intermediate settings available . . . the calibration graduations appear to be set for typical high velocity ammunition, rather than standard target style or hyper-velocity ammo.    Windage adjustments can be made through a sliding rear sight blade positioned by means of opposing screws in the main sight leaf.    Elevation adjustments, to calibrate the sight for a specific ammo can be made by fore and aft movement of the blade front sight in a tapered ramp.    Both adjustment features have index marks as a guide . . . however, for those who have no owners manual, the following information will allow you to set these sights to your liking.

For most owners using any of the open-sighted CZ-452's as an all-purpose plinking / target / small-game hunting rifle, I would suggest setting the rear blade unit to the '50 Metres' mark on the slide, and then adjusting the front sight for correct calibration at around 50 yards range.    When doing this, make up your mind ahead of time what style of ammunition you will be using most of the time . . . standard, high-velocity or hyper-velocity !     This will then ensure that the range calibration marks on the slide do bear some reasonable semblance of reality in day-to-day shooting activities.

With such typical open sights, this brings up an interesting point !    What sort of sight picture should you use for such shooting ?    The traditional "top of foresight blade level with the top of the rear blade, and centred laterally in the notch" is by far the best approach.    How about the aiming point ?      In formal target shooting with these regular open sights, the traditional "six-o'clock hold" on the base of the 'black bull' with just a hair-line trace of white showing, is by far the best method of choice.

However, for informal plinking and small game/vermin hunting, a different approach is recommended.     I would suggest using a dead-centre hold on the critical area of the target for best "kill" probability . . . beats having to mentally estimate the point of aim at some specific distance below the desired point of impact.     In order to make this work, one should move the front sight blade rearward along its' ramp, thus raising the top of the blade relative to the bore of the barrel.     By doing this you are lowering the point of impact so that it coincides with the point of aim at the chosen sight-in distance.

Elevation:    Loosening the locking screw and sliding the front blade rearwards will lower the point of impact . . . sliding it forwards will raise it. Each marked division on the front sight ramp will move the point of impact by approximately 0.6 inches at a range of 50 metres.    I say approximately because there are marked variations in barrel length, and hence sight radius, between models.

Azimuth:     To adjust for lateral sighting errors - windage - the rear sight blade must be moved laterally in the direction opposite to the point of impact error.  That is . . . if the shot falls to the left of the point of aim, then move the rear blade to the right.    This would be accomplished by loosening the screw on the right of the blade and tightening the opposing left side screw.    One full turn of the screws will typically move the point of bullet impact approximately 2.0 inches at a range of 50 metres.

STANDARD SIGHT MODIFICATIONS / IMPROVEMENTS

1.   Improving the Standard Rear Blade

Now I said above that these are the finest open sights currently available . . . that doesn't mean that they can't be improved !    For antiques like myself, with cataracts in both eyes, and maybe wearing abominable tri-focal glasses, it becomes very obvious that the ultra-fine Vee-notch in the rear sight blade is a definite handicap.   So my recommendation here is a little judicious use of either a round tapered or a thin flat Swiss file to open it up, followed by re-touching the bluing with one of the commercial gel or liquid cold blues . . . be careful not to open the notch up off-centre.    I have found, for my own usage, that a half-round or square notch of some 3/32 inch width has made all the difference in the world . . . I can now see the front sight "blur" against the target "blur".     It enabled me to unofficially shoot the highest score in one of the CMP Centennial Rimfire Sporter matches with my UltraLux . . . ( I say unofficial, because having already won the 'scope sighted event that day with my American Classic, my open-sighted attempt was disallowed - lol ).

2.   Installing a Rear 'Ghost Ring' Blade

Now what else can be done ?    Well, assuming you're not shooting official CMP matches, where use of any rear aperture puts one in the 'scope class, I would strongly suggest the replacement of the rear sight blade with one of Brookies' "ghost ring" sight blades.    The 3/32 inch diameter version has proven ideal for myself.

But what about the "best" sight picture when using the ghost ring and front blade configuuration ?     For informal plinking and small game shooting I would suggest a "top of front blade" in centre of rear aperture hold on the desired impact point on the target.     Contrariwise to this, if using this sight configuration for formal target shooting, a rather odd arranngement of centring the bull in the rear aperture, while holding the top of the front blade at the six o'clock position on the bull offers the greatest possibility of accuracy.

Even this set up can be improved upon still further.     Go to your local archery shop . . . preferably one that deals in a lot of accessories . . . and buy some replacement fibre-optic filaments.     These typically come in various diameters and 5 ~ 6 inch lengths and assorted fluorescent colours . . . I find the greens give the best overall effect.   The optimum diameter for the filament will depend upon the sort of shooting being planned.   For formal bulls-eye target events something around .015 ~ .025 inches seems to work best.    The larger diameters are better for hunting usage.    Now cut a short length from one of these filaments, say a couple of inches, and heating very carefully about 1/2 ~ 3/4 inch from one end, (boiling water or holding near a flame), make a U-shaped bend of about 1/16" ~3/32" radius in the filament.    Sort of like a trombone slide !     

This is where it gets tricky !     Using a round or 3-square Swiss file, make a shallow groove fore and aft in the top of the front sight blade.     Now, using a gel-type CyanoAcrylate cement - (Crazy Glue !) - bond the short leg of the bent filament to the top of the sight blade with the U-loop in the front and the long leg pointing downwards and backwards alongside the base of the sight ramp.    At this point I find I usually need help from an amused bystander, my wife, to get me unglued from the whole mess !    Once the sight hood is slid back on, it holds and protects the long lower leg of the filament from accidental damage.   Now test fire the beast using a true centre hold of both ghost ring and filament "dot" on the target.    If, as I've found, the shots are now too low, and not enough adjustment is available, you may have to remove the filament, file the front sight blade lower, re-groove it, make a new filament loop and repeat the process.    An alternative method - and much simpler - is to merely glue a short, say 1/2", length of the filament to the top of the grooved front sight blade.    The light pick-up is diminished but adequate in open shooting areas.

Notwithstanding the improvement in visibility obtainable by using the optical filaments, be aware that this idea only works when the overhead available light is adequate.    Those of us who have tried it have discovered this to be a major problem . . . when used for formal target shooting from under a covered firing point, inadequate lighting does not allow the filament ends to glow in the expected manner.

3.   Buckhorn Sights, Anyone ?

Want to take the ghost ring and fibre optic filament idea a stage further ?    What if we wanted to adapt the ghost ring configuration to say, formal CMP competition ?  The basic solution I have been trying, has been to convert one of Brookies' ghost ring blades into a traditional old-fashioned "buckhorn" configuration.    To do this, file out a small narrow Vee-shaped notch in the top of the ghost ring.   Voila !    It has now become an "open sight", but with some vestige of an aperture still remaining.    I have not yet shot such an arrangement in competition but feel that it would probably be "legal".    And they said the kid could never be that smart . . . . or sneaky !