Rear Sight Width

[Bunsen]

I have an FWB P34 pistol. The width of the rear sight is adjustable.
Are there any recommendations as to how wide I should have the slot compared with the width of the forsight? At aim I can set it to match the foresight or open the gap to show a small amount of target as each side.

Which is more accurate?

Thanks

[Rutty]

Having too narrow rearsight will be more disadvantageous than having one that is too wide. So, start with a rearsight that is a least twice the width of the foresight; i.e. half foresight width of white on each side; and see how you get on. Depending upon how steady your hold is you may wish to widen it slighly or make it a little narrower. But, whenever you make a change make sure that you allow enough time to properly evaluate its effect, good or bad, before making any further adjustment.

What I have said above only applies to one set of conditions. If you shoot on different ranges with varying lighting you may well find that you need to alter your sighting setup slightly.

Rutty

[RobinC]

I endorse what Rutty has said but I think he meant visibly twice the perceived gap at the rear not actual measurements, that would be a massive gap. I run what are considered wide gaps on my pistols, with an average sightbase for example I'd have a 4.8 mm wide forsight with a 5 mm rear gap which gives the picture of the sight in thirds with the observed gap either side similar to the width of the observed forsight.
I'm not sure thats any clearer! But anyway go big foresights and big gaps most people prefer it although it is personal preference and you'll always find someone who uses tiny gaps.
Good shooting,
Robin

[defblade]

Tiny gaps means the foresight blade will overlap the edge more easily. Once it does, it's hard to tell by how much and so correction is more difficult (and overcorrection leads to the same problem the other side). So although tiny gaps would seem to be more accurate, you'd need a very steady hold to best use them.

Also, the brain is surprisingly good at balancing one thing against another, and at finding cn=entres (which is why the target doesn't need to be in focus - you can tell the centre of a fuzzy blob just fine) so it's fairly easy for most people to know when the blade's in the middle of the gap even on a large gap (keeping it there's another thing ).

[John Marchant]

As has been mentioned, as a good starting point, measure and set the gap of the rear sight to be the same width as the foresight and then make small adjustments afterwards.
It is also wise to "lock" the adjusting screw after adjusting as these have been known to gradually vibrate out to a larger width setting. A simple application of nail varnish, to your choice of colour, will help to lock the adjusting screw sufficiently, whilst still allowing future adjustment if required.
DO NOT use any form of "thread lock" as this could cause future problems if you require to make adjustments.