M6I

{|style="width:100%; color:#FFF;"
 * valign="top" style="padding:5px;"|

The M6I is a selective fire machine pistol and is one of the 's variants. The M6I itself has several variants, consisting of standard and up-sized models as well as models with different firing modes. The M6I is also chambered for the smaller, 11.5×34mm cartridge as opposed to the larger cartridge used in many other M6 variants, giving it slightly less power with the benefit of reduced recoil.

Design details
A selective fire pistol, the M6I possesses a selector switch allows the user to either fire semi-automatically or fully-automatically. The weapon typically uses 20-round magazines, but 10-round magazines are also available. Like the rest of the M6 series, the M6I is short recoil operated, using the recoil left by the previous shot to load the next round into the chamber. The barrel of the M6I is threaded, allowing the attaching of a. The M6I can also be fitted with various other attachments, such as tactical lights,, and detachable stocks.

Ammunition
Unlike many of the other pistols of the M6 series, the M6I is chambered for a smaller, less-powerful 11.5×34mm cartridge, as opposed to the cartridge. The 11.5×34mm is noticeably weaker than the 12.7×40mm, but possesses significantly less recoil, allowing the M6I to be more controllable in automatic fire. Regardless, as a magnum cartridge, the 11.5×34mm is quite powerful itself.

SAP HE
M6Is used by the  are most commonly loaded with  (SAP HE) rounds. Each of these rounds possesses a hardened steel jacket and is filled with a stable explosive. The hard jacket enables the round to penetrate body armor and enter the target, but is structured to deform shortly after entering in order to prevent the round from exiting the body and causing accidental casualties on the other side of the target. The explosive is then ignited by a fuse, detonating the entire projectile inside the target's body, producing a devastating wound that is crippling if not outright lethal. Each SAP HE round is labeled with a yellow-painted tip.

HEC
Another, less common military cartridge variant is high-explosive concussive (HEC). Unlike the SAP HE round, the HEC only possesses a copper jacket with more explosive filling, which is detonated by an incendiary material at the tip that is first ignited by the round's impact. Instead of penetrating the surface and then exploding inside the target, an HEC round creates a larger explosion at the target's surface, releasing a shockwave that stuns and disorients the target, should he/she/it survive the shot. Combined with the high rate of fire of the M6I, HEC rounds are capable of pinning down heavier infantry such as and. The explosion left by an HEC round also serves as a one-way tracer, revealing the location of shot placement while preventing the enemy from leading any projectile path back to the source. Inevitably, the HEC round is less lethal than the SAP HE round and is only effective in specific applications, warranting its relatively limited use in the UNSC Defense Force. An HEC round is labeled with a white-over-red-painted tip.

8.3×38mm SLAP
The 8.3×38mm SLAP is based on the 11.5×34mm necked down to accept a 8.3mm sabot encasing a 5mm Staballoy penetrator. The sabot allows for a smaller, lighter projectile in a relatively large cartridge, resulting in a significantly higher velocity and sectional density when fired. The dense, high-velocity projectile offers very effective armor penetration capabilities, exceeding those of the and even the. Also due to its high velocity and light weight, the 8.3×38mm SLAP possesses a much flatter trajectory when fired, resulting in a greater effective range and better accuracy compared to those of more-standard rounds. Furthermore, Staballoy is pyrophoric, combusting easily at high temperatures. As a result, the 8.3×38mm SLAP is effective at destroying lightly-armored vehicles such as and ; once it pierces plating, it can ignite fuel with the possibility of detonating the entire vehicle. As the cartridge possesses the same overall dimensions as those of the 11.5×34mm, the only adjustment to an M6I that would need to be made in order to accept the 8.3×38mm would be a simple barrel swap.

8.3×38mm Subsonic AP
The 8.3×38mm Subsonic AP is intended specifically to be used in conjunction with suppressors in order to produce as little sound as possible when fired. With the projectile traveling at less than the speed of sound, no sonic "crack" is produced. Inevitably, the 8.3×38mm Subsonic AP travels at lower velocities than other rounds do. In order to retain as much energy and momentum as possible, the projectile consists of a dense tungsten core jacketed in cupronickel. Like the 8.3×38mm SLAP, the 8.3×38mm Subsonic AP possesses the same overall dimensions as those of the 11.5×34mm, so the only adjustment to an M6I that would need to be made in order to accept the cartridge would be a barrel change.

Variants
The M6I is available in a few additional configurations, each with a distinct model name.

M6I/U (U—"up-sized")


 * The M6I/U is a larger, up-sized variant of the M6I, possessing a longer grip, allowing it fit in the hands of a wearing .  The weapon performs exactly the same as the standard variant does otherwise.

M6I/B (B—"burst")
 * Unlike the standard M6I and the M6I/U, the M6I/B has a five-shot burst mode in place of the fully-automatic function.

M6I/BU (BU—"burst, up-sized")
 * The M6I/BU is the up-sized variant of the M6I/B. Like the M6I/US is to the standard M6I, the only difference an M6I/BU has from an M6I/B is a longer grip that enables the former to be wielded by a SPARTAN wearing MJOLNIR armor.

Trivia
8.3×38mm Bullets, It Had a Modified Slide that was black and red, & A Flashlight & A  Supressor.
 * There are several notable users of the M6I.
 * Dom-094 often used a customized M6I/B as his sidearm. Throughout most of his career, his customized M6I/B was rebarreled for 8.3×38mm rounds, and was attached with a, a smart-linked red dot sight, and a tactical light.
 * However, starting October 2558, Dom-094 began using an M6I/BU loaded instead with HEC rounds, and fitted it with a different set of attachments consisting of a and a  scope.
 * Fred-G068's sidearm of choice is a customized M6I/U fitted with with a and a tactical light.  Fred-G068 carries a detachable stock separately, and may or may not attach it to his M6I/U, depending on the situation.
 * Alex Oxley uses an M6I/U rebarreled for 8.3×38mm rounds as his sidearm. His M6I/U is fitted with a suppressor, a  sight and a detachable stock.
 * Lloyd Harris uses an M6I/U as his sidearm.
 * Reginald Harding carried a pair of M6I/Us from the last year of the and onward.
 * I consider the  analogous to the present-day .45 ACP, the former of which is a large, standard-issue handgun cartridge, and the latter of which is a relatively large handgun cartridge that is standard-issue in many modern militaries.  I decided to make up a handgun cartridge for the UNSC that would be analogous to the smaller, present-day 9×19mm Parabellum.  I settled on basing the dimensions of the cartridge off those of the real-world .454 Casull, as the 12.7×40mm’s dimensions are very similar to those the real-world .500 S&W Magnum.  In terms of dimensions, the 11.5×34mm differs from the .454 Casull in that its case is 34mm long as opposed to being 35mm in length, very much like how the 12.7×40mm’s case is 1 mm shorter than the .500 S&W Magnum’s.  Another difference between the M6I's 11.5×34mm and the .454 Casull is that the former is rimless while the latter is rimmed.
 * The properties of the 8.3×38mm SLAP cartridge is based on those of the 6.5×25mm CBJ Ball cartridge, which can pierce armor more effectively than the 7.62×51mm NATO (likely M80 FMJ) can.
 * Jack Faren Owned A Modified M6I SOCCOM That fired 11.5×34mm Bullets Instead Of