Setting up KK500

[jhodge]

Hey All,

I just picked up a Walther KK500 with the Expert stock and INSIGHT-OUT rear sight. I'ts been a long time since I've shot anything with open sights, and Ive never set up a real prone rifle before. So with that in mind, when I'm in the prone position, how far away should the rear sight be from my eye?

Thanks,
Jay

[Tim S]

2in is a sensible starting place, but it might be say an inch shorter or longer. You're looking for a balance of between the gap around the foresight tunnel, foresight clarity, and brightness. A short eye relief gives a brighter sight picture, and more space around the foresight, but the foresight might be less clear. A longer eye relief has the opposite effect: darker sight picture, and less space, but a sharper foresight. In terms of space around the foresight, the textbook answer seems to be a gap equal to the tunnel, i.e. the tunnel takes up the middle third of the rear aperture.

One way to set eye relief is to remove the rearsight and mount the rifle (after adjusting the handstop and butt length to suit you) Have a helper fit the rearsight onto the front of the receiver, and slide it back until the proportions look right. Having the rearsight in situ when you shoulder the rifle can cause you to cramp or strain your neck, giving false positives

If your rearsight has an iris eyepiece you can use this to control brightness independently of eye relief. 1.1 or 1.2mm is normal as a start. Don't crank the aperture right down to sharpen the foresight, this usually makes the sight picture too dark and strains your eye. A prescription lens (distance +0.5 typically) is a much better solution.

[jhodge]

Thanks Tim, appreciate it!

Jay

[F/V Icy Swan]

". . .In terms of space around the foresight, the textbook answer seems to be a gap equal to the tunnel, i.e. the tunnel takes up the middle third of the rear aperture. . ."

Tim S, how do you adjust this gap? I just picked u8p a FWB 700 with stock sights. It is not grossly obvious to me how this particular adjustment works.

Thanks for your insights. I hope everything is tickety boo there.

Mike

[40xguy]

This is an EXCELLENT article on setting up a rifle, hope it helps....

viewtopic.php?f=3&t=58327

[F/V Icy Swan]

40Xguy, thanks. that is perfect.

Happy new year to all.

Mike

[Tim S]

". . .In terms of space around the foresight, the textbook answer seems to be a gap equal to the tunnel, i.e. the tunnel takes up the middle third of the rear aperture. . ."

Tim S, how do you adjust this gap? I just picked u8p a FWB 700 with stock sights. It is not grossly obvious to me how this particular adjustment works.

Thanks for your insights. I hope everything is tickety boo there.

Mike

Mike,

It's quite simple: you move the rearsight to alter the perceived size of the aperture, and it's size relative to the foresight*. Move the rearsight closer to your eye to make it (and the gap around the foresight) larger. Move the rearsight away from your eye, towards the muzzle, to make the aperture smaller.

The rearsight will be held onto the dovetail with a screw. Loosen this 1/4 or 1/2 turn to move the sight.

*Depending on the length of the dovetail the foresight rises on, you could fine tune by shifting this too.

[F/V Icy Swan]

Tim S,

I have been overwhelmed by the almost infinite adjustments and was happy just getting the cheek piece height set so I could see both the rear and front sights. Now I know how to work on getting the relationship of that gap. I am an older shooter just learning 10M standing air rifle on my own. It is something I can do indoors in the Arctic. I have not tried prone or other positions, but this is a start. Thank you for sharing.

I will work on getting the gap proper and correct.

Mike

[jhodge]

Wow, thanks for all the great replies. I'll work on all this stuff today, and try to report back.

Jay

[jhodge]

Took the KK500 out to the backyard and shot some targets. Wow, I'd forgotten how hard open sights are! Anyway I think I might have too much hand stop pressure, and not enough butt plate pressure, so I need to do some more noodling around with the stock.

Jay

[Tim S]

Jay,
A promising start, clicking up and left would have helped a couple. What were the conditions like?

If the butt is loose, and your hand is taking the recoil, usually there are three common responses:

Move the handstop forwards (sliding the whole rifle back)
Extend the butt
Shorten the sling.

Moving the butt or handstop will keep the rifle/position at the same height from the ground as now. Shortening the sling will lift the rifle. You may need to mix 'n' match from all three, until the height of your shoulders and the rifle is comfortable, the buttplate is snug, and your hand falls onto the grip easily.

This might be obvious, but the rifle can also fall away from the shoulder when it's very muzzle heavy. Now, assuming you haven't added either weights or an enormous bloop tube, in my experience a rifle is most often nose heavy when the supporting (left?) hand is behind the point of balance. This can be an issue for juniors and petite women (more so with wooden-stocked rifles), but also with adult men when the buttplate is extended too much; IMO it's not necessary that the butt is equal in length to your forearm, or so long your arm and hand are flat against the stock. When the butt much too long, this limits how far the support hand can reach, and may push the weight of the barrel too far in front of the support hand.

[jhodge]

Hey Tim,

Thanks for the input.

As far as conditions go, dead calm, mid 30's for temp, and very flat (completely overcast today in Cincinnati) lighting.

I have not added a thing to the rifle. No weights or bloop tubes. I used the information from the links in this thread to get a basic starting point and started shooting. I like my rear sight placement (it's about an 1 1/2 from my eye) as it seems to be a fair compromise between front ring sharpness and overall brightness.

I'm going to move the hand stop forward an inch and try again. Probably best to change one thing at a time at this stage!

Jay

[Tim S]

Jay,

An inch is quite a bit to shift back the rifle without lengthening the sling too; if the butt was an inch off your shoulder, you'd have noticed before your first shot. That inch will push back your shoulder, so you rotate your body to keep the spine straight, which changes the orientation of your head to the stock/sights, your body to the butt hook (if used), and raises you a bit. This may be beneficial, but it is actually quite a big change to make in one go.

Personally I think a tight sling/position is good, but I also think there is a fine line between tight and too tight, and tension should be increased gradually to acclimatise and evaluate.

[jhodge]

I ended up moving the hand stop forward about 1/2", and the rifle did have a more secure feeling in my shoulder. I think my main problem here is simply my vision and open sights. I had a lot of shots that were off call. Seems to me that the front ring that came with my rifle is a little too big. It's hard to tell if the bull is centered because its just swimming around in a sea of white. Anyone here use the adjustable front iris? Or what size fixed seems to be the best?

Jay

[Tim S]

Jay,

I'm afraid there is no best size that works for everyone. Most shooters use fairly similar sizes, but not exactly the same. The normal range for Prone would be 3.6mm to 4.2mm, that's for a 30-33in sight radius on the ISSF target (maybe 0.1-0.2mm smaller for US NRA targets). A longer sight radius needs a proportionally larger aperture, and vice versa for a shorter radius.

As a rough rule, you want an aperture that's large enough to contain any wobble in your aim. Newer shooters often like a small aperture, because they can't see so much wobble. But this means small apertures aren't as reliable, unless your hold is absolutely rock solid, and most newer shooters are not steady enough. The inner edge of the aperture looks sharp, but it isn't. It's actually fuzzy, and there is a halo of dirty (diffracted) light around the edge. When the aperture is very tight around the target it's possible to overlap the target without noticing, because the blurred edge looks the same as a very thin gap. An aperture in the normal range leaves a broader gap, so it's hard to overlap the target. The broader gap is also brighter, and this helps to centre the target, as we can see the difference in brightness better than movement.

As for variable iris foresights, these are useful if you want an odd aperture size, like 4.07mm, or want to compensate for ambient light by tweaking the aperture (brighter light makes the backing paper look brighter, so the target appears smaller). I use an aperture because I can have a really thick ring to balance a large aperture. The downside is that irises can break. There's a lot to be said for the glass Centra inserts: simple, reliable, and sold in lots of sizes.

[jhodge]

Tim,

Pulled out the aperture that came with my rifle, and it's a 3.8. Thats right in the range you talked about. I went ahead and ordered both a variable front and rear iris. That's one way to find out what my eye likes!

Jay

[mhampel]

Your front apperature should be "as big as you can stand". Bob Wright, a legendary Ohio long range shooter told me. Another shooter I met at the Smallbore National Matches (I wish I could remember his name, a friend of Wigger) told me when he encountered a competitor who professed the need to run a tight apperature would offer a challenge to take his front apperature out and beat him.
For NRA smallbore targets, I have mine open to the edge of the paper. Long range, I do the same thing. I have lots of problems, but vision and centering the bull are not among them. If light bleeds in around the target, I get into problems.

The link below has an article explaining why an open apperature is desirable. Unfortunatley, you have to download the whole magazine. The article starts on page six.

www.usashooting.org/library/USAS_News/j ... 11ver5.pdf

[jhodge]

Hey All,

Shot another match yesterday, and while still placing last, wasn't more than a few points behind a couple of pretty good shooters. After the match, I let another guy shoot my rifle, and I spotted through his spotting scope. It's a Celestron (not sure the exact model) with an astronomical eyepiece. Wow, what a difference from my cheap Chinese piece of crap. I am now on the hunt for a nice spotter. In the 800.00-1100.00 range I seem to have it down to the Celestron Regal M2 and Kowa 82SV. I believe that I might need to buy an appropriate eyepiece for whichever one I decide on. Anybody out there have experience with either or both? Other brand or models to look into?

Thanks,
Jay

[DavZee]

I had two Celestrons and both broke on the focus mechanism. I’ve been using a Konus for years now and have even had my stand fall over with it at the top a few times. It still works fine.