I have the Williams sight that you have on both my 48 and 54 and never had a problem with movement. The small screws on the side are not what holds the sight in place. Use them to snug to the rail and then tighten the screw that goes down into the base. You will need to remove the part that the peep aperture mounts on. The biggest problem I had was finding a replacement muzzle break that did not have the front sight mounted on a ramp. You might try UMAREX but I think that break has been discontinued.
The Williams aspect has already been well-covered here, so I will toss out that match sights can be lighter and less expensive than you think, if you keep an eye out for a good used one. A late Diana Diopter 75, just about any Anschutz sight, and the late "square" styled Walther LGV/LGR sights will all fit the Diana rail. The Walther and some Anschutz models are alloy construction, and surprisingly light and trim.
A sporter sight like the Williams has a great advantage for hunting or other true sport shooting, in leaving a better view around the target. But a match sight is a different level of quality and precision, with a world of cool accessories available, for target shooting or just accurate plinking. It's all in what kind of shooting you primarily do.
Any peep sight will use the very same line-of-sight as the original open sight. You must remove the rear open sight, or it will by definition cover the bottom half of your view through the peep. BUT--a good old-guy shooter's trick is to leave it on long enough to roughly align the peep first!
Agree on the target sights.
I recently installed a Gehmann Compact on my Avanti. A little over twice the price of the Williams...but man, is it precise. Carved out of a block of aluminum it is light and very well machined.
At 10m (it is a target sight) they say each click changes impact 2mm...and they are right...very precise.
And repeatable...during setup I specifically tried placing a shot then adjusting 5 clicks. Afterwords I moved back the 5 clicks and the pellet went into the same hole as the first, with virtually no shift.
As well it accepts antiglare tubes, filters and an adjustable iris.
Amazing value for the money IMO.
Do you have a good source for the Gehmanm Compact. When I was looking for match sights, I never saw that one. I was also considering the one being made for the Airforce Match rifle. That seemed to get good reviews.
From using the Williams, I do not really like it and would prefer better adjustment knobs.
I also tried a Swiss Elite, and it works great, but its true home is on my Anschutz 57.
Bill, Cibles Targetshttp://www.targets.ca/index.asp?Page=1 in Canada is where I got mine.
If you email them for info, the fellows name is Jocelyn. Very pleasant to deal with and reasonably priced.
It may take him a day or so to get back to you...it sounds like a one man operation and he has contract with the Canadian Forces which keep him quite busy at times.
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