Question: 753 sights

[haertig]

Does anyone besides me find that the aperture of the 753 rear sight is too small to properly frame the front globe sight?  It is fine in prone, but in every other shooting position I have to force my head too far forward for comfort to be able to get the desired equal width black ring, white ring, black ring, white ring sight picture that you want.  I do have the 753 rear sight mounted as far back on the receiver as possible.

I am thinking of drilling out the aperture hole slightly so that I can have my head in a more comfortable position for the majority of my shooting, since prone is my least used shooting position (being old and fat and not very flexible tends to do that to you!)  What do you guys think?  Drill it out slightly, or leave it alone?

[Oldgringo]

I shot more than a few this afternoon off a bench and it works just fine for me.  Since my cataract surgery, I now shoot without corrective lenses; i.e., nekid eyeballs. 

If I was to get in a prone position, I'd probably have to stay in that position until help arrived.   

[ac12]

The rear sight should be adjusted forward/backwards on the receiver, to give you the proper sight picture.
If however, your head is further back than the sight can be adjusted rearwards for, then it is time to change the rear iris to a larger one, or drill it out.  The problem with drilling it out is, can you drill it out and keep the hole a nice round circle, vs. elongating it.

[haertig]

If it were possible to get the plate out of the sight and then use my drill press, no problem in keeping the hole perfectly round.  But I doubt the plate comes out for drilling.  But you're right, drilling it while still in the sight might be problematic to keep it circular, not to mention there would be small metal fragments left from the drilling process rattling around inside the sight.  Even only a very slight enlargement would still leave drilling fragments.  I guess I'm stuck with this one.  Too bad the aperture is not interchangeable, as it is on all my tang sights on my powder burner rifles (I like tang sights - ever lever action rifle gets them!)

[haertig]

In case anybody is interested, here are the initial findings of my research into the 753 rear sight modification I'm considering:

The 853 sights have a 0.050" aperture.  The 753 sights have a 0.030" aperture.  The larger 0.050" hole is what I need for comfortable head position to get the appropriate sight picture.  While both the 753 and 853 sights have screw-in apertures, the thread patterns are of quite different sizes, so they are not interchangeable.  (I initially thought the 753 aperture hole was drilled into an internal plate, but in fact it is a screw-in aperture disk, just very difficult to unscrew!)  The 753 thread patten is 9x1 metric as best I can research.  Which is not quite what European apertures use as their standard, which is 9.5x1 metric.  The 753 threads are probably re-tappable to 9.5x1, IF you could ever find a 9.5x1 tap here in the US, which you probably won't.  However, 3/8x24 is very close to 9.5x1, is a standard SAE size tap, easy to find in the US, and MAY be usable for European 9.5x1 aperture disks.  I've seen reports that Anschutz 9.5x1 apertures screw in just fine in a 3/8x24 die, but I have not confirmed this personally (since I don't any Anschutz apertures nor do I have a 3/8x24 die!)

There may be some hope though.  Midway sells a Merit adapter that allows the Merit #3 adjustable aperture to work in 9.5x1 European sights.  It costs $5.99 ( http://www.midwayusa.com/product/260353/merit-metric-adapter-reduces-m95x1-threads ).  It APPEARS that this Merit #3 adjustable aperture has the same thread pattern as the much cheaper Lyman fixed aperture disks, like this one: http://www.midwayusa.com/product/166087/williams-aperture-regular-1-diameter-target-with-050-hole-steel-black

So there is a POSSIBILITY that one could buy a 3/8x24 tap, the Merit adapter, and a Lyman disk to get the more desirable (for me) 0.050" hole in a 753 rear sight.  The rubber bellows from the 753 sights MIGHT fit the Lyman aperture disk, since both disks have an outside diameter of 1".  This setup would probably cost about $20 total, including the tap, and would be dependent on us hobbiest-gunsmiths being able to successfully re-tap the threads in the 753 sight (which is not a given by any means).  Or, you could just drill out the 753 threads to the smallest smooth hole that would accept the 9.5x1Merit adapter, and they JB Weld the adapter in place rather then screwing it in as designed.

It may not be worth all this and you might just say the heck with it, drill out the existing 753 aperture to 0.050", and hope for the best.  Worst case is you ruin things, and have to send Daisy another $35 for a replacement 753 sight (apparently they don't sell just the aperture, you have to buy an entire new sight).  Or, you could just use the 853 rear and front sights and give up on the 753 sights.  Or move your head uncomfortably forward to shoot (if you indeed have the same problem I do with the too-small 753 aperture hole)

[22junkie]

I think you will be better moving the rear sight back or remove a spacer on the buttstock.  Shooting prone puts your head much further forward than when you are standing.  You can get an adjustable iris also. I much prefer an adjustable.    http://www.champchoice.com/store/main.aspx?p=ItemDetailOptions&item=510

[22junkie]

When you can buy an adjustable iris like the Gehmann, Centra or Anschutz and the Gehmann is $52, why struggle with drilling out fixed irises?  Mine is a little more elaborate with filters and polarizer.   

[haertig]

What would it take to make that Gehmann iris fit into the 753 rear sight?  Are they the European standard 9.1x1 thread pattern?  Has anyone tried this to see if it fits into the close-but-not-exact 3/8x24 threading since the 9.1x1 taps are difficult to find?

[haertig]

The adjustable iris would be the best solution, by far.  I would pay the $52 for this.  But I'm not going to buy the matching Gehmann sight for $143 to make use of the iris, I would want to make the iris work on my 753 sight.

Another thing I've considered ... The too-small aperture on my 753 sight would work fine if I could move it closer to my eye.  I can't do that since the sight is already as far back as I can secure it.  But if I could extend the dovetail rail on the 853 further rearwards...

http://www.brownells.com/optics-mounting/rings-mounts-bases/rifle-bases/dovetail-scope-base-stock-prod40900.aspx



Maybe I could epoxy one of these dovetail blanks on top of my existing 854 rail.  Or drill/tap/screw it into place.  This would raise the rear sight some, I'd have to check if I have enough height adjustment in the sight mechanism to compensate.

But it's starting to look like the easiest solution might be to just put the original 853 sights back on the rifle and give up on the 753 sights.

[22junkie]

There are rails that clamp on.http://www.champchoice.com/store/Main.aspx?p=ItemDetailOptions&item=ASR10 also, the iris is 9X1 thread.  not sure of the daisy sight threads but you can call Daisy and if it isn't you could buy a tap and re thread.   

[ac12]

I don't know which 753 sight you have.
The 753 used a Gamo (Spanish) sight, prior to Daisy moving the manufacturing to China.  Daisy had serious quality issues after moving the manufacturing to China.  I don't know how is now, I hope it has gotten better.

I just tried the iris from my FWB and it screwed into my Gamo sight just fine.  Which seems odd if the threads are different.

I do not have the ability to accurately measure a hole that small, but the iris on my Gamo sight is approx 0.040 inch.

Here is some relevant stuff from the TargetTalk.org forum
http://targettalk.org/viewtopic.php?f=2&t=24616&p=124614&#

re: aperture size
After the 753 arrived and I shot it a few times it was obvious that the aperture supplied with the rear sight was too small. I tore the sight down and retapped the M9 aperture mounting hole to M9.5x1 so that I could use my Centra Iris.

re 9.5x1 tap
I could not find the correct tap but found that the standard 3/8 x 24tpi tap is so close that it worked just fine with both my Anschutz and Sentra iris.
I have encountered no problems with either of the two sites that I tapped with the 3/8" x 24tpi over the past year.