Most Collaths tend to come in bizarre gauges that were designed by Wilhelm Collath himself. However, some Teschner-Collath guns from the 1920's feature 16 Gauge 2 9/16" shotgun chambers, which are perfectly shootable.
Wilhelm Collath, the gun's designer, was one of several of German gun designers in the 1910's trying to take the "underlever is stronger" theory to the max. He pretty much wanted to design a gun that would never loosen. He succeeded...I've never seen a loose Collath...but at the expense of the gun's looks (at least compared to other Drillings and shotguns).
The huge underlever, sliding barrels, huge locking lug, and gas seals (known as "Collath Gaschecks") are all responsible for keeping the gun tight. An interesting safety feature of the time was the large "key safety" on the receiver tang. When the gun is set to fire, you can see the front and rear sights if you align the gun with your eye level. But you can't see the sight picture with the safety engaged. Collath drillings feature double triggers with the forward one a single-set trigger. Collath shotguns almost always have regular double triggers. On the drillings, the rifle/shotgun selector is (quite handily) right next to the triggerguard, not on the upper tang. When the selector is down and level with the triggerguard, you're on shotgun mode. When flipped forward and up, it's in rifle mode.
Wilhelm Collath himself made guns from I believe 1890-1910. In 1911, a firm called Teschner bought out Collath and continued making guns under his name until at least 1930. Teschner kept making guns until WWII.
And this is the same gun, but better photos...
http://www.littlegun.be/arme%20allemand ... e%20gb.htm
Now here's the gun I have on layaway, a September 1924 Waffenfabfrik Simson/Iver Johnson Model 36...
Notice a few things that might make it a bit more attractive to an American buyer (at least on the surface). The stock has a right-hand bent and no cheekpiece. Unlike your typical Simson drilling made for the German market, this one is also devoid of claw mounts (the German equivalent to the Model 36 had them). The barrels are also a tad longer than one might expect. In Germany, drilling barrels at the time were most commonly 26" (26.5" was also common) in length. The Model 36 was only marketed with 28" barrels. First catalogued in 1925, this gun was (as we can see on the rifle barrel) made in September 1924 and is an early, uncatalogued variant of some kind. I say this because the only rifle caliber offered with the Model 36 in the Iver Johnson Sporting Goods catalogue was .30-30 Winchester. This one, however, has an 8x50R Mannlicher rifle barrel. And then there's the tang slider, which alternates between shotgun mode and rifle mode. Most of the ones I know of for this particular model have the letters "S" and "R" for "shotgun" and "rifle." But this one has the letters "S" and "K," which is typical for German guns and stands for "schussflinte" (shotgun) and "karabiner" (carbine).
