Maybe the factory made a distinction that the US importer didn't bother about. Here in the US, the stamped-receiver and milled-receiver guns are both called m/76. Maybe they called the milled guns m/83 at Tourula and the importer just called everything an m/76. Or perhaps there is some other variation that was noted at the factory but ignored by the importer. I've always wondered why the two different rifles had the same model number. (edited for error correction)
If you shoot it, that will drop the value hundreds or even thousands of dollars. I agree that you should shoot your other rifles. A rife like this in new condition is a museum piece!
The poll that is shown at the top of this page (Did Valmet make the m/71 in 7.62x39?) has no simple answer. The original m/71 was built as a simplified, less-expensive military rifle for reserve forces. It was basically a Kalashnikov AKM, without the aperture sights and improved gas system of the rk/62. It was a full-auto weapon, chambered for 7.62x39. Not many were made. The design was recycled as the semiauto m/71S, which as far as I know was made only in .223/5.56 NATO. There may have been a few made in .222 for the French market. I have been collecting Valmets for 25 years and I have never seen or heard of a semiauto, civilian-sale m/71 in 7.62x39.
