Loose scope rail on RWS 34

[seven08]

While shooting this evening I felt some movement of the scope while turning the objective. The one piece RWS scope mount screws were tight.....now what. Off comes the scope to reveal the source of the problem. Two of the three small flat head screws attaching the mount rail had sheared off. This looseness has just happened over the last day or so. These screws are peened over on the inside of the tube and never meant to be removed. Looks like I will be contacting Umerex tomorrow for possible warranty service. This was a Dec. '17 made gun in .22 with more than 12K shots fired. 



EDIT....It just remembered this is the same gun that hit my garage floor scope first several weeks ago.. That impact bent the Vortex scope tube and the scope was replaced under their VIP warranty. I wonder if the screws could have been fractured at that event?



No worries though, I have my older spare 34 to keep me occupied for the time being. 

 

[marflow]

a bit odd but there it is I would think they would have to replace the compression tube and I hope this is cover by them

that limited lifetime warranty that come with the rifle is an unknown to what that mean to me

bad batch of screws

good luck

 

[Guest]

Seven08, I am pretty sure that your scope rail is just riveted on to the compression tube. Those screw heads are not sheared off, they are just dummies on top of the rivet head to make it look like screws. What makes me so sure is that you say the screws are peened over on the inside ... you're looking at rivets on the inside not screws that have been peened over.

I used to have an RWS model 34 original made in 1980 that have the same exact problem. To fix it properly you can drill out those rivets and replace them with larger ones and then replace the dummy screw heads that I believe are plastic.

Or you could do it the way I did.. I drilled out the rivets and removed the dovetail scope rail, and replaced it with a Picatinny scope rail. I attached the new picatinny rail with 3 flat head machine screws with a lock washer and nut inside. I use extremely skinny nuts on the screws and even then had to grind them down slightly with a dremel to allow this gun to cock correctly. When I was finished the scope rail was absolutely rock-solid from then on!

 

[seven08]

CHUCK, as evidenced by the magnet, the heads are steel. I looked at the longer head with a 10X loupe and can see the remainder of the threads, so I believe these are non hardened screws easily peened over inside to permanently keep them tight. I don't have a warm fuzzy feeling Umerex will give me the same VIP treatment that Vortex did. I will call Umerex tomorrow to see if this is a common problem. The front and rear screw broke, the middle is intact but loose allowing the rail to move. 

 

[Guest]

Unbelievably mickey mouse way to attach a scope rail...I see now that you are right and that I was not. I would definitely contact them and see what they will do about it for you. Sorry not to have been more help.

 

[ranedouglas]

...those 2 little screws held up pretty well if that's all that held your dovetail on. ive seen those little screws sheer off before, but never both of them. seems diana would make their rails like bsa or hw and have tabs that tuck the rail into place , while the screws lock it in permanent place... at least i havent had to remove a rail to get new parts into a modern (post 1984) diana....maybe that's why the screws has been flattened inside.... wonder why they dont spot weld there, too ? a heavy scope and harsh recoil would put too much stress on tiny screw holes. umarex would install scope rails onto the diana p5 magnum pistols , seemed around $120 for that , but if you decide to retap those holes a little bigger and use screws again - you might have to remove the rail to get the piston seal in and out without damage . lots of hatsan webleys were knicked and ruined piston seals upon assembly.....the screws for that dumb scope stop were installed before the new piston and seal - the screw points didnt hinder the turkish from making their quotas..... ive seen a few side lever mag dianas that had the rail spot welded or tacked back on . - paul.

 

[seven08]

I called Umerex just now for advice. I could send it in at my cost for evaluation to determine if defective parts or owner caused damage. ( my gut says the impact broke the screws) If a warranted repair they will fix it, if not I pay for repair. Then I have to pay another $30.00 for them to return ship it. The gentleman asked if I was up to repairing it myself. Yup, can do. He is sending me three new screws as a courtesy.

UPDATE:

I was able to remove the three broken screws in a few steps of careful drilling then turning out with a small tap. The thread size measures M3.5 x 0.6 and I have none of those in my shop of course. I'll just be patient and wait for the replacements to arrive. There is easy access to peen them over with a punch from the bottom.

 

[Yarddog]

You might want to consider using a high-strength epoxy between the rail and the tube when you put it back together to reduce the impact on the rivets you'll be installing. I've never done that, however, it seems that it might be a good idea. 

 

[HeyU]

I've seen a recoil dampening scope rail,( not the BullsEye ), ah,,Sportsmatch Dampa mount. Something to consider.

 

[seven08]

The rail has anti slip bosses stamped into them via the scope ring stop pin recess. They are in front and rear and go into the large holes in the tube. That along with the three screws is a solid attachment I believe. That ten pound rifle took a three foot drop landing upside down scope first on the concrete floor. It is amazing that all three screws did not snap heads off and separate rifle from scope. I have been shooting it that way for a month and 2000 shots with no noticeable accuracy problems. Glad the center screw was OK or else that new Vortex might have hit the ground, too.

 

[marflow]

I tried to take off a Diana 48 mount years ago and of course that didn't happen and always wondered how they did set the back of the screws

is it a press or what and the screws can't be to tempered and hard or they couldn't spread the back of the screw to peen ?? 

the reason I wanted to take my mount off was to see what it would take to replace it with a Weaver-Picatinny rail

so back to your mount how do the screws shear and the lug has no damage or even a mark, I go back to my first post very odd

 

[seven08]

I can't be sure how the factory mashes the end of the screws over. Some sort of pneumatic punch press affair I guess. I should have no problem duplicating that flattening with a 3/16" pin punch and hammer. Yes, the screws are not hardened beyond mashing the ends flush with the recessed inner pocket.

I also can't be 100% certain the heads weren't compromised during the fall impact. I am only 98% certain that is what broke them off. I do not think that they sheared , but were pulled upwards at impact to the point of breakage. 



I had another annoying issue I dealt with using my trusty hammer. (great tool the hammer) The front stock screw yoke loosened up some from vibration. The extra heavy factory screw stakes made it impossible to tighten or loosen the phillips screw. I could always feel stock movement when handling the forearm area. I added four deep stakes to tighten the slop in the yoke slot. Much better now. My 15 year old 34 has the same yoke and has never loosened up.

 

[seven08]

After an extended wait with no complimentary screws, I called Umerex today for an update on them. Bad news, they do not do that repair there and have no such replacement screws available. My open job ticket was just filed with no call back to me. Oh well....go to plan B. I had several 6-48 gun screws and a tap in my collection that were the right length. I merely opened up the M3.5 threads with the slightly larger 6-48 tap. The screws were too hard to peen over as is. Two minutes in the propane torch flame to a orange hot condition softened them up just right for mashing over inside the tube. I had to support the head as to not drive them through and destroy the threads. The job was a success and I put the scope back on.

 

[walter3rd]

That seems a huge pain in the butt! I hope my48 does not have that issue. All rifles should be made like weirauch. Dove tail cut into the actual receiver. Common sense 

 

[RC1947]

Nicely done! RC