Depending on skill level what should the front aperture size be? I could have sworn that the Heinz Reinkemeier books had a recommended sizing chart based on scores being shot but I have not been able to find it. Looked all through my coaching stuff and can't find it either.
On paper targets I'm sort of a high sharpshooter - low expert (most of my targets are mid to high 80s with some in the 90s). I just got a FWB 800 that came with a 4.0 front sight. The sight radius at a nominal 30" and I'm thinking this front sight might be a little too large based on how I'm shooting. My other air rifle has a variable aperture and I crank it down a little more than the FWB, but I'm not sure the scores are any different.
It got me thinking though, what size is appropriate for what level of shooter skill. Anyone have recommendations?
I am currently trying to deal with this issue and am no expert. i asked on this forum and got some advise which so far seems to be correct. from what I have read and been told the aperture size is not dependent on your skill but rather on the distance between your front sight and your eye and I also believe, the size of the bullseye. generally speaking I have been told that most shooters try to set to front aperture too tight so actually bigger may be better. Generally the rule I have been told is to leave about three minutes of space between the bull and the front aperture. I was on the range this morning shooting smallbore and it seems to me that the smaller bulls can be shot with smaller apertures as a rule of thumb. I think some trial and error is required.
I can tell you that I am old and my skill level with my air rifle is similar to yours. I use a 4.3mm front aperture in my 6834 anschutz sight set at 10m . On a standard 100 yard smallbore target my front aperture (with smallbore) is even bigger.
I am not a detail guy. I am a generaiities typr guy. look for some articles by JP O'Connor.
Rick Bassett
That's some great information, thank you both. I actually have that article as a .pdf in a folder on my computer, but I don't think I had read it yet. It has some really good information, as does the No. 3 article referenced in the article.
It looks like the chart shows that a 4.0 would be just about perfect, but I'm going to keep experimenting. I have a variable sight aperture in an another sight base and I might just swap it out on the FWB. I will say that I don't like a super thin aperture, I find it hard to focus on.
If I'm reading the chart correctly, the numbers are the minimum not the optimum, ie you may need a larger size. Practically you want the foresight aperture to be large enough that it doesn't overlap the foresight as you aim. Remember the inside edge of the foresight isn't sharp; it may look so, but it's actually blurred by light diffraction. You want this blur to be well away from the target for two reasons: 1) The blur can trick you into overlapping the target ; and 2) the blur makes the gap around target less bright. In simple terms we see brightness better than distance, so a bigger gap helps us centre the target; if the foresight is off centre the gap will appear brighter on one side.
From memory WOTR recommended a 4.5mm for 10m air. If your hold isn't perfect, going bigger, within reason may help.
Tim S wrote: ↑Mon Apr 03, 2023 9:36 pm
If I'm reading the chart correctly, the numbers are the minimum not the optimum, ie you may need a larger size.
Correct! I keep the size chart handy for my junior rifle team. Easy rule of thumb if you are measuring in inches: The distance from front sight to the eye (not rear sight) roughly corresponds to the size of aperture.
Lets say the distance from the front sight to eye is 38 inches. Then the size of the front aperture should be 3.8 at a MINIMUM. It can vary some especially on the shorter rifles for smaller juniors.
For beginners the aperture size for standing should generally be larger than the minimum because of the need to keep the black of the target inside the front aperture as much as possible. For the more experienced shooter the aperture can be smaller but can vary based on lighting conditions... minimum size for bright conditions and larger if lighting is poor.
I'd add that in my experience the thickness of the foresight ring itself affects the aperture, the ring ang gap should balance each other. An iris, like the OP has, typically has a fairly thick ring (1.6-2.0mm), and calls for a larger aperture (after accounting for hold). A few years ago I switched from glass hi-ends to a glass iris just to get a thicker foresight; I had to bump up the aperture from 4.5 to 4.7-ish going g from a 1.4mm ring to a 2.0.
Tim S wrote: ↑Mon Apr 03, 2023 9:36 pm
In simple terms we see brightness better than distance, so a bigger gap helps us centre the target; if the foresight is off centre the gap will appear brighter on one side.
From memory WOTR recommended a 4.5mm for 10m air. If your hold isn't perfect, going bigger, within reason may help.
Ok I see what you are saying. Interesting comment about seeing brightness rather than distance. I never thought of it that way, but I have to agree. My hold is far from perfect, so maybe a little larger aperture is one I should try.
I have been shooting aperture front sights for many years (honestly it's been decades), almost exclusively variable apertures. I've always chosen a size based on perceived movement and psychological/emotional comfort. Too tight and the perceived movement makes the anxiety go up, and my ability to break solid shot goes down. Depending on my holding ability for the day, I'd adjust it a little bit to what felt right.
That being said, I'm not sure what felt right produced the best results.
bdutton wrote: ↑Mon Apr 03, 2023 9:51 pm
Correct! I keep the size chart handy for my junior rifle team. Easy rule of thumb if you are measuring in inches: The distance from front sight to the eye (not rear sight) roughly corresponds to the size of aperture.
Lets say the distance from the front sight to eye is 38 inches. Then the size of the front aperture should be 3.8 at a MINIMUM. It can vary some especially on the shorter rifles for smaller juniors.
That's a very useful rule of thumb. I'm writing it down in my coaching notebook.
