by Max Barry

Latest Forum Topics

Advertisement

3

DispatchAccountMilitary

by The Felsinsel Anocracy of The Death Syndicate. . 82 reads.

SPIRE R31

Fritz & Keitle, in cooperation with the Felsinsel Royal Military, presents to you their submission to the Special Purpose Infantry Rifle Enhancement [SPIRE] program, the Repetiergewehr 31!
Six repeating shots ring out, so closely together they sound as if one. With a dense, rifle accurate grouping fired in a salvo, hit probability is greatly improved and a moving target even with a decent degree of lead error.

Thanks to Slagenseter forn for yet another great drawing!

The Special Purpose Infantry Rifle Enhancement program has produced the Repetiergewehr 31, a very unique caseless assault rifle chambered in a modified 5.7mm F&K. The modification to the cartridge being the replacement of the triangular polymer case with a telescoped block of high intensity propellant, of course. Despite its large magazine, it is kept relatively lightweight with a mostly polymer design with thin sections of ribbed stamp steel used to improve its structural integrity. An interesting thing to note is that the ammunition itself lacks a traditional contact primer, and the lack of a traditional bolt, which will be explained shortly.

The first goal of the rifle was to create a hyper-burst weapon unlike any before it, made achievable by the lack of a case to eject. To do this, six chambers vertically stacked similar to an antiquated harmonica gun are placed on an angled track. Upon firing, the barrel recoils backwards with the aid of a muzzle booster and a gas expansion sleeve that extends over the barrel to aid in trapping gas to further push the barrel back. As the barrel goes back, it forces the slide down and thus another cylinder is aligned with the barrel and it is fired once more, and this cycle repeats without stopping until all six rounds are fired an the barrel has recoiled all the way back, whereas the shooter finally feels the recoil impulse.

The ammunition is caseless, and thus to improve the barrel seal the chambers all have a subtle lip that expands ever so slightly when the round is fired. To ensure this, a gear runs along a separate toothed track parallel to the recoiling barrel. The gear is of a oblong shape although it is driven by a parallel gear for obvious reasons. The unique geometry of the oblong gear is used to push in the chamber at set intervals in accordance with the recoiling of the firearm and acts as a means of locking it. In addition, the gear is also used to prime a hammer mechanism that strikes a small piezoelectric igniter at the back of each chamber instead that detonates a chemical primer instead of a mechanical impact igniter, allowing the ammunition to be made more robust.

The process by which the mechanism reloads is also unique, as it feeds from six 38 round box magazines stacked up on top of each-other, with the bullets laying horizontally and thus perpendicular to the chambers. The slide follows a different track back up to where the six cylinders are aligned with the magazines. The process of orienting the round to match the chamber is done when the entire mechanism is going back, however. A soft rubber pusher gets toggled by a cam and lever mechanism, pushing the top round out of the feed lips. From there, a soft roller slightly adjusts the angle of the cartridge too that the base is facing the appropriate direction, whereas a rubber slide then pulls the cartridges back along the roller and finally into the position where it can be fed into the six chambers, which rise up on the second track, move forwards unto the cartridge, loading it, and then finally falls downwards back into alignment with the barrel where the cycle can repeat.

The semi automatic fire mode is achieved with a series of notches in the track and a small retainer to prevent the hammer from dropping. When all six chambers are expended, the mechanism rocks forwards as if it has completed a burst. Sustained fire is not an option for the mechanism, however, bursts can be fired in rapid succession and due to volume of fire their hit probability is greatly improved.
Due to the location of the magazine being on top of the barrel, using traditional sights would result in great overbore. Instead, a periscopic variable zoom red dot is used, with a base 1.5x magnification and a second lens can be quickly slotted in place by simply pushing down the spring loaded lever until it clicks into place where as the magnification is increased to 3x.

To reload, a latch is slapped (yes, slapped. Why? It's a wartime firearm, if it can't survive a slap then it won't survive the trench.) open, causing the magazine to swing outwards and a rubber dust cover to be put over the feeding mechanism itself, so it does not jam. The old magazine is take out and placed back into its pouch/satchel, and a new one is inserted into place and it's disposable (biodegradable) polymer dust cover (Dirty caseless ammunition would not be good for the firearm) is popped off. Then, the panel is closed, the latch engages, and the user pulls back the chambers independent of the barrel and lets the assembly slam back forwards, achieving the same effect as a burst cycle without fighting the main recoil spring acting on the barrel.

RawReport