No5 Foresight

I finally got sick of having to set the sights of my No.5 so high and so decided to do something about it.

Using Peter Laidler's excellent article here as a primer on the subject, I found out that my No.5, although sporting a foresight purporting to be a +0.045, what it really had was nothing of the sort - someone had ground the blade down until it was roughly a +0.015.

Again based on Peter's assertion that No.4 and No.5 blades can be interchanged, I went through my small collection of No.4 blades only to find that I only had bigger numbers than +0.015. However they appeared identical to the foresight blade sight in my No.5 and so I tried a test fit of two of them only to find that they slid rather too easily in the block.

So to the question (At last! some are already saying). Does the slot in the bottom of a new foresight sight sometimes need to be opened a little? I have seen some No.4 Mk.3 -0.030 blades (yes it shoots that low) at a reasonable price but would just like some confirmation that they will work.

Why not just grind the existing shortened blade down some more? Especially if it fits well.

I can't answer the actual question.

Yes, they definately DO need to be opened out occasionally. Put the blade part into the loose vice jaws then give a good thump with the tip of a screwdriver blade across the slot. This usually does the trick. But be warned that very occasionally, you'll get a brittle one that will just snap across the slot. But they're cheap as chips and plentiful.

Don't forget the magic Armourers formula, stamped in deeply across the frontal lobal brain area of all Armourers.
FORESIGHT INTO THE ERROR.
BACKSIGHT OUT OF THE ERROR

In other words, if your group is high, RAISE the foresight or LOWER the backsight
If your group is left, then move the foresight LEFT or the backsight RIGHT.

And if you are using a telescopic sight, ALWAYS treat the graticle as a foresight that MUST move into the error.

That's todays last lesson. Time to tidy up the class room, Chairs onto the desks, sweep the floor, books away and all be back on Monday morning at 0830 sharp.

In the meanime I'll be writing up my notes regarding patching up the draws for the No1, 4 and 5 rifles.