9mm Velocity by Barrel Length

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Velocity and barrel length data for 9x19mm Parabellum, also known as 9mm Luger and so on. The following data is sourced from Ballistics by the Inch.

Barrel Length Cor-Bon 90 gr JHP +P Cor-Bon 115 gr JHP +P Cor-Bon 125 gr JHP +P Cor-Bon 115 gr DPX Federal 115 gr JHP Federal 135 gr Hydra-Shok JHP (low recoil) Federal 105 gr Expand'g FMJ Federal 124 gr Hydra-Shok JHP Federal 147 gr Hydra-Shok JHP Speer 124 gr Gold Dot Short Barrel
18" 1754 1543 1449 1458 1297 1194 1370 1231 1038 1395
17" 1766 1550 1421 1455 1320 1207 1381 1250 1096 1400
16" 1740 1525 1430 1476 1295 1185 1358 1243 1073 1379
15" 1768 1536 1392 1416 1304 1194 1364 1244 1090 1375
14" 1767 1532 1405 1440 1295 1182 1372 1241 1090 1390
13" 1738 1517 1477 1427 1281 1183 1343 1237 1081 1378
12" 1716 1514 1385 1380 1282 1184 1273 1225 1081 1361
11" 1690 1496 1372 1391 1268 1166 1318 1212 1059 1360
10" 1647 1474 1372 1379 1253 1167 1314 1211 1067 1338
9" 1663 1476 1369 1377 1238 1161 1307 1212 1055 1345
8" 1634 1458 1366 1366 1234 1145 1278 1180 1047 1329
7" 1619 1446 1329 1350 1223 1136 1258 1161 1040 1316
6" 1566 1402 1312 1332 1188 1113 1235 1131 1030 1284
5" 1539 1372 1282 1315 1166 1085 1194 1115 1007 1259
4" 1444 1316 1226 1265 1094 1039 1140 1061 951 1203
3" 1345 1245 1170 1215 1029 976 1074 988 902 1108
2" 1215 1134 1061 1132 948 909 985 900 837 1074

Best Barrel Length For 9mm

Based on the data above, it appears that almost all loads tested got their greatest percentage increase in velocity up until about a 7" barrel length. Velocity did of course increase further with longer barrels, but to a much smaller degree. For example, going from a 4" barrel to 7" (a 3 inch difference), every load got well over a 100 fps increase in velocity. However, going a full 10 inches longer up to a 17" barrel gained most of the tested loads under 100 feet per second in velocity. In fact, going from a 17 inch barrel up to 18 inches, actually LOST velocity in all but two of the loads, although the decrease was negligible in those instances.

It appears that overall, the optimal barrel length for 9mm (for something like an AR-15 pistol build, SBR, or similar setup), is about 7 to 8 inches for maximum efficiency and handling, though going longer can still have benefits. If you still wanted to maintain an ultra-short setup with a suppressor, you could go even shorter with barrel length, as the additional length of the suppressor will increase velocity. Even at 7-8" barrel, the additional length of a suppressor would still allow the pistol or SBR to remain more compact than a 16" barrel. A 7" barrel with a 7" suppressor would still give an overall length of 14 inches, so going up to 10" for a little extra velocity would put you at just about 17" with a suppressor, which is still going to handle better than a 16" barrel, along with the benefits of being suppressed. If you were looking for a typical rifle setup, there appears to be no major reason to go above the federal 16" barrel requirement, unless local laws differ, or whatever the case may be.

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