Sterling Mk4/L2A3 trigger en bloc

[tankhunter]

The butt main frame was always difficult to straighten properly. In fact I don't ever recall attempting to fix a buckled one because, so I'm told, they were double ended - in that the frame had to operate and lock properly at the folded and opened position and if you dollied it straight, it might be STRAIGHT but if, in doing so, extended the length of one leg over the other (heat and hammering) it'd upset the alignment geometry. Nope......, never straightened the main frame as I recall. For a long time there were no complete butt assemblies so it was always a case of demanding parts to repair or build up the one that was damaged

AND made even MORE difficult/ impossible. When the later modification of the Butt strengthening 'Y' fillet plate was installed! This was a 'stiffener' plate to prevent distortion in the 'U' section of the Butt assembly. M.

[Peter Laidler]

I'd forgotten about that yoke mod Tankie...... Mind you, that was marginally better than ring punching the axis holes! I could never understand why they just didn't do what they did in NZ. Just ream out the oversize holes, insert and soft solder brass bushes in place and make good! Permanent repair! I think that Sterling eventually did this during their equivalent of FTR for nations needing guns rebuilding.

[tankhunter]

Agreed Pete! I mean, Ring Punching! What a bodge! Never lasts & fails to do the job for long!

Yes I concur, reaming & bushing would give the stocks a new life. & was indefinitely repeatable, if require?

Do you remember cutting circular shims. To insert behind the trunnion projections? This tightened up any sideways movement of the stocks that were worn. CONSTANTLY doing this for shooting teams! ....... Although, it always made me smile. at the thought of trying to get 'sniper' like accuracy. From SLR Rifles & SMGs! .........'Ah, Happy Days'!.....

[Vincent]

AND made even MORE difficult/ impossible. When the later modification of the Butt strengthening 'Y' fillet plate was installed! This was a 'stiffener' plate to prevent distortion in the 'U' section of the Butt assembly. M.

I had always looked at it as an improvement. An Armourers perspective is quite different. It would never have occurred to me that the stiffening “Yoke” made repairs more difficult.

I'd forgotten about that yoke mod Tankie...... Mind you, that was marginally better than ring punching the axis holes! I could never understand why they just didn't do what they did in NZ. Just ream out the oversize holes, insert and soft solder brass bushes in place and make good! Permanent repair! I think that Sterling eventually did this during their equivalent of FTR for nations needing guns rebuilding.

The bushing is a great idea. I will give it a try. Much better than welding the hole closed and drilling a new one.

The butt retaining pins seem to be the first thing to wear and create play. A brass bushing would probably help alleviate that too. I am guessing Armourers had a supply of pins. There are none to be had here, so I make them. I see some folks threading the trunnion and using machine screws.

[Peter Laidler]

Do you mean the little thin pin things? They were a stock size as I recall so should be available as a rod. We were taught to squash one end a bit so that the pin would tighten up in the hole.

[Vincent]

Do you mean the little thin pin things? They were a stock size as I recall so should be available as a rod. We were taught to squash one end a bit so that the pin would tighten up in the hole.

No, not the little locking pin. Though that is a good tip. I am talking about the other pin, the big one that keep the butt on the trunnion.

[tankhunter]

No, not the little locking pin. Though that is a good tip. I am talking about the other pin, the big one that keep the butt on the trunnion.

I THINK you are refereeing to pin, axis, butt? The domed headed axis pin. Well....it is NOT these that wear If you remove the butt assembly. You will see that it pivots on a 'stepped' shoulder, that goes THROUGH The Butt Axis Holes. It is these 'shoulders that wear, & not the pins!

Hence rebushing the holes in the stock, to match the worn stepped axis hollow protrusion's. Also I mentions cutting round brass shims. These took up the wear on the between the side of the butt axis pin hole. & also wear on the flat face of the base of the 'stepped' protrusion. Thus preventing sideways movement of both butt ' Bars.

[Vincent]

Thanks. It sounds like I should just replace the ‘butt pivot’ with a newly made one. We call it a ‘trunnion’ over here. Not difficult to make. I could do away with the pins and use e-clips, like on the Canadian C1 SMG.

[Vincent]

Is this the bushing modification?



It looks like the bushing is welded in.

[browningautorifle]

do away with the pins and use e-clips, like on the Canadian C1 SMG.

I had forgotten that...