The problem of improperly heat-treated small parts In Spanish artisanal shotguns was (and is) not limited to any given date range or specific maker, or range of price points.
To understand why this is so requires an understanding of how the artisanal shotgun makers do the business of assembling and selling shotguns.
Here is a quick thumbnail overview.
A Spanish artisanal shotgun maker will not begin making a shotgun until he has a shotgun order that describes the characteristics of the shotgun the customer wants made and a sizable deposit of the finished shotgun.
With an order and deposit in hand the maker collects the parts that will be needed to assemble the ordered shotgun. By and large, the shotgun makers do not make their own parts and parts assemblies. Rather they depend on an extensive layer of small businesses that specialize in the making of some small part or parts assembly for the parts they will hand fit to produce the shotgun ordered by the customer.
The shotgun makers are sized, as a business, to have the number of people with the required skills to produce a limited number of shotguns a year. A small business may produce less than one hundred shotgun a year, a larger business may produce a few hundred shotguns a year.
The underlying layer of parts makers is just big enough to support that level of shotgun production. This layer of parts makers is inflexible and does not scale up or down very well.
And that inflexibility is the origin of improperly heat-treated parts. When shotgun makers get orders from retailers for more shotguns than they are sized to produce delivery times get long and part suppliers get orders they have trouble delivering.
This is the point at which whatever passed for what we would regard as quality control at the parts makers starts to go south. Some of the parts they make are poorly heat treated (or not heat treated at all) before delivery to the shotgun makers.
That’s how soft parts get into Spanish artisanal shotguns. No maker or price point is immune. There are no time periods when this cannot happen. It can happen whenever the level of demand for finished shotguns goes above the level of demand for parts that can be comfortably delivered.
Can shotguns with soft parts be avoided, or made right? Yes. It just takes knowledge, attention to detail, and access to a gunsmith willing and able to deal with any problems detected.
Do I want people to be unconcerned and buy Spanish shotguns? No. I collect and shoot used Spanish shotguns and the fewer people buying Spanish shotguns the fewer competitors I have at the auctions where I feed my collection of Spanish shotguns :-)