Our caliber and twist rate chart (see below) indicates the twist rate
recommended for use with normally manufactured ammunition. Today's handloader,
however, has access to a wide range of heavier and longer bullets; a faster
rate of twist may be required to stabilize these bullets. For example, a 12"
twistbarrel will stabilize a heavier or longer bullet than will a 14" twistbarrel.
Basically, the twist rate you choose should be sufficient to stabilize the longest
and heaviest bullets you plan to use.
PAC-NOR has the capability to make barrels with special requirements such as
twist, rifling configuration, and bore and groove dimensions. We have made
barrels for various ballistic labs, and arms and ammunition manufacturers.
Since most of the tooling must be specially made, this type of work is done
only on a written quote basis. Please supply us with drawings for your
requirements by mail or fax so that we may accurately process your quote.
| .14 (.144") |
|
| 17 (.172") |
|
| 19 (.198") |
|
| 20 (.204") |
| 3 groove |
7" |
8.50" |
9" |
10" |
11" |
12" |
13" |
16" |
|
| 22 Rimfire (.222") |
| 6 groove |
6" |
8" |
10" |
14" |
16" |
18" |
20" |
|
| 5.45 Russian (.222") |
|
| 22 (.224") |
| 3 groove |
6" |
6.50" |
7" |
8" |
9" |
10" |
12" |
13" |
13.25" |
13.50" |
14" |
16" |
| 4 groove |
7.50" |
8" |
8.60" |
13" |
16" |
| 5 groove |
7" |
8" |
9" |
10" |
12" |
14" |
15" |
| Polygonal |
6.50" |
7" |
8" |
9" |
12" |
14" |
|
| 228 (.228") |
|
| .23 (.234") |
|
| 6mm (.243") |
| 3 groove |
7" |
8" |
9" |
10" |
11" |
12" |
13.25" |
14" |
| 4 groove |
7.50" |
8" |
8.60" |
13.75" |
14" |
| 5 groove |
5" |
6" |
7" |
9" |
12" |
13" |
15" |
16" |
|
| 25 (.257") |
|
| 6.5mm (.264") |
|
| 270 (.277") |
|
| 7mm (.284") |
| 3 groove |
8" |
9" |
10" |
11" |
12" |
13" |
14" |
15" |
| 5 groove |
7" |
9" |
9.50" |
9.52" |
10" |
| 6 groove |
8" |
9.52" |
11" |
12" |
14" |
|
| .29 cal (.298") |
|
| 30 Tight Bore (.298") |
|
| 30 (.308") |
| 3 groove |
6.50" |
7" |
7.50" |
9" |
10" |
12" |
13" |
14" |
15" |
| 5 groove |
4" |
7" |
8" |
9" |
10" |
11" |
12" |
13" |
15" |
17" |
18" |
|
| 303 British (.311") |
|
| 32-40 (.321") |
|
| 8mm (.323") |
|
| 338 (.338") |
| 5 groove |
6.50" |
7" |
9" |
9.50" |
10" |
12" |
|
| 348 (.348") |
|
| 9mm (.355") |
|
| 357 Pistol (.357") |
|
| 35 (.358") |
|
| 9.3mm (.366") |
|
| 375 (.375") |
|
| 10mm (.400") |
|
| 408 (.408") |
|
| .411 (.410") |
|
| 405 (.412") |
|
| 416 (.416") |
|
| 404 (.423") |
|
| 44 Pistol (.429") |
|
| 425 WR (.435") |
|
| 45 Pistol (.451") |
|
| 458 Rifle (.458") |
| 8 groove |
10" |
14" |
15" |
18" |
20" |
22" |
26" |
|
| 475 (.475") |
|
| 50 cal (.500") |
|
| 505 cal (.505") |
|
| 50 (.510") |
|
| 50 BMG (.510") |
| 8 groove |
10" |
13" |
14" |
15" |
20" |
|
| 550 (.550") |
|
| 577 (.585") |
|
| 600 Nitro (.620") |
|
| .685 (.685") |
|
| 700 Nitro (.700") |
|
| 705 (.705") |
|
| 12 ga. (.729") |
|
| 20mm (.825") |
|
|
