many of the Mausers were refitted to Springfield 03A3 stocks with side grooves, but most aftermarket stock companies make stocks for this 23" bbl setup. Does yours has "L" space "C" on the stock right behind the bolt?
Most of these 7mm's were re-chambered into 7.92x57 in 1943 in La Coruna or Oviedo, Asturias, to match the M43 coming out. Is yours 7 or 8 mm?
The re-chambering from 7 x 57 mm to 7.62 NATO was done during the 1960's and the rifles then issued to Spains 'Guardia Civil'. This is a sort of national police force.
The 1916 rifles come in several variants, some marked with the arsenal and royal crest - others with absolutely no markings at all. Both are commonly seen.
These 'Guardia' rifles have a 21" barrel and fit the 1893 pattern, so they are considered 'small ring' Mausers. This also means that you can expect to do some fitting to whatever stock you obtain. I know Ram-Line sells a black plastic stock for these small ring actions, and Boyds a wood stock. The latter surely requires fitting.
By the way, there is much ado made of the 1916 actions ability to handle full power .308 WIN ammo. There are pressure differences between the intended NATO and sporting ammo, thus:
49,700 psi CUP - 7.62 NATO
52,000 psi CUP - .308 Winchester
Many people discount this difference as meaningless and shoot full house .308 ammo in their 1916's. Others err on the side of caution and don't shoot anything but NATO milsurp or reduced hand loads. Given the age of the rifle and the original intent, I would go with the latter scenario more than anything else.
A few rounds of full pressure .308 probably wont hurt, but approach that with caution. Make sure your gun has been examined by a competent gunsmith before you do.
But lets face it, the 1916 Spanish is a smallish, short barreled rifle chambered for a powerful cartridge. Loaded to NATO pressures, you step just beyond the venerable .300 Savage - the round which gave birth to the 7.62 NATO in the first place. You can easily get 2600- 2700 fps from it and still stay well below NATO pressures.
In return, it will -
A. Kick you out of your tree stand,
B. Blast any vegetation within 6 feet to shreds
C. Take any deer you run across and most other game, to boot.
So what point is there in adding more pressure, blast and recoil to that?
Back in the 50's and 60's it was comon for guys to take down old military rifles and cut down and modify the stocks, barrels,and other components. By doing so many a valuable1903 springfield or enfield was taken from being an $800 or $900+ military collectable, and was turned int a $300 beater. I am not saying " Don't do that!!!", but atleast keep the original parts stored away incase you one day wish to return it to factory condition. My uncle and grandfather both sporterized thier 1917 enfield and 1903 springfield mark one,and to this day they regret throwing away the military parts. Thank god the old man left his arsaka alone! I myself have a 1916 Spanish short rifle in 7x57 and am looking for a second stock for it. If you find an aftermarket stock for yours let us know what company sells it and how well it fits. Best of luck and I hope you enjoy what I have found to be a fun little rifle for hunting and target use.