Author Topic: Daisy 753 Precision Diopter Sight Revisited  (Read 2577 times)

Offline Fatman

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Daisy 753 Precision Diopter Sight Revisited
« on: January 19, 2010, 10:46:59 AM »
Hi!

I’ve posted on this topic in the past and thanks to all who took the time to read my post.  Here’s an update on a recent purchaseby a friend of the 753 “Precision” diopter sight and matching front direct from Daisy.  

My shooting buddy Jack , who got a Daisy 853 on my recommendation decided to upgrade from the stock 853 sights.  The 853 rear is good, but it is easily damaged with rough handling and has a lower sight line than the 753.  Plus it lacks the “*_*_*_*_*_*y” rubber eyecup.

The 853 front is another story.  The inserts are crude, unevenly punched, off center and appear more oval than round.  The housing is crudely made and often won’t hold the inserts securely.  (The easy fix for that is to bend the little retaining tabs on the inserts back a bit so they take up the slack.)

The higher sight line if the 753 sight is more comfortable for most adult shooters.  You don’t have to crane your neck so far over.  A more upright head  angle also helps to control sway for a more stable stance.

When asked by my buddy what I thought, I (foolishly) recommended that he get the matching 753 front and rear sights from Daisy and save a few bucks.  My recent experience with one that was given to me, along with the general consensus that the QC on these Chinese copies of the Gamos (which are a cheap copy of an older German design) was the basis for my recommendation.  

Now this is the same friend that I steered to  Numrich Arms for their 753 Target stock at a knockdown price - which turned out to be identical to the 853 with a 753 part number.  I don’t think it was a scam, he said that it had the correct part number on it. (In all fairness to Numrich Arms, they don’t make stocks, they sell merchandise sourced from various manufacturers.  In this case, probably Daisy’s supplier or even Daisy themselves unloading old outdated inventory.  Styles, part numbers etc. change over time and the stock was probably as advertised but not as expected.)

Well my buddy shows up this morning with his new “Take Pride it’s a Daisy” Precision Diopter and a worrisome look on his face.  And yes, I did it again (you’d think I would learn).  There was very noticeable slop in the eyepiece.  You could wobble it side to side (horizontal plane)  almost 1/16”!   In the vertical plane it was ok with no noticeable wobble.

So, send it back and risk another one from Daisy?  Get a refund, bite the bullet and get the Gamo at three times the price? Or see what can be done to correct the situation?  Feeling a more than a little guilty, I agreed to see what I could do.

The eyepiece carrier rides on two vertical and two horizontal shafts, with one of the shafts in each pair being threaded allowing adjustment.  The carrier slides on the fixed shaft and the threaded shaft controls its position.  On this example the horizontal shafts and bores were good with no noticeable play so there was no wobble in the vertical plane.  

The slop in the horizontal plane, was caused by a poor fit of both vertical shafts in the housing.  Both vertical shafts are held in the housing with tiny E clips at the bottom of the housing.  The fixed shaft has a small stop flange at the top keeping it in place (sort of like a rivet).  It doesn’t move so shimming it is easy and a drop of Super Glue will keep the shims in place. You could probably just clean it off and Super Glue the ends in place, making sure that none gets on the bearing surfaces of the shaft.

The threaded shaft rotates in the housing which is more problematic.  The correct fix would be to drill out the housing and epoxy in a brass plug or peen in a brass “rivet“, drill and ream to fit the shaft, lubricate and reassemble………….not likely!  I lack both the skill and equipment for that kind of work and frankly, the value of anyone’s time who does, would far exceed the value of the sight in the first place.

Soooo… little collars formed around the shafts from brass shim stock (I have a small assortment of brass shim stock which I got from my local hobby shop.  It contains several small sheets of various thicknesses  and cost around 3 bucks.  I cut the shims from the thinnest stock with scissors.)   A little trial and error filing with a round jewelers file and a few test fits and all noticeable play is gone.  Clean up the housing  of filings, degrease the holes, the outside of the shims, and the area right around them.  Lubricate the shafts well and reassemble leaving off the E clips.  Carefully position the collars flush with the outside of the housing.  Sparingly apply Super Glue around the collars inside the housing. (I used a tooth pick and the liquid Super Glue not the gel.  For me, it seems to migrate into the joints and to hold better than the gel which tends to only stay on the surface.)  Careful to keep the glue off of the shafts (the lube will keep the glue from adhering ).   Make sure the shafts rotate freely, re-attach the E Clips.  Snap on the sheet metal housing and screw in the eyepiece.

Was it worth it?  I guess if you already have the sight, it has noticeable play in it, and you like to tinker, yes.  The fix should be fairly permanent as the areas aren’t under a lot of stress and the brass is a better bearing surface than the pot metal housing.  

If you can afford the Gamo version, it certainly makes more sense.  I certainly haven’t seen any complaints about them.

Cheers,
Fatman

Offline Fatman

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RE: Daisy 753 Precision Diopter Sight Revisited
« Reply #1 on: January 21, 2010, 09:55:56 AM »
Moderator:

My bad.  Never dreamed that would need censoring (5th line down on original post).  My apology.

Please replace the censored word with "desirable"  (adj. 1. worthy to be desired: pleasing, excellent or fine).

I have far too much time on my hands.

Thanks,
Fatman