Mauser rifles were an evolving product into the early part of the 20th century. A few things one can look for.. The M93 dpesn't lock the bolt handle root into a notch in the receiver, The earliest versions had a square edge on the bottom of the bolt face. Later ones were rounded. The M94 introduced an anti bind rail/lun running the length of the off side of the bolt. The M95 included the feature where the root of the bolt handle rotated down into a notch in the receiver. This added a 'safety lug' of sorts should the primary locking lugs fail catastrophically. The 98 added the third lug on the rear of the bolt body that fitted into a mortise in the rear receiver ring, without touching it. There were other additions and many, many vaiations including floor plate differences, cocking piece shapes and others. In general 93-96 mausers were small ring(outside diameter of the front receiver ring) and small barrel shank diameter. The M98 a large ring, large barrel shank diameter. The small receiver ring was used on certain M98 actions also and there is also an intermediate length action... Very confusing.. If the front ring is the same outside diameter as the rails connecting it to the rear receiver ring it is likely a small ring,,if the bolt lacks the 3rd locking lug or safety lug of the M98 it is likely a M98 variant.. If the action you have is pre M98 most smiths reccommend barreling to calibers with more modest pressure limits such as the 7x57 or the small 250 Savage.. Also many smiths won't work with the mauser variants made in Spain(such as yours) at all. The pre-M98 actions don't have the bect gas handling properties and in case of a primer leak or case head rupture the user could well be injured. Just as an asside the pre64 M70 also is poorly designed for handling the sudden release of high pressure gas as are the M700 action when the sako/M16 extractor is installed... We also didn't discuss the earlier M90-91 action as it didn't incorporate the staggered box magazine of the non-rotating extractor. Both of which combined with its early production usually limit its use in sporting rifles by modern smiths. I have found the Spanish built mauser to be quite poorly made and maintained. The South american rifles also usually have many condition problems but were in the main made in Europe. The Swedish nuilt M94-96 rifles(including the M38) were well built of very good steel and well maintained. Some of these rifles are amazingly accurate..but their increasing values is starting to limit their availability for use as sporters. When sporterizing a mauser it is wise to limit yourself to a well built version of the M98. These actions can be had still today for under $100(sometimes much under). They are the best choice of technoledgey as a place to start. I have used E.R.Shaw and while it's not likely I would use one of his barrels on a premium rifle or a match gun, they have all been more than accurate enough for hunting.. Be aware this is a far cry from a comprehensive listing and many, many exceptions and variations exist, some not too rare!!
