You must not have tried. An aperture with a big hole mounted traditionally on the rear of the receiver blurs and is essentially out of view while you fired the rifle. They are faster and much more accurate than the open rear sight and bead supplied by companies like Remington. An aperture mounted in front of the receiver on rifles like the Japanese Arisaka bolt action works the same way. Many moons ago I owned a 7.7 mm Arisaka. That rifle changed from owner to owner at the local range being sold for $30 each time. A Herter's FL die set was always included with it. All 4 or 5 of us got it to group jacketed bullets into 1 1/4" at 100 yards. Arisakas actually have a lot of strong points but being attractive sporters is not one of them and we all had nicer bolt actions. Also using the peep sights in the barrel mounted ladder sights on .45-70 Trap Doors, .30-40 Krags and 1903 Springfields is the most accurate way to fire them if you have time and good vision to focus through the tiny holes. While they are not as good as apertures mounted on the rear of the receiver, for hunting deer I'd rather use the new Rossi's barrel mounted peep than the factory open sights most lever actions come with.