1944 BSA No4mk1 From Bubba Sporster to T-Replica

This rifle was discovered amongst a trio of “sport” No4 rifles at a local gun show. All exhibit the same treatment – cut forward wood, stripped of the upper wood but the receiver and barrel was as per the factory and uncut, undrilled and suitable for resurrection.

The 1944 BSA produced No4mk1 was chosen for conversion to be a “T-replica” for a dear re-enactor friend. This was the original factory mark and version used to select the Holland and Holland “T” sniper rifles from 1944 on. This example still bore its original serial numbers, factory marks and had been through an FTR (Factory Thorough Repair) at the Fazakerley plant in 1948.


To replace the wood a complete setoff NOS Fazakerley beech wood was selected, this was made after WW2 to repair such rifles and give the factories in Britain work to do. The NOS furniture was carefully fitted to the original standards for stock bedding – contact patches around the main body and magazine well producing 3 to 5 pounds of down pressure on the muzzle bearing.


The mechanical functions of the rifle's systems and components were also checked, dissembled, cleaned, inspected and measured. The bolt has several components with specific characteristics and functions that all checked out: locking lug contact, striker lift and clearances, striker protrusion and shape, striker spring strength, ejector spring strength. The bolt head was updated to tighten head space slightly – achieving a “go” and “no go” pass for the British armourer’s gage sizes. Within this work was the selection of a bolt head with minimum "over-turn" – this provides clean transfer of firing forces from the cartridge to the bolt flange to the bolt body and locking lugs – less movement play here gives overall good precision.


The fit up of the components is described within the original EMER instructions (which are available for every technical device used by the British army and repaired / maintained by the Royal Electrical and Mechanical Engineers (REME.) This includes the material, lubrication and tools for repair , how to repair any broken components and even details such as which way a screw head should face (like on band and sling swivels). I personally like to leave all screw heads aligned with he axis of he rifles barrel or perpendicular to it (without under or over tightening). I also use purified turpentine, raw linseed oil and high temp graphite greases as prescribed.


The front sight blade has to be removed to allow the upper rear wood band to be passed and positioned around the barrel. New parts to the build are becoming evident.

New fore-end viewed from the RHS. Head Space Gauges in the charger clip, vernier caliper to make key measurements.

First fit-up of a NOS butt stock. The gap between butt stock and receiver ring shoul dbe the thickness of a hackaw blade to avoid splitting under recoil. Note the large antique screwdriver to drive the butt bolt home. A selection of new Bolt Heads in the container to select the best example for head space and bolt head overturn.

Our subject rifle inthe middle of this group shot at the range for a test and tune day.

I like to range tune each rifle for function and performance. The BSA did not do so well on its first range trip – it functioned perfectly, however the fall of shot was significantly low, starting at 25 yard then 50 and targeting an effective 100 yard zero. While the precision of the groups was acceptable from the start – less than 6 MOA, its location (accuracy) became the focus.


Doing the ready math it could be determined that the Point of Impact was 27 Minutes of Angle (MOA )low – this necessitated a shorter front sight blade some 5 size increments shorter (0.075”). It originally had a +0.015” front sight blade. I happened to have a Parker Hale made – 0.060” sight blade in stock – some would say that these do not exist..


With the desired zero (actually at 200 yards) to match the lowest mark on the rear ladder sight, an effective 100 yard zero can be found by clicking down the 3 additional clicks available below this mark, this will also be the rough first intersection of the bullet path at 25 yards also (first intersection as the bullet rises to cross the point of aim, the second intersection is where the bullet then re-crosses the point of aim at each range).


Other features of the build so far: Original Triangular Sling Swivel at the front trigger guard screw, reproduction 1907 leather sling. Matching Beech cheek piece, custom profile fitted to the butt stock and affixed with authentic steel slot headed screws. The rear ladder sight had its battle aperture ground flush to allow the telescopic sight to fit low and close to the receiver as per the original. I also added a 16 gauge bushing to the peep hole in the sight slide to reduce its diameter for better target work.



The owner of this rifle has had the opportunity to shoot it twice during this project so far. The second meeting was much happier as all the tuning was coming together. Despite the 35 degree F conditions he settled in to shoot this fine 4 round group using the iron sight at the 2” bullseye at 50 yards. Just like the British Army Sniper he can also give personal preference feedback to be incorporated into the build and characteristics of “his” rifle. He liked the iron sight improvement, the sling and the position of the cheek piece, but asked for a smoother trigger pull – this can be achieved by working on the finish and angle of the cocking piece tang.


The intention is to now set this rifle up as a T-replica, by drilling and tapping (also soldering in place) for the authentic scope pad, bracket and scope.

The first choice was to review the Sarco No32 Mk1 reproductions.


The work involved is to put the center of the telescopic sight tube (with its reticle adjusted exactly concentric to the scope body tube ) exactly over the center axis of the rifles barrel. In this design the front pad and attachment screw controls the left to right position of the scope axis in relation to the rifle barrel, the rear pad controls the elevation angle of the scope axis in relationship to the expected British 303 Mk7 ball ballistics.

On the original rifles the boss for the font pad was roughed in and its finished shape and datum (diameter and face) were machined on after assembly, similarly the vee-groove in the rear pad was also machined on after assembly.

Al the reproduction examples have these features ready finished and the pads must be attached in the exact position required from the start. This is very much like the instructions for reattaching an original pad that had become detached (which they did) as described by the EMER. In other articles I will be comparing original and various reproduction scope brackets, pads and even scopes.

For this rifle build suffice it to say the cheapest reproduction parts have been put aside and more authentic parts are being sourced from individuals in Canada and the UK (both with spectacular personal histories providing for these arms while still in service).


An original No32 mk3 scope on top, the Sarco steel reproduction No32 mk1 scope on the bottom.

The scope that will be initially used will likely be one of the current reproductions, although any practical solution will be provide to close the accuracy / authenticity / performance gaps observed.


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