Zeroing the No4(T) and No32 MK3 /III for the first time Part 1

[BazSmiles]

Was about to add to an old thread when a helpful Admin message suggested I didn't as the thread was rather old (104 months to be precise). For some of you this will be 'bread and butter' obvious, but even as an experienced shooter it was not obvious to me and might not be to others. A bit of fun if nothing else.

This new thread is about zeroing a 1945 dated, BSA made, H&H finished No4(T) rifle mated with a No32 MK3/III scope and bracket. You may have read similar before and this is not about replacing those threads or contradicting them but about my experience. Am new to ownership of a No4(T) having been giving extremely helpful guidance from Roger Payne and been supported by several RFDs who have been hunting out a rifle for me for the best part of 2 years; notably Stephen of Severnside Arms who succeeded. Both name drops are wonderfully helpful people and highly knowledgeable - thank you.

Here's an outline of what Part 1 is about: It's about the journey of taking a rifle from an unknown zero to a bore sighted point of collimation. By that we are talking about aligning the mechanical components of the complete system. In this case the centre of the bore to the very tip of the aiming post on the Mk3. Along the way have thought of 'Tips' to support other shooters. In Part 2 we'll find out just how good we have been in Part 1 when we visit the range and seek to zero.

TIP 1 - "RTFM" as my instructor said (Major Harveson) many years ago down at Hythe. So, read both Peter Laidler's books on the No4(T) and the No32 scope but also (if you use a MK3/III) the Infantry Platoon Weapons Pamphlet 10, Sniping. Mine is dated 1951. pay particular attention to 'zeroing' the rifle.



TIP 2 - Find someone who has done this before and ask them to show you.

TIP 3 - Acquire a .303 round complete. Inert or Drill might be an idea but as you have the rifle it is a fair guess you probably have a round to hand. Rename this round 'Tool No1, Mk3 scope Drum Adjusting' - as this should be all you need.


Step 1 (see Tip 1...): Took the rifle, checked it was unloaded, removed the bolt and magazine, mounted in a saddle-clamp already fitted to a telescope tripod, tightened up - headed out to the garden. Am fortunate that the land beyond the garden is also a permission; so useful.

Step 2: Balanced the rifle so that it was sitting level. The tripod has a bubble setup to help with that.


Step 3: Choose a vertically linear object that is at least 500m away. For me this was relatively straightforward as had a clear LOS out to over a mile. I chose the very tip of a chimney (to be know as target) at about 1200m.

Step 4: Trickier than you might think... Gently adjust the rifle until the dead-centre of the bore is aligned with the very tip of the target. All good? Check it again.


Tip 4: - Check the bore alignment. Look away. Check it again. Look away..etc.

Step 5: Look through the scope. Now where is that chimney? Ah, there it is. But it's not lined up with the post. No...it isn't. Rotate the deflection drum until the post aligns directly onto the target.


Step 6: Check the bore again. Look away. Check again. Still aligned? Good.
Now check the scope and post alignment. Both bore and tip of scope post should now be in alignment.

Step 7: Take a look at the deflection drum reading. As you can see from mine it was off by 12MOA.


Step 8: Do not touch these tempting mechanisms.


Tip 5: See Tip 3, you don't need a tool to adjust the sight you don't need pliers.

Step 9: Locate the drum bullet nipple and locate the tip of you round into the nipple.



Step 10: Sorry I couldn't take a pic of this...but I needed both hands. What's happening here is that I'm keeping the knurled/machine edge of the drum tight in one hand and slipping the deflection dial on the shortest route to '0' (zero) on the drum.
Here it is almost there.


Step 11: With deflection drum now set to '0' (zero) check the bore alignment to target. Look away. Check again. Check the scope post alignment to target. Should be aligned.

Step 12: The rifle bore and scope post should now be aligned. The deflection drum should now read zero. We now have a collimated bore and scope, we are bore-sighted and ready for the range. There are over 18 clicks of adjustment in either direction on the deflection drum after doing this, so run out should not be a problem.


In addition: Just to prove how robust this design is I unmounted the scope and then remounted it. Tightening the fixing screw to full hand tightness. The bore and scope remained aligned to the target. Part 2 will be zeroing on the range.
Look forward to hearing from you!

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[mrclark303]

Thanks for posting, it all adds to knowledge base.

I must admit over the years I've always bore sighted at 100 yards, why, I happen to have an open valley behind my house with a telegraph pole with a white square painted on it.

Just happens to be approx 100 yards away.

I use a slightly more 'Heath Robinson' approach, a step ladder and shooting bag.

The first time I used it was for my A4 Springfield build and it put me smack on target, just a few clicks of fine adjustment needed.

Since then I've used it for numerous rifle/ scope setups and it works every time.

[Westwood]

Awesome information that was shared. I sighted in my M47 T and at 100 yards but the dial said 150. I read this information and went downstairs and set it to 100 with no effort at all! Thanks for sharing!

[BazSmiles]

That's excellent! Really pleased you found this useful, thank you.
The reason for using 'over 500m' was simply because that is what was quoted in the manual.

[Peter Laidler]

If I might be so bold, might I suggest a simpler way Baz and others. You can do it in a classroom or workshop at 28 feet - or whatever that is in old money.. The simple instructions AND a calibrated colimation chart are shown in lthe EMER AND the No4T book. Alas, the chart in the book needs to be slightly enlarged from its A5 size to the EMER Foolscap size. But it works.
After that the rifle can betaken onto the range for accuracy and zeroing. Not the same thing incidentally.

When we ttested for accuracy and zeroed, we sent the rifles out with a card attached to the paperwork to the effect that 'SNIPER RIFLE. FINAL ZEROING IS THE RESPONSIBILITY OF THE END USER'. This little attached card gave the sniper the authority to book a range (they usually shared a 400 yard range and zeroed at that for a reason I won't go into...) AND an allocation of ammunition too!

You can tell such an Armourer zeroes rifle because due to the way we did it before the sniper got his mitts on it, the amount of clicks from STOP to 16 and 16 to STOP on the azimuth/ deflection scale would be the same......, within a few. Same as the range scale. STOP to 0 and 10 to SOP, the clicks are the same.

I agree with Baz with regards to the over 500 yard/metre guide. I'd prefer to go a greater distance, known to the other teccies and refer to it as 'THE KNOWN DAP, or Distant Aiming Point

Give Tony Harveson my regards.....

[BazSmiles]

If I might be so bold, might I suggest a simpler way Baz and others.....

Peter - thank you for the reply, it's great to have your expert insights; appreciated.
If I ever see Tony again would be delighted to say 'hello', he was a very precise but relaxed instructor; except on our test day, which was foggy... 1996 feels like a long time ago. Yes, familiar with 400m zero and purpose!