Advanced Marksmanship Sterling Shooter, or other aperture sight gurus?

[NaHa]

Have a Palma rig outfitted with a Warner #2 rear and a Gehmann #566 iris. How the heck do you keep the iris from unscrewing where it's threaded to the rear sight when you change the iris adjustments?

I wanted to adjust the aperture -- the range being 0.5 to 3.0 -- and when I turned it to the left, the whole iris unit starts unscrewing from the mount. Dang it!!

What keeps these things securely fastened while still letting the user dial the aperture, and in this case, the color filter adjustment ring?

 

[9H_Cracka]

Re: Sterling Shooter, or other aperture sight gurus?

There is a lock nut that uses a special wrench that should have shipped with the rear aperture. Index the aperture assembly so its mark is at 12 o'clock then tighten the lock/jam nut.

 

[NaHa]

Re: Sterling Shooter, or other aperture sight gurus?

hmmm, sounds like I don't have that. I'll take some pics and post them tomorrow, in case you care to look them over.

Thanks for pointing me in the right direction.

 

[9H_Cracka]

Re: Sterling Shooter, or other aperture sight gurus?

this is as clear of a shot as I can find of the jam nut:

http://www.gehmann.com/pages-en/detail.php?id=169&headline=Zoom

and here is a pic of the wrench:

http://www.okweber.com/images/thumbs/ge-510_thumb.gif

 

[Alan Warner]

Re: Sterling Shooter, or other aperture sight gurus?

Nate:
I answered your question three or four days ago on the phone.
Are you still being outsmarted by inanimate objects?

Give it up, Sell the rifle, take up golf.

 

[NaHa]

Re: Sterling Shooter, or other aperture sight gurus?

Al, thanks for this last piece of advice, but golf is not for me. Once I realized that the intermediate piece -- between your #2 and the Gehmann #566 -- was really an integral part of the Gehmann unit, I regained my ability to match wits with inanimate objects.

Cheers from the left coast.

P.S. First day out with this rig, prior to monkeying with the rear sight, I had it on a benchrest (no prone shooting possible at this particular range the way they've built the firing line enclosure) at 100y. Using FGMM 155 ammo. Had a "military" 200y target with the black circle being WAY big for 100y, but it's what I had, vs. 50' smallbore five-bull targets. The aiming black must be almost a foot in diameter. I opened up the front aperture (RightSight unit with integral Gehmann 4.0-6.0) all the way, and barely got a ring of light around the big dark circle downrange.

After zeroing the rifle in three shots, I fired a group of five into 3/4", and then a group of ten into 7/8". I figure when I sling up and go prone, those groups will increase by a factor of ten, until Jerry Tierney takes pity on me like Mr. Miyagi did with the Karate Kid.

 

[9H_Cracka]

Re: Sterling Shooter, or other aperture sight gurus?

The rightsight uses a screw-in Gehmann 30mm aperture, not an "integrated aperture" you speak of.

http://www.auburnscouts.com/stallingsmachine/rightsight.htm

I'm with Al on the inanimate objects comment.

 

[NaHa]

Re: Sterling Shooter, or other aperture sight gurus?

Whatever.