Recoil Pin Tolerances

[Newmatic]

Why are the recoil pin depressions on my RWS so much larger than the diameter of the recoil pins on the RWS scope mount?  Are there any one-piece scope mounts that have pins exactly fitting the depressions in an RWS?

[Roadworthy]

Year and model of RWS might be helpful.  Not all depressions are for recoil pins and I don't know which RWS models have depressions for recoil pins.

[condor22]

 To my unscientific methods I have determined that the stop pin hole in my RWS34P 11mm rail is .200 thousandths or 5mm+ 1/10 of a mm or 5.1mm?.  Results determined by fitting a screw into the pinhole and then  measuring thread OD. Not sure how to read the mm 10 line vernier, but the 25 line inch vernier is dead on 200 thousandths.

 Here we go a photo of the RWS 350 11mm dovetail rail, this is exactly the rail on my RWS34P. The holes without the screws/rivets are the stop pin holes, the pin hole on the right shows some damage.  Third circle from the left or second circle right. I have used the method suggested in this article, slide the mount forward and let the stop pin rest against the front of the dovetail rail. Not pretty, but it works, UTG made a canted rail adapter that hung over the front of the dovetail also.

 https://www.pyramydair.com/blog/2006/02/diana-rws-350-magnum/  scroll down for picture.

 The UTG dovetail to weaver adapter, doesn't need a stop pin    I didn't like this mount, it worked 100%, but......the scope was so high, I had to place my chin on the stock for a cheek weld, or a chin weld.

[Scotchmo]

It's not just the tolerance on the hole and pin diameters. The pin location (side-to-side) must be factored into the tolerance stack.

If we could be assured that the pin was perfectly centered (but it's not) over the hole, then we could use a close fitting pin. We need considerable slop in order to accommodate the mount variations.

I was going to machine a tight fitting pin at one point but decided not to after considering the ramifications.

[condor22]

It's not just the tolerance on the hole and pin diameters. The pin location (side-to-side) must be factored into the tolerance stack.

If we could be assured that the pin was perfectly centered (but it's not) over the hole, then we could use a close fitting pin. We need considerable slop in order to accommodate the mount variations.

I was going to machine a tight fitting pin at one point but decided not to after considering the ramifications.

 IF you have any SLOP, the stop pin will hammer the pin hole and damage it beyond any use what so ever! If the pin hole is off center the rings are defective or wrong size rings such as trying to mount 3/8inch rings onto a 11mm rails.

[snuffer]

Scott is right. If you make a pin to fit the hole it will not work . Every rail is made different for width. that is the reason for the larger hole. It will bind and tip the scope or not get tight.
Chuck

[Newmatic]

54 Air King .22 cal. new this year.  Same design shown in condor's pics. 

[condor22]

Scott is right. If you make a pin to fit the hole it will not work . Every rail is made different for width. that is the reason for the larger hole. It will bind and tip the scope or not get tight.
Chuck

 Can you explain, I don't understand how a correctly fit pin causes a problem, If you use the wrong rail, the RWS is a true 11mm dovetail rail, if you use a compatible, yes, the whole rail is off center and a slop fit pin will then only work with the off center rail.

Make a pin to fit the RWS stop pin hole and it will fit correctly into the RWS stop pin hole, my scope rings were straight and still are? If you you try to fit the RWS pin into another brand, who knows, most likely the rings will tilt.

If you install the pin incorrectly as in extending the pin to far, than yes, it will force the rings to tilt side ways.




 Use any rail or pin, if it don't fit, it will damage your rail, I'm desperately trying to help you prevent damaging yo Rifle. 

[condor22]

 After reading the replies to B B PelletER I have two suggestions.  Drill a new stop pin hole to correctly fit the exact size of your stop pin. As he stated 'Do not drill through the compression tube'

 Have professional Machinist make a metal insert to fit into your RWS Rifle's stop pin hole, have a hole drilled into the center of the insert that correctly fits your exact stop pin. Or a sleeve adapter that fits onto the stop pin adapting it to fit your RWS rail stop pin hole.

[snuffer]

Condor is right also. You must make sure the scope rings are right. Some rings say for 11.5mm to 9.5mm dovetails some say 9.5mm to 13mm some say 3/8 every different width changes the location of the pin hole in relation to the center line of the dovetail. 11.5 to 9.5 is .079 in. Difference. Ring makers want their rings to fit the most rails they possibly can so they make the pin smaller so they can work. If there was a way to check the location of the tapped hole in the ring to where the dovetail locates it would be great.
 I have a RWS 34 the way I made my leapers rings work was to buy 2 sets and use both pins in both holes.
I love my RWS but they could easily fix all the problems by making the rail 1/8 in. Thicker and the holes deaper or standardized all dovetails.
Condor is right to make the pin as large as it can be and still fit to the bottom of the rail hole.  Please mark your rings and if it moves at all don't keep shooting or you will wreak your rail.

[condor22]

https://www.pyramydair.com/product/utg-scope-mount-base-fits-rws-diana-48-52-54-460-magnum-with-to5?a=2297

 iF your  RWS 350 has the short 11mm dovetail rail, this dovetail to weaver rail adapter should work, it worked for me, just need a higher comb on the stock. If your 350 has the newer longer 11mm dovetail rail it won't?     I have a 34, not a 350. 


BTW I used the vintage type Weaver Top mount 30mm rings, replaceing the button top slotted screws with modern socket head screws:  These are the lowest profile 30mm rings available, bar none? 

http://swfa.com/Weaver-Detachable-Top-Mount-30mm-Rings-P10408.aspx