- Model: Sig Sauer M400 Snake Bite
- caliber: 5.56×45 NATO
- Barrel: 16″ Stainless Steel Barrel
- Handguard: 13″ M-LOK Handguard
- Trigger: Single Stage Polished/Hard-Coat Trigger
- FDE Cerakote Upper and Lower Receiver
- Stock: FDE Magpul SL-K Stock
- Ambidextrous Controls
- Magazine: One 30-Round Mag
The Sig Sauer M400 Tread Snakebite 5.56 NATO 16in Cerakote Elite FDE/SS Rifle (RM400-16B-TRD-SB) is a step in the right direction when it comes to high quality AR15 platform rifles.
SIG SAUER is pleased to announce the expansion of the M400 TREAD series of rifles with the introduction of the M400 TREAD SNAKEBITE SE. The new TREAD Snakebite SE offers the same features of the amazing TREAD Snakebite model with some added upgrades.
The unique Flashhider/Compensator combo provides minimal flash and reduced muzzle rise, a two-stage Matchlite trigger delivers an ultralight trigger pull for increased accuracy and the Cerakote finished receivers and barrels offer maximum protection.
The SIG M400 rifle is a direct impingement rifle with a rotary bolt mechanism capable of semi- automatic fire operation. The rifle is chambered in 5.56x45mm NATO and is compatible with .223 Remington ammunition.
The SIG M400 has a MIL-STD 1913 rail on top of the upper receiver. The TREAD and PRO versions are fitted with an aluminum handguard with M-LOKTM attachment points.
There are eight steps in the cycle of operation of the SIG M400 which begin after a loaded magazine is inserted into the firearm.
As the bolt carrier is released from its rearward position, the carrier group moves forward allowing the lower lugs of the bolt to make contact with the rear of the cartridge as it sits in the magazine.
The cartridge is stripped from the magazine and begins its forward movement toward the chamber.
As the bolt moves forward the bolt locking lugs move forward into the barrel extension. The ejector is then compressed against the left side of the cartridge head.
The last action that occurs is the extractor snapping over the rim of the cartridge case.
The movement of the bolt and the cartridge is stopped by the chamber.
bolt carrier continues to move forward until it is stopped by contact with the rear face of the barrel extension.
As the carrier goes through the last portion of movement, the bolt is rotated to the left, through the action of the cam slot in the carrier and the cam pin through the bolt.
This engages the bolt lugs with the barrel extension lugs to lock the bolt into the barrel extension.
The selector is rotated to the Semi position.
The trigger is pressed and the hammer is released. The hammer spring drives the hammer forward unlocking the firing pin. The firing pin strikes the cartridge primer, causing detonation.
As the bullet passes the gas port in the barrel, a small amount of gas is bled off, traveling up though the gas port, into the gas block and through the gas tube. This gas drives the bolt carrier rearward. The rearward movement of the carrier causes the bolt cam pin to rotate the bolt to the unlocked position.
As the bolt carrier assembly moves rearward the spent case is pulled free from the chamber by the extractor. The twisting motion of the bolt aids in the extraction from the chamber.
The extractor continues to grip the rim of the spent case on the right side. The ejector is applying forward pressure to the left side of the case. As the expended case clears the chamber, then the barrel extension, it is flipped out through the ejector port on the right side of the receiver.
The rearward movement of the bolt carrier overrides the hammer, forcing it down into the receiver and compressing the hammer spring, cocking the hammer in the firing position.
Like all AR-15 TREAD models, the Snakebite SE works with the complete line of TREAD accessories.