11mm rail on the theobens

[etiam viviens]

I have 3 theobens and I have two 11mm rails on two of them.
I mounted several scopes rings on them with out any problem BKL, sport match etc.

Until I needed an 11mm to picatinny riser on one of my Raw´s and the riser did not fit.
That one was engineered for steyr rifles and the are very scharp machined and that is a problem with other 11mm rials I am told.
But i did not expect that it would not fit on all of my pcp's and it only fits on the AA TX200 and HW97.

I did measure the rails of the Raw/THeobens and one is on its widest 12mm, one of the theoben rails is 13mm.
So I have 1 Theoben with 12 mm, 1 theoben with 13 mm and a Raw with a 12 mm rail, none of these will except the 11mm to picatinny rail riser.

So I was wondering what is the standard 11mm rail that was made for the Theoben rapid or Raw air rifles.
And why do I have two different rails dimensions and is this normal of theoben or are they aftermarket rails.

I am planning to order two Daystare monorails for the alpha wolf but it I have strange "11mm" rails I could better wait I think.
Think I missing something and hope some one can enlighten me.

[angrybear]

If I understood correctly the first thing is it depends who made the rail, some machine the dovetail to a sharp edge, others round that edge, it is actually the inside/undercut of the >< recess that matters, not the outside edge.
 
I remember there was a long thread on the old R7OC forum on this subject & there is no agreed size/angle of dovetail unlike weaver/picatinny that has set dimensions.

Look carefully at the riser as you try to fit it, it may be the bottom sharp edge of the riser (that will be inside the rail undercut) that needs rubbing down rather than the outside edge of the rail.
Sometimes just filing a lead in angle on the corners will allow you to tap the riser on with a soft hammer.

[etiam viviens]

That was something I was thinging about, just to file of the bottom edge of the rail on both sides.
But was a bit weary to file down a riser of 120 euro´s

When I google the dimensions of the a 11mm rail, all the drawings show a with off 11mm and not the 12 mm or the 13 mm that I have on my rapids or Raw. I was wondering if this is the standard of the 11 mm rail or do I have the luck to have 3 special rifles?

[angrybear]

No, As I said there is no defined dovetail size, they come in size from 3/8" to 11mm(ish) to 13mm on BSA to 15mm on I think CZ (?)
so not all rails/rings will match up,
and the more expensive higher quality parts will have tighter tolerances to fit a rifle with an equally tight matching tolerance 

Had you bought a cheap generic riser it would probably fit them all without issue 

[etiam viviens]

Thad indeed looks like it is the case, will see if I can modify the rail and if the rail of the Daystate Alpha Wolf  wil fit the Raw and Theoben rail.

[Squinty]

do you mean that you have two DTR adddons that fit '11mm' risers but the integral dovetail on your early? RAW isn't 11mm?

Or the addons are different widths too?

[etiam viviens]

do you mean that you have two DTR adddons that fit '11mm' risers but the integral dovetail on your early? RAW isn't 11mm?

Or the addons are different widths too?

My early raw from 2013 or so (has threaded fixation holes for the trigger cassette that where removed from the later Raw's) has 12mm rail
One of my theoben has a 12mm rail the other has a 13mm Rail.
I have bought these second hand and I do not know if they are original or aftermarket.

Did ask a guy on the airgun nation if he could measure his Raw TM1000 rail and it was also 12mm.
He was using a mono rail from the daystate Alpha wolf, that looks like a good fit.
So I have ordered a mono rail from Daystate and hope it will fit my Raw HM1000x
Pictures from the internet

[Squinty]

ah, if i remember correctly the TMs and Impacts had machined dovetail rails, Theobens just had the raised rib and 2BA holes.
But I was told by Mr Tawn of Tawnado that nothing was wasted so even if a blank was too wide the rib was machined the same distance in from the outer edges and a mount was bodged to fit

He realated a story to me about one such Rapid and a customer who had purchased some set back mounts that wouldn't fit and it turned out that the block was indeed wider.
Can imagine that it was a joyless exchange as Mr T would go into complaints with shields raised and phasers locked on.