The term Pre-64 has been irrelevant since 1992 when Winchester brought back CRF rifles. The only reason Pre-64 was important between 1963 and 1992 is because that was the only way to get a CRF Winchester. Most of those rifles were nothing special other than that.
There are differences between the models.
The pre 64 actions have milled in feed lips. In this picture, I show a P1914 with milled feed lips in the receiver and a M70 FN Special Police Action. This was one of the last M70's made in New Haven.
this is a personnel gripe of mine. The feed lips are omitted because it is cheaper to rely on magazine boxes for feed. And, Winchester makes lots of money selling extra detachable magazine boxes. However those flimsy stamped feed lips are not as durable, nor as precise, as milled feed lips. When bolt guns ruled the NRA Highpower firing line, it was common for competitors using M700's and post 64 M70 actions to have misfeeds because the darn sheet metal magazine box feed lips were shifting around, or got bent. Shooters today don't shoot their bolt guns rapid fire like we used to, and so, feeding systems have gotten even less reliable.
Box magazines do mean you don't have to shuck out all the rounds. I have no idea why FN never made ten round box magazines for their redesigned M70.
I preferred the original M70 over ride trigger for reliability. Over ride triggers have gotten more delicate and prone to get out of order with the decades, the M70 was one of the earliest, and one of the best.
However, once the trigger was adjusted to two and a half to two pound trigger pulls, the mechanism would jar off, or "follow" during bolt closure. I suppose the lever angles could have been adjusted in a new design, but FN decided to go with the trigger mechanism in a box. Which does allow more precise alignment of parts, and also will fill with junk and water. The simpler mechanism were harder to get out of order, and I like that. I did put Jewel triggers in my target M70's, but competitive shooters go home at the end of the day, and are able to use air compressors to blow the gunk out.
The current 70's are pretty darn good too but since 2008 they have tweaked the design somewhat. But If I were looking for a rifle to use, I'd still have any of the CRF rifles made since 1992 over a Pre-64. If I had a Pre-64 with family history, it wouldn't be for sale. But I'd not pay a premium for one either.
One very significant improvement FN did was extending the bolt shroud so it blocks gas going down the left rail.
gas will still flow down the firing pin shaft, but it is an improvement over the pre 64's and US Repeating Arms M70's. Incidentally, the bolt, firing pin, will not interchange between my FN M70's and the pre 64's, and I think, the FN bolt and firing pin will not fit my US Repeating Arms M70's.
US Repeating Arms built stinkers. This is a good right receiver rail, on a USAR rifle
this is a bad right receiver rail
the "scalloping" you see at the feed ramp causes rounds on the left, to nose dive into the barrel extractor groove on the right. The bullet tip moves too far right and does not have enough time and distance to straighten out. The straight rail keeps the bullet tip inward, and it feeds perfectly. That scalloping is a factory defect and cannot be fixed, and it made that rifle a single shot only. Look for that, and avoid USAR rifles with this defect.
I still prefer the M70 over other actions, even the FN models are smooth and slick actions. Whether the little differences between models is worth a bucket of spit, well, the argument will continue.
