L1A1 SLR Stripping & Re Assembly Of ABS Butt Group

Tools & Equipment

Before starting work it is wise to make sure that you have the following available.

a. Return Spring & Butt Spanner  (B2/1005-99-960-0100) (the ‘T’ tool).

b. Large flat point screwdriver to fit the butt plate screw.

c. Flat point screwdriver to fit the butt tang screw (this is on the underside of the butt where the butt joins the lower receiver)

d. A suitable ‘hook’ tool for removing the butt plate plug from the butt plate once the butt screw is removed.

e. Where possible a firmly mounted vice with ‘soft’ faced jaws. Whenever possible the optimum way of mounting the rifle in the vice is to clamp the upper receiver in the vice, using the right side wall of the magazine housing only. The vice should be mounted so that there is a minimum distance of 1 Metre to the right of the vice which is free of obstructions.

To Strip The Butt Group

1. Cock the rifle, open the rifle and remove the breech block and carrier, and the top cover. Having done this close the rifle and make sure the upper and lower receivers are firmly locked together.

2. Lift the carrying handle and using the right side wall of the magazine housing ONLY, clamp the rifle in the vice with the bottom of the side wall horizontal (muzzle down, butt up).

3. Using a suitable flat point screwdriver unscrew the butt plug screw and remove it. 

4. Using a suitable hook tool, (or, if the plug is loose, the screw) prise or pull the butt plate plug from the butt plate and remove it. 

5. Insert the ‘T’ tool into the opening in the butt plate. The spike part of the tool should pass easily through the hole in the return spring nut. Using light forward pressure on the tool, turn the tool slowly until it engages in the slots in return spring nut.


6. Keep firm forward pressure on the tool and unscrew the return spring nut.  IMPORTANT; Whilst unscrewing you must keep a firm forward pressure on the tool. Once you feel that the nut is completely undone, make sure that there is nothing in your way, make sure that you keep a firm hold on the tool, and in one swift movement withdraw the tool which will now be under spring pressure! 

7. Once you have withdrawn the return springs enough to release the pressure, pull them clear of the butt (still on the tool) and lay them to one side. Note; they will be covered in dirty oil/grease so have some old newspaper or similar ready to put them on. 

8. The butt plate can now be pulled clear of the butt. NOTE; there may be one or more thin washers or shims present on either the return spring nut or the butt plate. If so the butt plate should have been marked with a small ‘x’ (although this is not always the case). If these shims are present, carefully remove them and put them safe. 

9. Remove the rifle from the vice and turn it upside down on the bench. Using a suitable flat point screwdriver, unscrew the butt tang screw. The butt can now be withdrawn from the return spring tube by pulling directly away from the rifle. Note that this may be quite stiff. Once free of the rifle place the butt flat on the bench and undo the butt swivel screw to remove the butt swivel. 

To Re Assemble The Butt Group.

A. Re assembly is in the reverse order to stripping, however the following notes should be used to make the job easier and avoid problems later. 

B. Before starting, make sure that everything is clean. The return springs should be carefully separated from the plunger.  They are held onto the plunger by a reduced coil on the end of the springs, to remove them hold the springs in the left hand level with the shaft of the plunger and twist the plunger while pulling it clear. Wipe down the springs with a clean rag. It is advisable to wash them using WD40 or similar spray penetrating oil and allow them to drain. Oil with a light rifle oil before re assembling the plunger.

C. Clean the exterior of the return spring tube with a clean piece of rag and then coat with a very light smear of general purpose grease. The interior of the tube should be brushed through and polished with a chamber brush on a rod before pulling through with clean flannelette and lightly oiling. NOTE; only use a light oil for the return springs, using grease may lead to a hydrostatic lock in the tube which will make the action very sluggish.

D. If refitting the same butt and butt plate ensure that any shims that were originally fitted are used again when rebuilding the butt group.

E. When refitting the return springs ensure that the return spring nut is properly seated before screwing it home. If after one or two turns it becomes very stiff, remove it immediately and check the screw threads for damage before refitting.

F. If a new butt or butt plate is being fitted, if it is found that once the return spring nut is done up tight the butt plate is still loose, shims will need to be fitted underneath the return spring nut. This is trial and error adding one shim at a time and testing the butt plate for tightness. No more than 5 shims should be fitted. If more are required either the butt or the butt plate should be replaced with another.