A Shorthand for Writing Projectile Diameters —When Keeping Records of How Each Diameter Performed
Testing pellets (.22): JSB Domes 15.89gr (and their rebranded twins) come in 4 diameters (head sizes) — so, how do I keep it short when noting down which diameter produced which group?
H&N Baracuda Match and H&N Field Target Trophy — come each in 3 diameters. RWS SuperField comes in 2 diameters.
Testing Slugs — there is only 1 diameter from some manufacturers (FX, AVS), there are 2 diameters from most others (H&N, JSB, Griffin), and NielsenSpecialtyAmmo.com alone offers us 5 diameters.
Again, how can I keep my notes short, and the entries in my ballistic calculator short as well?
➔ So, for myself I came up with an abbreviation system for projectile diameters to keep it short:
[Cell phone users — please turn your screen to landscape, otherwise the width of the table will jumble up the data — and it still might do that]
HEAD SIZES / DIAMETERS 
[Cell phone users — please turn your screen to landscape.]
Abbreviations used in the Head Size Table below:
ctv = cvt mm = converted inches into mm
in = size in inches
mm = size in mm
ctv = cvt in = converted mm into inches
abbr = suggested abbreviations, based on last digit of the metric size with H=head size
abbr2 = alt abbr = alternative abbreviations, based on the last digit of the metric size
imp abbr = imperial abbreviations
Diameters/ Head Sizes and Convenient Abbreviations: 
cvt: 5.474 5.486 5.50 5.512 5.525 5.537 5.54 —— 5.563
in: .2155 .216 .2165 .217 .2175 .218 .2185 —— .219
mm: 5.48 5.49 5.50 5.51 5.52 5.53 5.54 5.55 5.56
cvt: .2157 .2161 .2165 .2169 .2173 .2177 .2181 .2185 .2189
abbr: H8 H9 H0 H1 H2 H3 H4 H5 H6
abbr2: ('8 ) ('9) ('0) ('1) ('2) ('3) ('4) ('5) ('6)
imp abbr: I did not find a good way to abbreviate the imperial size
Hope this is helpful to some,
Matthias
Testing pellets (.22): JSB Domes 15.89gr (and their rebranded twins) come in 4 diameters (head sizes) — so, how do I keep it short when noting down which diameter produced which group?
H&N Baracuda Match and H&N Field Target Trophy — come each in 3 diameters. RWS SuperField comes in 2 diameters.
Testing Slugs — there is only 1 diameter from some manufacturers (FX, AVS), there are 2 diameters from most others (H&N, JSB, Griffin), and NielsenSpecialtyAmmo.com alone offers us 5 diameters.
Again, how can I keep my notes short, and the entries in my ballistic calculator short as well?
➔ So, for myself I came up with an abbreviation system for projectile diameters to keep it short:






ctv = cvt mm = converted inches into mm
in = size in inches
mm = size in mm
ctv = cvt in = converted mm into inches
abbr = suggested abbreviations, based on last digit of the metric size with H=head size
abbr2 = alt abbr = alternative abbreviations, based on the last digit of the metric size
imp abbr = imperial abbreviations


cvt: 5.474 5.486 5.50 5.512 5.525 5.537 5.54 —— 5.563
in: .2155 .216 .2165 .217 .2175 .218 .2185 —— .219
mm: 5.48 5.49 5.50 5.51 5.52 5.53 5.54 5.55 5.56
cvt: .2157 .2161 .2165 .2169 .2173 .2177 .2181 .2185 .2189
abbr: H8 H9 H0 H1 H2 H3 H4 H5 H6


abbr2: ('8 ) ('9) ('0) ('1) ('2) ('3) ('4) ('5) ('6)

imp abbr: I did not find a good way to abbreviate the imperial size
Hope this is helpful to some,

Matthias