Swing-away scope mounts

Are these mounts worth using? I bought a Rem 760 that I want to use a scope on, but be able to use the iron sights in emergency. The scope is a 40mm, will the mount allow this size objective without hitting the barrel? I'm afraid see-thru rings will put my cheek too high on the comb of the stock.

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Thanks, Grizztribefans@sssnet.com