Gun Caliber Conversions Chart



Common name

Bore diameter (inches)

Bullet/Groove diameter (inches)

Bullet/Groove

diameter (MM)

.50 cal

.500"

.510

12.954

.475 cal

-

.475

12.065

.45 cal rifle

.450

.458

11.633

.45 revolver

-

.454

11.531

.45 revolver

-

.452

11.480

.45 ACP

-

.451

11.455

.44 Mag.

-

.429

10.896

.416 cal

-

.416

10.566

.41 cal

-

.410

10.414

.40cal/10mm

-

.400

10.160

.375 cal

-

.375

9.525

9.3mm

-

.366

9.300

.35 cal rifle

.350

.358

9.093

.357 Mag

.38 Spec

.350

.357

9.067

9mm, .380

.357 SIG

-

.355

9.017

.348 cal

.340

.348

8.839

.338 cal

.330

.338

8.585

.33 cal

-

.333

8.382

8mm

.315

.323

8.204

.32 Special

.313

.321

8.153

.32-20 cal

-

.312

7.924

.303 cal

7.65mm

.303

.312

7.924

7.62x39

.300-.303

.311

7.899

.30/.300 cal

.300

.308

7.832

7.5mm

-

.295

7.500

.28 cal/7mm

.275-.276

.284

7.213

.270 cal

.270

.277

7.035

.26cal/6.5mm

.256

.264

6.705

.25 cal

.250

.257

6.527

.243/6mm

.236

.243

6.172

.22 cal

.218/.219

.224

5.689

.20 cal

-

.204

5.080

.17 cal

-

.172

4.368

BB

-

.177-.180

4.495
cartridges
Shotgun Gauge and Bore Chart

Gauge 

Bore diameter
(millimeters)

Bore diameter
(inches)

6

23.3

0.92

10

19.7

0.77

12

18.5

0.73

14

17.6

0.69

16

16.8

0.66

20

15.9

0.63
24
14.7
0.58
28
14.0
0.55
32
13.4
0.526

Shotgun Shot Size Table*


LEAD SHOT


 
  Shot number  |  diameter (inches)  |  diameter (mm) |  approx no. of 
               |                     |                |  pellets in 1 oz.
_______________|_____________________|________________|_________________
               |                     |                |
 000 BUCK      |         .36         |      9.14      |        6.2
               |                     |                |
  00 BUCK      |         .33         |      8.38      |          8
               |                     |                |
   0 BUCK      |         .32         |      8.13      |          9
               |                     |                |
   1 BUCK      |         .30         |      7.62      |         11
               |                     |                |
   2 BUCK      |         .27         |      6.86      |         15
               |                     |                |
   3 BUCK      |         .25         |      6.35      |         19
               |                     |                |
   4 BUCK      |         .24         |      6.10      |         21 
               |                     |                |
     BB        |         .18         |      4.57      |         50
               |                     |                |
      2        |         .148        |      3.76      |         90
               |                     |                |
      4        |         .129        |      3.28      |        135
               |                     |                |
      5        |         .120        |      3.05      |        170
               |                     |                |
      6        |         .109        |      2.77      |        225
               |                     |                |
      7.5      |         .094        |      2.39      |        350
               |                     |                |
      8        |         .089        |      2.26      |        410
               |                     |                |
      8.5      |         .085        |      2.16      |        470
               |                     |                |
      9        |         .079        |      2.01      |        585
               |                     |                |
     12        |         .05         |      1.3       |       2300
_______________|_____________________|________________|_________________
 

        
Shotgun STEEL SHOT

 
  Shot number  |  diameter (inches)  |  diameter (mm) |  no. of pellets
               |                     |                |      in 1 oz.
_______________|_____________________|________________|_________________
               |                     |                |
      F        |         .22         |      5.59      |         40
               |                     |                |
      T        |         .20         |      5.08      |         53
               |                     |                |
     BBB       |         .19         |      4.83      |         61
               |                     |                |
      BB       |         .18         |      4.57      |         72
               |                     |                |
      1        |         .16         |      2.79      |        103
               |                     |                |
      2        |         .15         |      3.05      |        125
               |                     |                |
      3        |         .14         |      3.30      |        154
               |                     |                |
      4        |         .13         |      3.56      |        191
               |                     |                |
      5        |         .12         |      3.81      |        244
               |                     |                |
      6        |         .11         |      2.79      |        317
               |                     |                |
      7        |         .10         |      2.54      |        422
_______________|_____________________|________________|_________________

12 Gauge size shells

shells
Home Page