Scope objective lens size?

[Ought Six]

There's an interesting article on the SniperCountry.com site that says that large objective lenses on tactical or hunting scope are useless. The author claims that with a good quality scope, you get all the light transmission you need out of a 42mm objective, even in low light conditions. Further, he says a 50mm or larger objective means the scope must be mounted higher, preventing a proper cheek weld with the stock unless you have a target-style raised cheekpiece.
Let's say you're setting up a tactical bolt-action rifle in the .308/.30-06 class.

- Do you buy his argument about the larger objective lens (say 50mm, as opposed to 42mm) giving you no substantial benefits?

- If you think the larger objective is worth it, do you agree the larger objective significantly raises the sightline, preventing proper cheek weld with a standard stock?

- If the answer to the last question is 'yes', do you feel comfortable with the raised cheekpiece stock solution?

- If a larger objective lens means a heavier, bulkier, more costly scope, and a bulkier raised cheekpiece stock, is all of that worth it to you for the advantages such a scope offers to the tactical rifle package?

 

[Nukem]

Yes, no, maybe I've got a Leupold LRT 6.5X20X50mm side focus on a McMillan A4 Tactical stock. It has a very nice adjustable cheek piece. The 50mm is OK on it.

It's not OK on my flattop AR, too high. I don't want one on a hunting rifle either.

Trade offs.

 

[DAVID NANCARROW]

I have used a Simmons 6.5x20x50 on my Remington 700 VS in 308 for 5 hunting seasons now, and I find that I do see just a bit better than the 40mm I'd had on there before at dawn and dusk. I used medium rings and while it gives me mirage after 4 magazine loads full at the range, I haven't seen-let alone tried to shoot a deer at my range. The VS has a pretty standard shape to the stock, but I don't have a problem with the scope size albeit the rifle is 9lbs clean. I do think its interesting the military sniper scopes are 50mm objectives. I think its a toss up as to whether I would put a 50mm on a lightweight hunting rifle. I just bought a used M700 in 270 Winchester with a 3x10x44mm Simmons on it, and it feels okay, took deer with both rifles last week without incident. I don't think I'll change the scope on the 270-its good enough.

 

[Matrix]

Most of the guys at "Sniper Country" know their stuff.

I have a Leupold 3x9x50 on my 7mm mag., which is my primary hunting rifle. It's been a good scope, but it is high above the sightline. If I had to do it over, I'd get a 40mm objective. You get a better, more consistant spot weld with the 40mm, allowing you to shoot more accurately. Scopes should be as low and as tight as possible.

There is a formula that allows you to measure the light tranmission, which is affected by the power and the objective size. Simply put, if it is too dark at 10X, go to a lower power.
The quality of the lenses and lens coatings are very important in how the light is transferred.


Also, most military and police snipers use the 40mm objective.

 

[Herodotus]

As far as the stock problem goes:
The stock on a rifle can only alaign you eye to one height. You can get types that adjust, but they are a pain in a lot of respects as well.
Most factory stocks today are indeed made with the intention of putting on a scope sight, but, of course, the scope envisioned is some mythical average one. The stock is also made for some mythical average person.
If your unique body deviates too much from this norm, you won't be able to get a good and natural sight picture no matter what sight you put on the rifle.
You cannot expect that a factory (or even better) stock will work well with some very large objective, high riding scope.
Going in the other direction, its impossible to make a little scope work with iron sights though you can come pretty close.
If you are going to get a huge scope or want to have a rifle that is near perfect with iron sights, you had better figure on having a custom stock made to your own unique measure. To do this, you have to decide upon what sights you really want on your rifle before the stock is made and then stick with it. A custom stocker could easily make a stock that would work great with a big scope, but he would have to know before hand what you were going to use (mounts included) and what your physical characteristics are.
I value this character of the rifle coming up to my eye naturally very highly. I do not want rifles that do not do this for me. So I would not want to invest good money in any project that would not produce this result. I am lucky in that a good number of rifles out there will do this for me without getting into special work.
The guy who says you cannot get good cheek weld with a big scope is wrong, unless he is just saying most rifles are not made for them, which is no doubt true.


[Edited by Herodotus on 12-07-2000 at 08:30 AM]