Some of the La Coruna actions were very brittle due to improper (mid Spanish Civil War circa 1938-39) heat treating. As such, they were very brittle and would crack if fed high pressure ammo.
The fact that it has been successfully drilled and tapped suggests that its one of the "good ones". A brittle reciever is known to "eat" carbide tap's... (break them off, that is if you could even get the drill bits to drill straight holes).
I've got one that I had reworked to .257Roberts in 1983. It was done by a friend who was a gunsmith and the metal work is exquisite/beautiful. It wears a Brownells bolt handle (a bit different from yours) and the reciever was re-milled to eliminate the raised boss for the stripper clip slot. It also was polished with a 400grit high luster/gloss blue and wears a Bishop #2 grade "semi-fancy" Walnut "feather weight" stock with Rosewood grip and forend caps. It also has extensive "point-pattern" checkering.
It has an E.R.Shaw barrel, and though it picked up some mid-bore pitting 20yrs or so ago, it still shoots sub-moa 5-shot groups.... (It wears a '60's era Leupold Vari-X II 2-7x scope). I've taken over 100 white-tail deer and a mule deer with it...
Market value probably isn't any better than yours or a used Savage Axis ($250-400.00) but sentimental value, it's priceless.... My wife, and younger brother both killed their first deer with it. My younger brother in the early '70's when the rifle was still in 8x57mm, though even then, it wasn't the original barrel which was probably shot-out before 1945.... My older brother and I bought it for $7.99 in April of 1968 before the '68 GCA went into effect. Rather I should say my mother "payed" for it at the check out at the Mason's Dept. Store in south Anniston, Alabama... They "dumped" them before the records requirement of the '68 GCA went into effect. (The infamous ATF #4473 form). They had dozens of them in stacked in metal trash-cans along with Italian Carcano's, and '93 Mausers in 7x57. Carcano's were $5.99, '93's were $6.99 and M98's (La Coruna's) were $7.99. My older brother knew enough to know the M98's were "a little better" at the time... Though in reality now, the Carcano's would sell for more...as they were in 6.5.
A co-worker of my dad was a "basement" gunsmith and put another barrel on it in 1968, as the original looked like a "rusty sewer pipe" with essentially no rifling. I remember the first time we took it out, it wouldn't even fire due to a damaged firing pin. My dad's co-worker put a new firing pin and the barrel off of a BRNO mauser he'd gotten from "Flaigs" that he had built into a .22-250 even before Remington brought it out....
It shot well with the 8x57, but was very, very UGLY !!!
It's now a family "heirloom"... That still "works for a living"...
