Hello
9412765;
Welcome to AH.com
It just happens that I addressed this question recently in
https://www.africahunting.com/threads/what-is-your-minimum-buffalo-cartridge.59423/page-3
To change the front sight, the formula is:
- Correction required on target (for example: 4") multiplied by sight radius i.e. distance between front & rear sights (on a factory CZ 550 barrel: 19") divided by distance to the target in inches (100 yards: 3,600"). In this example: 4" x 19" / 3,600" = 0.02" sight height correction.
- To convert 0.02" to millimeters, multiply by 25.4. In this example: 0.02" x 25.4 = 0.5 mm.
- If a group is 4" low at 100 yards, this means you need a front sight that is 0.02" (0.5 mm) shorter.
- Measure your front sight top of sight to bottom of base with a caliper. Subtract 0.02" or 0.5 mm to this measurement, and try to order a new front sight from CZ at shop.cz-usa.com, they used to have a full line going from size 1 to 15 in 0.25 mm (~.01") increment. In your case, for example, if there is currently a #5 on your rifle, you need a #3.
CZ 550 front sight sizes:
CZ 550 front sights #4 to #14 in supposedly 0.25 mm (~.01") height increment. The coarse white paint can be easily removed and redone more delicately if needed...
However, my own caliper measurements on the sights I have show inconsistencies in the markings and inconsistencies in the 0.25 mm theoretical progression:
View attachment 374994
- stamped #1: apparent spec 4.8 mm(?). Mine measure 4.83 mm, 4.85 mm (+ unmarked 4.81 mm)
- unmarked assumed to be #2 spec 5 mm: Mine measure 4.98 mm, 5.04 mm
- unmarked assumed to be #3 spec 5.1 mm(?): Mine measure 5.1 mm, 5.11 mm
- engraved #4: spec 5.25 mm. Mine measure 5.28 mm, 5.3 mm
- engraved #5: spec 5.5 mm. Mine measure 5.56 mm, 5.57 mm, 5.57 mm, 5.58 mm
- engraved #6: spec 5.75 mm. Mine measures 5.79 mm
- engraved #7: spec 6 mm. Mine measure 6.02 mm, 6.02 mm, 6.02 mm
- engraved #8: assumed spec 6.25 mm(?). Mine measure 6.10 mm, 6.12 mm
- engraved #9: spec 6.5 mm. Mine measure 6.53 mm, 6.53 mm, 6.56 mm
- engraved #10: spec 6.75 mm. Mine measure 6.73 mm, 6.73 mm
- engraved #11: apparent spec 6.9 mm. Mine measure 6.88 mm, 6.93 mm
- engraved #12: apparent spec 7 mm. Mine measure 7.03 mm, 7.03 mm, 7.05 mm
- engraved #13: apparent spec 7.25 mm. Mine measure 7.26 mm, 7.26 mm
- engraved #14: assumed spec 7.35(?). Mine measures 7.33 mm
Most CZ 550 front sights are engraved for size underneath
Your 0.222" front sight is 5.6 mm (0.222 x 25.4 = 5.6 mm). This puts it closest to the spec for #5.
If it proves difficult to order from CZ directly, you can also procure the sights from Numrich:
Or you can use the opportunity to put a fiber optic or a wide white bead front sight from New England Custom Shop. The only limitation is that they offer far fewer sizes with only increment of 1 mm (~0.04").
But, since the sight picture with bright green or red fiber optics is different, and a wide bead also gives a different sight picture, it is worth trying if you want one of these.
I hope this helps. PM me if you cannot find for sale what you need...
