Description
Somchem's S321 is a rifle propellant powder with a medium burn rate, designated at a 2.7 on the burn rate scale, making it an excellent choice for a wide range of rifle calibers. Its physical form is a spherical (ball) powder, which facilitates superior metering properties, ensuring consistent charge weights that are highly valued in progressive reloading presses. S321 exhibits commendable temperature stability, maintaining reliable performance across varying environmental conditions, a crucial factor for precision shooters and hunters alike. This propellant is ideally suited for medium rifle cartridges, with popular pairings including calibers such as .223 Remington and .308 Winchester, where it is known to produce consistent velocities and tight standard deviations. When approaching load development, handloaders should note its robust ignition characteristics and efficient burnout, which contribute to its reputation for producing clean-burning loads. For experienced reloaders, S321 offers distinct advantages in achieving precise, repeatable performance due to its consistent metering and adaptability in diverse atmospheric conditions.
Specifications
Burn Rate
5.6 (Medium)
Bulk Density
0.990 g/cm³
Density
1.620 g/cm³
Temperature Sensitivity
Low
Suitable Substitutes
Powders with a similar burn rate that may be suitable alternatives (also see burn rate chart):
Standard Loads — Somchem S321
Verified load data combinations using Somchem S321.
.17 Rem.
Berger .172 | 25gr | Berger Varmint 25gr
.17 Rem.
Hornady .172 | 25gr | Hornady V-MAX 25gr
.20 BR
Berger .204 | 35gr | Berger FB Varmint 35gr
.20 BR
Berger .204 | 40gr | Berger Varmint 40gr
.20 BR
Berger .204 | 55gr | Berger Varmint 55gr
.20 BR
Hornady .204 | 32gr | Hornady V-MAX 32gr
.20 BR
Hornady .204 | 40gr | Hornady V-MAX 40gr
.20 BR
Hornady .204 | 45gr | Hornady SP 45gr
.20 BR
Impala Bullets .204 | 30gr | Impala LWHV LS 30gr
.20 BR
Nosler .204 | 32gr | Nosler Varmageddon HP 32gr
.20 BR
Nosler .204 | 32gr | Nosler CT Ballistic Silvertip RN 32gr
.20 BR
Nosler .204 | 32gr | Nosler Varmageddon 32gr
.20 BR
Nosler .204 | 32gr | Nosler Ballistic Tip Varmint 32gr
.20 BR
Nosler .204 | 32gr | Nosler Ballistic Tip Lead Free 32gr
.20 BR
Nosler .204 | 40gr | Nosler Ballistic Tip Varmint 40gr
.20 BR
Peregrine .204 | 34gr | Peregrine VLR-4 34gr
.20 BR
Peregrine .204 | 36gr | Peregrine VLR-5 36gr
.20 BR
Sierra .204 | 32gr | Sierra BlitzKing 32gr
Subsonic Loads — Somchem S321
Verified subsonic load data combinations using Somchem S321.
.30-06 Spring.
Berger .308 | 230gr | Berger Hybrid Target 230gr
.30-06 Spring.
Berger .308 | 230gr | Berger Hybrid OTM Tactical 230gr
.30-06 Spring.
Discreet Ballistics .308 | 188gr | Discreet Ballistics Selous Machined Expander 188gr
.30-06 Spring.
Hornady .308 | 175gr | Hornady Sub-X 175gr
.30-06 Spring.
Hornady .308 | 190gr | Hornady Sub-X 190gr
.30-06 Spring.
Lapua .308 | 200gr | Lapua Subsonic 200gr
.30-06 Spring.
MAKER .308 | 200gr | MAKER 200 Grain .308 Expanding Subsonic Blackout Bullets 200gr
.30-06 Spring.
MAKER .308 | 220gr | MAKER 300 blackout 220gr
.30-06 Spring.
Peregrine .308 | 155gr | Peregrine Subsonic 155gr
.30-06 Spring.
Reichenberg .308 | 154gr | Reichenberg HDB Subsonic 154gr
.30-06 Spring.
Reichenberg .308 | 200gr | Reichenberg Subsonic 200gr
.30-06 Spring.
Sierra .308 | 220gr | Sierra MatchKing 220gr
.30-06 Spring.
Styria Arms | AERO .308 | 95gr | AERO SUB-I,- smax:11.30 95gr
.30-06 Spring.
Styria Arms | AERO .308 | 115gr | AERO SUB,- smax:11.40 115gr
.30-06 Spring.
Styria Arms | AERO .308 | 190gr | AERO SUB,- smax:23.90 190gr
.308 Win.
Discreet Ballistics .308 | 188gr | Discreet Ballistics Selous Machined Expander 188gr
.308 Win.
Hornady .308 | 175gr | Hornady Sub-X 175gr
.308 Win.
Hornady .308 | 190gr | Hornady Sub-X 190gr
Community Loads — Somchem S321
Sample load data calculated with Somchem S321.
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| Cartridge | Bullet | Barrel (in) | Charge (gr) | OAL (in) | Case Volume (GoW) | Max. Pressure (psi) | Muzzle Velocity (fps) |
|---|---|---|---|---|---|---|---|
| .224 | 55gr | Hornady Traditional/FMJ | 24.0 | ••.• | 2.26 | 30.0 | 51,006 (93%) | 3192 | |
| .224 | 53gr | Hornady V-MAX | 23.7 | 25.4 | 2.26 | 29.6 | 51,790 (94%) | 3176 | |
| .224 | 53gr | Hornady V-MAX | 23.7 | 26.1 | 2.26 | 29.6 | 47,733 (87%) | 3146 | |
| .224 | 55gr | Sierra SP Blitz | 23.7 | ••.• | 2.26 | 29.6 | 46,425 (84%) | 3091 | |
| .224 | 55gr | Prvi Partizan FMJ BT | 24.0 | ••.• | 2.26 | 30.0 | 45,513 (83%) | 3087 | |
| .224 | 55gr | Hornady Traditional/FMJ | 24.0 | ••.• | 2.26 | 30.0 | 44,934 (82%) | 3077 | |
| .224 | 50gr | Impala RNFP KO | 24.0 | ••.• | 2.26 | 30.0 | 40,785 (74%) | 3071 | |
| .224 | 53gr | Hornady V-MAX | 23.7 | 25.4 | 2.26 | 29.6 | 43,500 (79%) | 3064 | |
| .224 | 55gr | Sierra SP Blitz | 23.7 | ••.• | 2.26 | 29.6 | 42,947 (78%) | 3022 | |
| .224 | 55gr | Hornady SP | 24.0 | ••.• | 2.23 | 30.0 | 36,898 (67%) | 2897 | |
| .224 | 55gr | Hornady Traditional/FMJ | 24.0 | ••.• | 2.26 | 30.0 | 34,960 (64%) | 2854 | |
| .224 | 65gr | Sierra GameKing | 24.0 | ••.• | 2.26 | 30.0 | 42,206 (77%) | 2818 | |
| .224 | 62gr | Hornady FMJ | 16.0 | ••.• | 2.26 | 30.0 | 49,792 (91%) | 2746 | |
| .224 | 62gr | Hornady FMJ | 16.0 | ••.• | 2.26 | 30.0 | 43,758 (80%) | 2638 | |
| .311 | 150gr | Barnes TSX BT | 25.0 | ••.• | 3.08 | 56.0 | 50,475 (95%) | 2795 | |
| .311 | 150gr | Sellier & Bellot SP | 25.0 | ••.• | 2.97 | 56.0 | 42,699 (81%) | 2671 | |
| .311 | 150gr | Barnes TSX BT | 25.0 | ••.• | 3.08 | 56.0 | 42,711 (81%) | 2664 | |
| .311 | 150gr | Barnes TSX BT | 25.0 | ••.• | 3.08 | 56.0 | 38,183 (72%) | 2575 |
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