I'm not Vic but I have a bit of experience with the M70 along with others. What the M70 has (at least the pre-64 and, especially, the pre-war models) are some features which are perceived as being improvements and other features which are just that; features.
The first thing the M70 has going for it is that it was conceived and built as a sporter. It was made to be attractive in contour and was given a low, swept back bolt handle which was tucked out of the way yet still readily accessible.
The second thing it had going for it was the trigger. This was one of the first of the over riding sear type triggers. It was adjustable for weight of pull and overtravel. To me, the trigger becomes one of those perceived improvements. As I said before, I like a well set up two stage trigger just fine. The model 70 trigger is a good one though and is relatively easy to set up. I have M70's with triggers set under 2 pounds on which you can slam the bolt or bounce the rifle on the floor (something I seldom do with a loaded rifle, by the way) without having them fire accidentally.
Another feature which is seen as being an improvement is the change in the ejector location and the resulting change in the bolt head. In the Mauser, the ejector blade is incorporated into the boltstop assembly and the left locking lug is slotted to allow the ejector blade to pass through it. The Model 70 moves the ejector down to the lower left of the receiver bridge. The bolt is slotted through the face beneath the lug which leaves the left lug solid. The advantage? Obviously a solid lug is likely to be stronger than a slotted one. The disadvantage? The ejector on the mauser is actuated by a robust and lightly stress leaf spring. In addition it is in a relatively clean area and unlikely to accumulate crud. The M70 is actuated by a tiny coil spring and occasionally gums up with debris. So, it's a tradeoff; the slightly more reliable Mauser extractor is trade for the slightly greater strength of the M70 solid lug.
The bolt stop of the M70 is moved to a position below the stock line. This leaves a nice uncluttered side on the receiver where the mauser has the visible, boxy looking bolt stop/ejector on the left rear of the receiver. This is another area where the M70 "improvement" is only perceived. It is less sure than the Mauser. Because it disengages by being pressed down, it is possible for it to be pushed down by accident and the bolt lost (it has happened folks!). The Mauser is, again, more robust. The actuating spring is more than needed. The Model 70 may win some appearance points from those who like the uncluttered receiver look but I think the Mauser stop is a classic example of form following function and still looking good doing it.
The Model 70 trigger guard and floorplate are nice. Especially the pre-war ones. Nicely shaped guard and a floorplate with just enough metal. The floorplate latch is simplicity itself and works beautifully.
The model 70 coned breech is a stupid feature copied from the Springfield. It does nothing for safety of feeding. It's a poor feature which Winchester continued with. The Montana Rifle Company even perpetuated the coned breech in their modern action. The only difference was the cone was cast into the receiver rather than being cut on the barrel.
In the event of a case failure the cone does a great job of funneling gas and debris directly into the left locking lug raceway which directs it to the shooter's face. The Mauser's inner barrel seat (c-ring) effectively blocks off the raceway from the open bottom of the bolt face. Any gas which does head down the raceway is blocked by the bolt stop and escapes via the thumb notch.
It can be seen that the M70 has some truly positive features (appearance, trigger, bolt handle) and some features which are positive or negative depending on your viewpoint (ejector and bolt stop). It also has one which is purely negative; the coned breech.
Taken as a whole, the Model 70 was the best commercial bolt action sporting rifle ever made in the United States. It may well have been the best commercial bolt action sporting rifle in the world. There are plenty of good reasons to like the M70 but I still think, as a field rifle action, the Mauser has the edge. Ever since the introduction of the Remington 722, neither has been a truly viable accuracy action though. Regards, Bill.
