Since a 30mm scope tube is a 30mm scope tube, the only difference has to be towards the interior. If the scope has a thicker scope tube wall, it means smaller lenses which can affect its ability to transmit light and/or limit elevation/windage adjustment.
I really don't think anyone wants to saw some big dollar scopes up to see what is inside.
The internal mechanicals could have more metals instead of plastic but that is shared by both brands. That dirt cheap Elite 3200 is OEM on Barrett 50's. Says alot about how they are constructed. Now why can't they make some 4200's with that type of simplicity? fixed 16, 20 or 24X with 75 to 100mins of adjustment - yeah, that would sell.
I don't believe in hammering scopes or dropping them onto concrete floors to test their durability. But I have bounced a few Elites while hunting with no issue or loss of zero.
What does that prove? Nothing really. Both NF and Elites are made to very high standards and both do work very well. I bet their alloy tubes are made from the same stuff and their finish is the same too. For lenses and coatings, I really don't think there is much difference here either as the Japanese pretty much have that all figured out.
Many consider the Rainguard one of the industries best coatings. it certainly meets the highest levels of single surface light transmission (was from a optics report so you can take that info anyway you want).
Lense resolution at high mag is the one big compromise that Bushnell sometimes makes. But NF also looses some at full mag too. In fact, the NXS I was comparing got down right distorted at the lowest mag...strange. Sightron SIII is the only of late that doesn't.
I fully concede that NF is one of the most progressive optics companies and is doing a superb job of making niche market products for the widest range of users. This is the only company that feels ALL shooters are their potential customer and make products to suit. Leupold is very similar but not with the same performance vs $$$.
Most of the Japanese companies just think hunters are their one and only audience and give little thought to the match or tactical shooter (no big fat knobs and a mil dot reticle isn't all that we want). Pity, as this is what has propelled NF to great heights.
But companies like Bushnell and Nikon are offering such great products for a fraction of the price. That is huge with consumers.
Each year, Nikon and Bushnell ease gently towards more diverse product lines despite the emails and suggestions from shooters like me.
Sightron seems to be taking heed and with their success on their SIII lineup, maybe, just maybe, they will be the next to support such radical engineering tricks as etched glass reticles and FFP and a couple of big fat knobs
Jerry