18″ SOTM5 .308 WINCHESTER PRS RIFLE, FDE CERAKOTE®
A large-frame rifle specified one part at a time.
$3,200.00 SKU RFL-M5-308-B180-FDE
This SOTM5 is an 18″ .308 Winchester rifle built on Second of Ten’s billet SOTM5 receivers: a thermal-fitted MOD-0 upper over a 7075-T6 aluminum lower. The barrel, gas system, bolt, recoil parts and controls are each chosen for this cartridge and this role, and each is named below. Upper, lower and handguard are finished in FDE Cerakote®, with black Magpul furniture.
A note on the name
SOTM5 names the rifle; the serialized part is the lower receiver. MOD-0 names the billet upper fitted to it, here in its no-forward-assist configuration. PRS identifies the stock configuration, built with the Magpul PRS® GEN3.
//The Barrel
The barrel is the part of this rifle that most decides how it shoots, so it is the part chosen first. Second of Ten fits the Faxon Duty Series 18″ .308 Winchester barrel in the Gunner profile, and these are the features of it that matter.
//The Handguard
A free-float handguard only helps if it stays where it was put. The 15″ SOT Wedge-Lock M-LOK® handguard is built around that.
//The Case
The barrel comes first
18″ Faxon Duty Series .308 Winchester barrel in the Gunner profile: 4150 CMV, button rifled, 1:10 twist, QPQ nitrided, rifle-length gas. The rest of the rifle is specified around it; the detail is set out above.
A thermal-fitted billet upper
The SOTM5 MOD-0 upper is machined from 7075-T6 aluminum billet to the LR-308 DPMS high pattern, with laser-engraved T-marks and a dry film lubed interior. It is thermal fitted to the Faxon barrel, so the joint between barrel and receiver is an interference fit and not a slip fit.
No forward assist, by design
This rifle uses the no-forward-assist configuration of the MOD-0, with the forward assist bore closed by a threaded forward assist pin. The upper is otherwise identical to the MOD-0FA.
Gas you can set, on a block that cannot move
A RIFLESPEED adjustable gas system lets the rifle be tuned to the load and to a suppressor. The gas block is pinned to the barrel with a steel coil spring pin, in line with the Bombproof by Design™ philosophy.
A bolt group for the LR-308
KAK Industry LR-308 bolt carrier group with a double-ejector bolt: 8620 steel carrier with its rails, bolt run and gas bore ground to .0002″, a 9310 steel bolt in phosphate, and a heat-treated 4130 gas key on Grade 8 fasteners, hydraulically staked. MPI tested and marked (KAK).
Caliber marked on the cover
The ejection port dust cover is engraved .308 WIN, so the caliber reads at a glance with the cover closed.
A two-stage trigger, left as made
Geissele Super Semi-Automatic Enhanced® (SSA-E®) two-stage trigger with the M4 curved bow: about 2.0–2.5 lb first stage and 0.9–1.3 lb second stage, 2.9–3.8 lb in all (Geissele). Second of Ten does not stone, polish or alter sear engagement surfaces.
Controls on both sides
Ambidextrous bolt release, with a paddle-style oversized bolt catch on the left and Second of Ten’s own serrated release button on the right. Extended left-side magazine catch release with a right-side button. Breek Arms WARHAMMER Mod2 charging handle in FDE, with oversize latches on both sides.
A selector you can set to 45° or 90°
The Radian Weapons Talon® 45/90 ambidextrous safety selector runs as a standard 90° selector or as a 45° short throw by rotating the shaft 180° inside the lower. It is installed and configured at 90° and can be reconfigured by the end user.
A buffer that takes energy out
A KynSHOT RB5006 hydraulic buffer and the JP Enterprises tuned and polished buffer spring, in a rifle-length receiver extension. A hydraulic damper converts some of the carrier’s energy to heat rather than storing it. KYNTEC builds the RB5006 in 17-4 stainless for AR-10 rifle-length fixed-stock tubes, rated −30°F to +150°F, and says it helps prevent bolt bounce.
Tension where the halves meet
The billet lower carries an upper receiver tension screw, a threaded bolt catch pin and a rear takedown detent spring with set screw, with Battle Arms Development enhanced AR-308 steel pivot and takedown pins.
A stock made for shooting from position
Magpul PRS® GEN3 precision-adjustable stock, with tool-free aluminum knobs for length of pull and comb height and positive click detents, and a Magpul MIAD® GEN 1.1 Grip Kit, TYPE 2, both in black.
//Inspect It Yourself
This rifle has a zoomable inspection page showing both sides of the rifle as built, so the markings and machining can be read from the photograph instead of taken from a spec table. The serial number is blurred; no other marking is altered.
Open the viewer → SOT_SOTM5-18-308-PRS_FDE_Rifle_Zoom_Viewer.html · SOT-WEB-RFL-047
ZOOM 5×
//Specifications
- Model
- SOTM5 · 18″ PRS rifle
- SKU
- RFL-M5-308-B180-FDE
- Chambering
- .308 Winchester · runs 7.62×51 NATO
- Overall length
- 40″
- Weight
- 9 lb 9.14 oz
- Barrel
- 18″ Faxon Duty Series, Gunner profile · 1:10 right-hand twist · 4-groove button rifled · 18.13″ · 2.13 lb
- Barrel steel and finish
- 4150 CMV steel · salt-bath QPQ nitride, bore and exterior · 100% wet magnetic particle inspected
- Chamber
- .308 Winchester SAAMI, CMM-checked · headspace 100% checked with a go/no-go gauge (Faxon)
- Barrel extension
- DPMS Gen 1 pattern .308 · black oxide · torqued to 150 ft-lb and pinned by Faxon
- Muzzle
- Threaded 5/8×24 · target crown · Faxon Gunner 7.62 MuzzLok® 3-port brake, removable · direct-thread suppressor ready with the brake removed
- Gas system
- RIFLESPEED adjustable · gas block pinned to the barrel with a steel coil spring pin · rifle length · .093″ port · .750″ journal
- Handguard
- 15″ SOT Wedge-Lock, M-LOK®, free float · FDE Cerakote®
- Handguard construction
- 6061-T6 aluminum · 1.45″ inside diameter · tri-lug clamp · full-length top Picatinny rail · M-LOK® on seven sides · steel HD barrel nut · Grade 8 hardware · 14.4 oz
- Upper receiver
- SOTM5 MOD-0 billet, no forward assist · 7075-T6 aluminum · LR-308 DPMS high pattern · threaded forward assist pin · laser-engraved T-marks · dry film lubed · thermal fitted · FDE Cerakote®
- Charging handle
- Breek Arms WARHAMMER Mod2, AR-10 / LR-308 · FDE · oversize ambidextrous latches
- Dust cover
- Engraved .308 WIN
- Bolt carrier group
- KAK Industry LR-308 · 8620 steel carrier, rails, bolt run and gas bore ground to .0002″ · 4130 gas key, Grade 8 fasteners, hydraulically staked · 18 oz
- Bolt
- 9310 steel · phosphate · double ejector · MPI tested and marked (KAK)
- Lower receiver
- SOTM5 billet, marked MULTI · 7075-T6 aluminum · Type III hard anodized · FDE Cerakote® · upper receiver tension screw
- Lower details
- Threaded bolt catch pin · rear takedown detent spring with set screw
- Trigger
- Geissele Super Semi-Automatic Enhanced® (SSA-E®), two-stage, M4 curved bow · about 2.0–2.5 lb first stage, 0.9–1.3 lb second, 2.9–3.8 lb in all (Geissele)
- Safety selector
- Radian Weapons Talon® 45/90, ambidextrous · configured at 90°
- Takedown and pivot pins
- Battle Arms Development enhanced AR-308 pin set · steel
- Bolt release, left
- Paddle-style oversized bolt catch
- Bolt release, right
- SOT proprietary, serrated
- Magazine release
- Ambidextrous · extended left-side release · right-side button
- Receiver extension
- Rifle length · black anodized
- Buffer
- KynSHOT RB5006 hydraulic, 17-4 stainless
- Buffer spring
- JP Enterprises tuned and polished
- Stock
- Magpul PRS® GEN3 precision-adjustable · black
- Grip
- Magpul MIAD® GEN 1.1 Grip Kit, TYPE 2 · black
- Magazine
- Magpul PMAG® 20 LR/SR GEN M3™, plain, included · magazine shown in photographs may differ
- Options
- Magpul MBUS 3 front & rear sights, +$75.00 · Lancer Systems Gen 2 L7AWM® 20-round magazine in Translucent Dark Earth or Translucent Smoke, in place of the standard magazine, +$20.00
- Finish
- FDE Cerakote®: upper, lower and handguard · charging handle FDE · stock and grip black
- Price
- $3,200.00
//Notices
Set the gas for the load
The adjustable gas system should be set for the ammunition in use and reset when a suppressor is fitted or removed. A setting that suits one load is not necessarily right for another.
The selector is set at 90°
The Talon® 45/90 selector ships configured as a standard 90° selector. It can be changed to a 45° short throw by rotating the shaft 180° inside the lower receiver.
Photography © Second of Ten LLC. Battle Arms Development, Breek Arms, Faxon Firearms, Geissele Automatics, JP Enterprises, KAK Industry, KYNTEC, Lancer Systems, Magpul, NIC Industries, Radian Weapons and RIFLESPEED names and marks, including Cerakote®, KynSHOT, MuzzLok®, SSA-E®, L7AWM®, M-LOK®, MIAD®, PMAG®, GEN M3™, PRS® and Talon®, are the property of their respective owners. Their appearance indicates that Second of Ten incorporates the component, not sponsorship, affiliation or endorsement.