I have built and maintained a few full house target M-14 rifles with both Norinco and Springfield receivers. The Norico recivers are closer to GI dimensional specifications, so are much easier to fit US GI parts properly.
The M-14 is designed to seat the action into the stock bedding by the spring pressure of the trigger guard pulling down on the receiver. If properly set up nice and tight, this method can work well, but if too loose, it can cause some loss in accuracy. Lugged actions, as previously mentioned, can be fitted with screws, which can provide more consistent seating which may increase theoretical accuracy ...
maybe..
In the real world, the lugged receivers may not improve accuracy by much, but they will provide larger bedding surfaces to help maintain that accuracy and bedding life for longer.
Other solutions would be the aftermarket stocks which completely redesign the bedding ... eg the JAE 100 which drwas the receiver down with screws [ without adding a lug ] or the various designs which "free float" the barrel with a different op rod guide that becomes a bedding surface.
If you can outshoot a non-lugged M-14 rifle, then you already will know that almost any decent bolt action would be a better choice for target use than spending BIG bucks for a lugged M-14 or a special stock.
And I say this as someone who has a JAE stock for sale ...
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