MY-14 lateral machine gun caissons

Torstai 14.12.2023 - Reino Myllymäki


The armament of VL Myrsky II consists of four synchronized heavy 12,7mm VKT machine guns, located in the front fuselage. Each machine gun has its own caisson. The machine gun caissons in the middle hold 220 and the lateral gun caissons 260 rounds.  


The VL Myrsky II restoration project has available three Myrsky fuselages (MY-5, MY-9 and MY-14). In all of them the original rails for the caissons were in place. In all these the rails were intact, but the steel parts were badly rusted. The original caissons couldn’t be found anywhere.





The MY-14 rails were picked out to be restored, dismantled from the fuselage and all the screws and rivets were taken apart. The rust from the steel parts was blown away with glass ball blasting, the surfaces were treated with Isotol-klarlack and painted grey. The aluminium parts were cleaned with glass ball blasting. The parts were riveted together again with aluminium rivets according to the blueprint, and the entity was painted grey all round. The refurbished rails were installed back to their original place.




The entirely new caissons were made according to the blueprints. The blueprints lacked the detail picture of the rear handle, the necessary measurements were obtained from the assembly blueprint. The finished caissons turned out to be slightly too big and they didn’t fit properly into place. The matter could be corrected by adjusting the rails and hammering the caissons. The left-hand caisson remained a bit ill fitting. This was mostly because the left-hand adjustment screws of the rails couldn’t be properly reached. The locking of the caissons was observed to be working.



How the caisson is fitted into place and locked: The caisson slides to place on a roller rail. The locking lever in the lower rail is turned up, and with a screw in the lever the caisson is tightened into place. The handle of the caisson is turned down and a locking peg inside the handle locks the handle in the down-position. The square-shaped tip of the locking screw leans now against the handle of the caisson and prevents the locking screw from turning on its own account. The steel front plate of the caisson is meant to guide the spent cartridges, coming from the gun above, into the collection box.


The caissons will be painted grey all over later, at the same time as other larger parts are taken to be spray painted.

Avainsanat: aviation history, restoration, MY-14, VL Myrsky