I have one. Does anyone know the history behind them? Was it just a development rifle that was never meant to be sold to the mass market? (I don't think it is found in any catalog. People give it a "1600" series label, but not official i believe.) Am i correct? How many were made? Where can i get parts?
Yes, the history is well known. It was not a prototype that escaped the factory; some 30,000 were made from 1976/77 to 1980, when the first 18xx rifles appeared.
The X/1600 guns represent a stage in Anschutz's attempts to improve accuracy in the Match 54. The first X guns appeared in the mid-late 1970s around 1976 or '77 and completely replaced the wing-safety Match 54 bolt. By that time the Match 54 had been in production for over twenty years, and had seen some small tweaks, a second bolt claw added, separating the indicator pin from the bolt, adding more steel behind the left-hand ejector lug, a second barrel retaining pins etc.
The X-guns represented a much more comprehensive and calculated revision. I don't know of any changes to the barrels, although these do appear to have been made of good steel, and the average quality seems to have been high. There are rumours in the UK that British steel was used, but I've never seen any good source for this. It's not impossible though; Hammerli advertised the use of special British steel barrels on their smallbore rifles during during the '50s and '60s.
The improvements were to the ignition and trigger. Anschutz lightened the firing pin to reduce travel time, which also permitted a reduction in the strength of the main spring, which created less vibration in the barrel. To add oomph the small spring around the indicator pin was made much stronger than on 1400 M54 bolts. The ratchet end-cap increased tension on the springs compared to the old bayonet fitting. Anschutz also cut a slot in the underside on the bolt along the guide groove for the ejector stud, that exposes the firing pin; the idea was to prevent the firing pin acting as a piston and being slowed by air compressed ahead of it. A completely new trigger was developed that could be safely adjusted very light, and was much more user-adjustable than the 1407-U9 trigger. It was a two-stage, but could be set to single stage; 1611 rifles had a single-stage only version from the factory.
The familiar cranked bolt handle was introduced during 1600 production, sometime in 1978 or '79.
At the time Anschutz did not change their sales literature and continued to marked the X-barrels as 1407/1411/1413 Match 54s, and barrels were still stamped "Anschutz Modell Match 54". However an X was added to the end of the serial number to identify the new rifles, which Anschutz have said stands for eX
perimental. The 16xx designation is now common, and used by Anschutz themselves, to differentiate the various Match 54 and 18xx rifles.
The 1800 guns are themselves a development of the 1600s. The trigger is essentially the same, except the for shape of the catch, and the addition of a coarse weight adjustment cam. The firing pin was made even lighter, and as was the mains spring, but the secondary spring was made stiffer. This arrangement has remained to today, with small modifications for the 54.30. The slot in the bolt was abandoned as it allows crud into the bolt, but the inside was made large inside.