Hi Guys,
Here is a SUPER CHEAP little trick to save the screw on the top backside of Diana scope rails as well as your scope mount system.
For those who don't know, that screw/screw hole is meant to attach some types of Diopter sights to the rail. Diopter sights are very popular in Europe; most Americans tend to favor scopes or just keep the factory iron sighting system. If you don't know what a Diopter sight is, here is an example.
Ok...back to business...
The scope-stop hole in the Diana scope rail is generally not large and deep enough to properly accept the "stop pins" on most ring sets and 1 piece mounts; many people are not comfortable drilling the hole. It is generally, and wisely, recommended that people NOT use this screw as a scope stop as they can shear off and be a real pain to extract, especially if they shear off flush with the top of the rail, but there are times when it seems as if there is no choice...here is a little trick that ANYBODY can do to save that screw and your mounts, costs .20 cents or less, and is available at almost any local hardware store or Home Depot!
One problem that some people have with the Diana Magnum guns is that IF they remove this screw, the scope mount will "walk backwards" as the gun is fired repeatedly. So IF you can't afford the $20 or more(+ S&H) to purchase an aftermarket, store-bought scope stop, what can ya do?!?!? Well....
Here is that .20 cent trick that will
G-R-E-A-L-T-Y reduce the possibility of the screw shearing off when the scope mount is butted up against it and it WILL stop the gouging of your mounting system!
Let's look at a couple of pictures to see what is going on.
In the picture below you see a Leaper's 1 piece scope mount with 3 clamping screws - the mount is cast aluminum, poorly cast & finished I might add, it's painted/coated black - you can also see that there is a gouge in the base of the mount that is showing which is silver - that is where, over time, the SHARP bi-directional recoil was forcing the mount back into the screw and gouging into the metal. This gouging occurs due to the SHARP, acute vibrations causing the softer metal of the scope mount to rub/vibrate while pressing back into the much harder metal screw - metal on metal ya know - it is very much like an impact hammer beating away on both the scope mount AND the screw; the gouge that you see is deeper than what it appears in the picture.
Below you see another picture with the scope mount attached to the rail. You can clearly see the screw which gouged the scope rail. You can ALSO see that there is now a little .20 cent rubber O-Ring that fits perfectly over the screw. I have cut part of the side of the o-ring away so that you can see with better clarity what is going on and the screw that I have been talking about.
The .20 cent o-ring acts like a
SHOCK ABSORBER thus preventing not only the gouging, but it dampens the sharp vibrations that could ultimately cause the screw to shear off.
Here is a procedure that you might wish to follow for attaching scope mounts to the rail.
- After the bottom clamping edges of the scope mounting system and the dovetail rail on the gun have been degreased with rubbing alcohol and Q-Tips to help in preventing slippage, the little o-ring is slipped over the screw on the top of the rail. Now, hopefully the mount has a stop pin...if you do not want to remove the scope from the mount but the stop pin is not lowered enough to engage the hole in the rail, what I do is to put a drop of Crazy Glue on the FLAT end of a wood dowel and slide it up into the stop pin hole in the bottom of the mount an press it against the stop pin itself. When the glue dries, you can GENTLY twist the dowel to lower the stop pin as needed. I advise that you twist the pin out a bit further than necessary and apply LOCTITE 242 (blue) to the threads on the pin and then screw it back up into the hole leaving the proper length exposed to fit into the stop hole in the rail.
- If you are willing to remove the scope from the mount, follow the aforementioned degreasing procedure, then place the mount on the rail and VERY LIGHTLY tighten the clamping screws with you fingers - WITH YOUR FINGERS - so that you can gently slide the mount back against the screw that has the rubber o-ring on it. Push the mount against the o-ring hard enough to compress/pinch the o-ring and THEN tighten the clamp screws as tight as you can with your fingers WHILE holding the mount TIGHTLY back against the o-ring/screw. NOW gently tighten the clamping screws with a wrench/screw driver/hex key/etc. Remember, don't strip those screws and tighten them evenly - I tighten the screws starting in the middle and working out to the back and then out to the front....just my "personal" method.
Now the mount SHOULD be pressing against the o-ring hard enough to compress/pinch it.
- Now screw the scope stop pin down to the rail with enough force as you think is required - don't strip the threads on the mount or the screw...just tighten it up good and tight...I like to put LOCTITE (blue # 242) on the scope pin before setting it and tightening it up.
What WILL happen after some shooting is that the o-ring will split, but will stay attached to the screw as it is pinched in between the mount and the screw. So what I suggest is that you take a new and SHARP razor blade and cut the o-ring as you see in the picture below.
O-rings are CHEAP, and I buy a couple of bucks worth at a time and keep them in a pellet tin along with some other goodies that I keep in my shooting box.
Well, that is about it. I hope this helps solves problems for those of you who do not have a store-bought scope stop.
I have done this many times for people who jut don't want to get a store-bought scope stop, and when I work on a Diana that has a scope on it and is lacking a stop, I add this for the benefit of the client/friend....it is CHEAP, easy, and best of all it is HIGHLY EFFECTIVE!
I put an o-ring on my buddy's Diana 350 Magnum 2 years ago and he has had ZERO problems and no more gouging!! He shoots about a tin of 200 .22 cal Crow Magnum pellets every week....
I personally use a BKL 260D7 scope mount as they have 6 screws yielding TREMENDOUS clamping power AND they have compensation for barrel droop factored into them...they are about $60, but they are SOOOOOOOOOoooooooo worth it...just pass on 15 Starbucks coffees and you have one!!!
You can take a look at them here:
http://www.straightshooters.com/bkl/bkl260d71pcmedfixed6screw.html
Ok guys, it’s coffee/smoke time – gonna go see if I can bag a few Pigeons!
-Curtis
Poof gone