This is an exceptional example of a very rare early post-war Swiss Model U semi-automatic experimental/prototype rifle serial number 78. It has an all blued metal finish with a beautiful European walnut stock and handguard. This series of rifles was actually developed shortly after WWII when the Swiss Government was evaluating the use of semi-automatic rifles and sniper rifles. One of the models they came up was this Model "U" that used a square action and bolt designed mechanism, where the rear of the bolt tips down to lock and unlock the rifle action. It was also fitted with a detachable box magazine and a side mounted sniper scope, a.k.a. the Model 42 sniper scope. This rifle is certainly unique and a clear departure from the standard K31 rifles which used a standard round rotating bolt design. It has the standard side mounted, straight pull type bolt handle that was directly connected to the tilting breechblock. This breechblock is square in shape, as noted, and is very similar in configuration and operation to the Savage 99 rifle design in that during the cycling action the rear of the breechblock tilts or drops downward to unlock the bolt allowing it to recoil reward. Then during the reloading/cocking action the rear of the breech bolt is pushed up into battery, locking the rear end of the bolt into the rear edge of the receiver. The stock design is similar to the K31, although heavier and beefier through the mid section with a more square cross section. It is theorized that this rifle may have been used to develop/evaluate alternate semi-automatic designs for a new sniper rifle. The barrel is fitted with a military style tangent rear sight graduated "1-15" (100-1,500 meters) and a standard fixed front sight with protective ears. The noted "31/42" sniper scope is permanently attached to the left side of the receiver just like the K31 model that were also equipped with the Model 31/42 sniper scope. The scope has the standard inverted "V" aiming point reticle. The top rear section of the action cover is marked: "Schweizerische/Industrie - Gesellschaft/Nauhausen/Mod. U No. 78". The serial number "78" is also found on the rear area of the bolt and extractor. It is fitted with a full length walnut stock and one-piece handguard with finger grooves on the sides that is fitted two barrel bands and sling swivels mounted on the left side, just like the K31 rifles. It comes with one original 5 round box magazine that is marked on the base plate: "SIG/Neuhausen a/Rhr/Mod. U Kal. 7.5/ No 78/6" and an additional 10 round magazine that is marked with the same factory marking on the base plate that is numbered "78/12".

Excellent with 98% of the original blue finish overall with only minor edge and high spot wear. The complete bolt mechanism is still in the white as it left the SIG factory. The integral sniper scope also retains 98% of its blue finish with clear sharp optics. The stock and handguards are both in excellent condition with only minor handling marks on the sides and some heavier pressure dents on the front under side (behind the middle barrel band) of the stock. This is an exceptional example of a rare Swiss SIG Model "U" sniper rifle.