Re: 1" tube or 30MM
When looking at scope tube diameter, you can't mess with "fact" and opinions are invalidated by the "fact" that the human eye has a maximum exit pupil or light gathering ability, to 7mm only.
As long as the scope has the ability to create a 7mm exit pupil and nearly all 1 inch tubes will do that,then the real reason for selecting a 30mm tube can only be justified for other reasons.
The most common reason is because you want one, or you like the look of a particular scope designed with one.
The second reason is one of logistics, meaning the mechanical benefit of allowing scope rings to grip on the larger surface area of a 30mm tube for heavy recoiling rifles.
I have one scope only with 30mm tube and because I am a gun writer, it was given to me as an R&D exercise because I had a reputation at that time, for breaking scopes on my heavier rifles. This was a Tasco Titan 1.5-6 variable which I mounted on my .460 Weatherby in 1996 to determine how long it would last until I broke it.
The rifle has fired over 500 rounds since then with the heaviest recoiling loads ever shot from a .460 up to 600 grain weight at a chronogrpahed 2450 fps. This is serious 8000 FPE and 100 Ft Lb recoil levels.
The rifle has been around the world twice since then and has never changed zero. I so far, have not been able to break it.
Because Tasco is sold in "el cheapo" retail stores in the U.S. it does not command the same respect from the hunting fraternity as does the higher priced scopes with more traditional names.
What the average consumer does not know is that Tasco scopes are made in 3 countries. Their cheaper scopes are made in Taiwan or China and they better scopes are made in Japan with some such as the "World Class Plus" in lieu of the plain and cheaper "World Class" have turrets and lens' the same quality as the Leupold Vari 111.
I found this out during a writers seminar when I met an ex Leupold distributor who changed camps and went to Tasco and he knew the mechanical details of the scope intimately.
I am not defending Tasco or suggesting that they are top quality scopes, just highlighting that some of their products are as good as any, and cheaper if you know what to look for.
They still make what I call "disposable scopes" as does anyone who sells something that fails to do the job I intend for it. I am very hard on equipment and after killing around 5,000 animals testing rifles over 42 years, I hate cheap crap as much as anyone.
Something to ponder.