Bob,
You're right about the unseen differences. Like many gunsmiths, Mel Forbes started out (over 30 years ago) making light rifles on Remington 700 actions. Eventually two things happened: he grew weary of fixing dimensional problems with 700's, and he pin-pointed action weight as the biggest problem in making light bolt-action sporters. So he started making his own actions, and making them as dimensionally perfect as humanly possible.
When he started making actions and synthetic stocks, he recruited to help of friends who were actual rocket scientists at the nearby Hercules facility. His stocks were so far ahead of the curve in 1985 that as far as I know nobody else has ever quite caught up in syn-stock construction. So are the actions.
I believe he also had rocket-engineering help when he designed the lightweight NULA scope mounts. Talley now makes these, both for NULAs and for other rifles, the Talley Lightweights that have become so popular in recent years.
Partly as a result of the stock, after considerable experimentation he found that the best accuracy in his rifles resulted from full-length barrel bedding. Because his stocks are so well-made, I have never seen a NULA's accuracy go wonky after a few years, as I've seen in some other syn-stocked rifles.
In fact, my wife's first NULA was a .270 Winchester Model 24 with a #1 Douglas barrel. It shot a bunch of loads extremely well, even though it weighed 6 pounds on the nose with a 2-7x scope. After trying a few loads, we settled on the 130 Nosler Partition and 56 grains of IMR4350. This always shot under 2" at 300 yards on a calm day--which also shows what Partitions do in good rifles.
Every year Eileen would go to the range a week or so before hunting season and shoot one shot with that load. It always landed 2" high and dead center, the way she sighted in the rifle in 1991.
The same thing happened every year for over a decade, even though the rifle got hunted hard and went on several airplane trips around North America. It never shifted point of impact at all--until the scope eventually went belly-up. Even then POI didn't really change, the groups just got larger. When the scope was replaced the rifle went right back to shooting 1/2" groups.
The full-length bedding also does tend to make different loads shoot to the same place, even with very light barrels. The first NULA I had was a .300 Winchester Magnum. I worked up loads with various bullets between 165 and 200 grains, and noticed that all seemed to shoot pretty much to the same place
at 100 yards. Eventually I fired three shots of three different loads using the 165 Hornady Spire Point, 180 Speer Grand Slam and 200-grain Nosler Partition at the same 100-yard target, and the nine shots made a 1" group. Even most custom rifles won't shoot a 9-shot, 1" group with the SAME load, let alone three different loads.
