Lead delivery systems

.375 SOCOM Bullets

The .375 SOCOM is a fairly new cartridge, designed by Tromix in 2013.  Taking a .458 SOCOM cartridge case and sizing the neck down to .375 caliber, resulted in a hard hitting AR-15 compatible cartridge, that has a considerable velocity and range advantage over the .458 SOCOM as well as other big bore AR-15 cartridges. Unknown to most, the .375 SOCOM  has a sizeable case capacity, nearly 60 grains, that is on par with the .308 Winchester.  Typical .375 SOCOM loads will launch a 200gr bullet 2400+ feet per second from an 18” barrel.  In a short barrel suppressed subsonic application, the .375 SOCOM can be made to easily cycle the AR-15 action, using fairly fast burning propellants such as Trail Boss.  This can be problematic with the .458 SOCOM when barrels are shortened below 12”.

Bowers CAC-9S (.375) Suppressor $825

Adds 1.3" to barrel length.
Available in black or stainless finish.
Black $60
Stainless $65

Includes a pre-form die, full length sizing die, and bullet seating die.

.375 SOCOM Bullets

375-LFD .375 SOCOM Lee Factory Crimp Die $35

MIG3-09 Shown

SCM10c Carbon Steel
SCM10s Stainless Steel

For indexing muzzle brake.
“Specify carbon steel or stainless”

.375 SOCOM Crush Washer 5/8” $3.00

.375SOCOM 18" Lightweight Stainless Barrel Only $299

Barrel weight: 1.87 lbs.

Black Finish - Add $25

Black Finish - Add $25

Includes complete ready-to-install 18" stainless steel barrel.  Barrel profile is .900" under the hand guards, .875" at the gas block, and .800" at the muzzle. Threaded 5/8-24 with a 1:12 twist.  Uses a mid-length gas system and requires a .875" gas block. Barrel weight: 2.40 lbs

.375 SOCOM 18" Midweight Barrel/Bolt Combo $349

Ejection port enlarged, includes forward assist and ejection port cover.
Tech Tip: To enhance feeding reliability, it is recommended to blend the barrel feed ramp into the upper receiver after barrel installation, as shown.

.375 SOCOM Upper Receiver $135

No dealer discounts on .375 SOCOM parts.
No International Shipments.

To place an order for .375 SOCOM parts please contact Tromix at: (918) 543-3456

375 SOCOM Parts

Factory .375 SOCOM ammunition is now available from both Strike Force and SBR.  Reloading dies are available from Tromix, CH4D, and Hornady.  458 SOCOM cartridge cases are available from Starline Brass, but would need to be resized to  .375 caliber using one of the above die sets. Factory .375 SOCOM ammo now available from Strike Force Ammunition. To order, call Strike Force direct at (812) 890-2678.

Upgrade your 375-18 with the MI-G3 M-Lok hand guard

Install Muzzle Break or Radial Comp instead of Flash Hider - add $30

375 SOCOM 2-die set from CH4D $135

The .375 SOCOM feeds from most all GI type 5.56 M16 magazines, however Magpul P-Mags are not recommended.  Thirty round 5.56 magazines hold 10 rounds of .375 SOCOM ammunition and 40 round 5.56 magazines hold 14.

Maker Bullets (Box of 50 bullets) - $49

These barrels are setup to run subsonic bullets using fast burning powders such as 700X, Trail Boss, N32C Tin Star, etc. Use .101 gas port for shooting with suppressor installed, or .116 port for shooting with or without suppressor. Recommended load - 10.0gr IMR 700X, 325gr Maker Expander bullet, CCI 350 primer.  1050fps.

These 9mm suppressors have been specifically modified by Bowers for use with all .375 SOCOM ammunition.

Stainless Steel, 5/8-24

.375 SOCOM Ejector $5

.375 SOCOM .875” Gas Block

.375 SOCOM Slotted Case Gauge $45

Includes complete ready-to-install 18" stainless steel barrel.  Barrel profile is .785" under the hand guards, .750" at the gas block, and .730" at the muzzle. Threaded 5/8-24 with a 1:12 twist.  Uses a mid-length gas system and requires a .750" gas block. Barrel weight: 1.87 lbs.

8.6" in length, 1.72" OD, all stainless steel, user serviceable.  Includes 5/8-24 thread adapter.


Complete assembled 18" .375 SOCOM shown with optional MIG3-12" hand guard and optional muzzle brake. $929

Available in 7.25" and 12.5" lengths. Compatible with

.458, 450, and 375 Uppers.

Typical powders for the .375 SOCOM include AR-Comp, AA2520, VV N530, VV N135, VV N140, IMR4895, Varget, Reloader 15, and H4895.  Powders intended for the .458 SOCOM should not be used in the .375 SOCOM due to their burn rate being too fast for the .375.

.375 caliber REX 325 grain copper hollow points designed specifically for expansion at subsonic velocities in the .375 SOCOM. 
(This is not loaded ammunition.  Projectile only)


Complete assembled 18" .375 SOCOM Upper $749


Mid-Length Gas Tube $15


Thread Protector, Knurled Steel 5/8-24tpi   $20

Black Finish - Add $25

Charging Handle $25

.375 SOCOM Extractor $30

.375 SOCOM Bolt Only $110

.375 SOCOM 18" Midweight Stainless Barrel Only $299

Barrel weight: 2.40 lbs.

.375 SOCOM 18" Lightweight Barrel/Bolt Combo $349


Free Float Tube Hand Guard - $65

Factory .375 SOCOM ammunition and brass are now available from SBR Ammunition  www.sbrammunition.com


Tromix .375 SOCOM 3-Die Set $89

Includes 11" stainless barrel, flash hider, picatinny rail gas block, bolt/carrier and charging handle. Ready to fire on your Pistol/SBR lower.

375-02P10-SUB - Subsonic Barrel

MIG3-15 15.0" Add $175
MIG3-12 12.6" Add $165
MIG3-1010.5" Add $145
MIG3-09 9.25" Add $135
MIG3-07 7.25" Add $125

Fully functional with 10, 20, and 30 rounds of 5.56/.223 ammunition.  No shipments of 7/20 or 11/30 round magazines to restricted locations. These Lancer 5.56 magazines have been re-machined by Tromix to allow even the most flat/blunt nosed .375 bullets to feed properly.

Stainless steel, pistol length gas system, .875 gas block journal, 1:10 twist, black finish, threaded 5/8-24. Available with .101 or .116 gas port. 
10.5" .375 SOCOM Barrel and Bolt Combo $349
10.5" .375 SOCOM Barrel Only $299
Bowers .375 SOCOM Suppressor $825

Complete .375 SOCOM Bolt & Carrier Group $205

SCM04c Carbon Steel $35
SCM04s Stainless Steel $40

4140 Steel Slim-Line Low Profile Gas Block AR-15/AR-10 .875”

​Gas Block Dimensions - .773" up from bore center, .622" down from bore center, 1.030" wide.

Manufactured by Tromix under licensing agreement with Sheridan Engineering (Pat. Pend)

Black Finish - Add $25

Tromix Radial Compensator

11" .375 SOCOM Barrel and Bolt Combo $349
11" .375 SOCOM Barrel Only - $299

Includes ejector, extractor and gas rings.

Available in 4, 7, and 11 round capacity.

Install Muzzle Break or Radial Comp instead of Flash Hider - add $30

​.458/.375 SOCOM Magazine - $20

Complete assembled 18" 1:12 twist barrel, flash hider, low profile gas block, bolt/carrier, and charging handle included. Ready to fire on your AR-15 lower.

Black Finish - Add $25

Complete assembled 11" .375 SOCOM upper $749

Stainless steel, carbine length gas system, .875 gas block, 1:12 twist, threaded 5/8-24

.375 SOCOM Flash Hider 5/8-24

SCM08C  Carbon Steel $30
SCM08S Stainless Steel $35


.375 SOCOM Muzzle Brake $65

Also available from