Sterling Mk5

[Peter Laidler]

I think that this has been mentioned here but did Canada have any L34 guns BAR? SF or the like? I ask because in the register were sales '....with gaps' and some large noticeable gaps!. Obviously these were sales via the UK MoD or Govt on a restricted Govt-to-Govt procurement basis where sales were logged in and out of course but further than that everything else was restricted. Not that it affected the book or any research but just out of interest it whetted my appetite............ Incidentally, there were no non-serial numbered guns that people who-need-to-get-out-a-bit-more speak of.

[browningautorifle]

I think that this has been mentioned here but did Canada have any L34 guns BAR? SF or the like?

There would have been some trial guns for sure, and someone mentioned that as confirmation. I never did see any nor did I know anyone that had. Too bad, I had one come past me a few years back and they're do-able...we should have had a small quantity... We didn't really have an "SF" until JTF surfaced and the Airborne was just that. They had mostly standard stuff. Mostly...

[Vincent]

And how about that brilliant design of the muzzle cap..... inquiring minds want to know.

[Brian Dick]

The design drawing of the muzzle cap is in the Technical Manual.

[Vincent]

Attachment 66082

Is this it?

[Brian Dick]

I think so. Did you reference the L34A1 Technical Handbook?

[Vincent]

I don’t have a copy.

[Brian Dick]

My mistake Vincent. I thought I sent you a whole set of Sterling L2A3/L34A1 literature several months ago. I still have them available if interested. As I've said many times before; I can't imagine doing these builds without the EMERs, technical handbooks, illustrated parts catalogues and even the user handbooks in the reference library.

[Vincent]

Oh! How that you mention it, I think you were going to send them along with another item. I am sorry. I completely forgot about them. I apologize.

[Peter Laidler]

Ah, yes, the muzzle cap. Remember that what follows is not a scientific paper or a classroom lesson. Ideally the subject would be discussed with the aid of the National Physics Lab high speed video and the component parts of the silencer unit spread out on the desk in front of you..........

The gun has just fired a single shot and the bullet has just left the confines of the spiral diffuser. As the gas enters the front plenum chamber (the gathering chamber shown in thread 15 above. Item 31 P179 in TGOD)) from the foresight mount block (TGOD; 36) and spiral diffuser (TGOD; 1), the gas enters the plenum chamber. It spreads out radially at 29 degrees and some of this now waste gas that we're desperate to get rid of overtakes the heavier bullet. As it does it meets with the specially shaped internal compound curvature of the muzzle cap (TGOD; 28). a very small amount of the gas that has passed the bullet will naturally emerge from the muzzle. A millisecond later, the bullet passes through the muzzle hole effectively sealing it. Remember this later........

Simultaneously, the waste gas remaining inside the silencer is directed by the internal shape of the muzzle cap to form a high pressure point centrally and directly behind the muzzle opening. This high pressure wave very effectively closes off the muzzle opening behind the projectile, sealing the unit and trapping the most part of the waste gas inside the front plenum chamber. Only then, a millisecond or so later the pressurised gas INSIDE the chamber neutralises/equates itself and as it attempts to revert to atmospheric pressure it simply takes the line of least resistance and vents to the outside atmospheric pressure and exits the muzzle as a puff of smoke.

So if you are looking at the slow motion video from the side, this what you'll see. First, there's the first feint puff of smoke followed by the bullet on its way silently to the unfortunate target at just below the speed of sound. Then - nothing..... but.......! Followed a short time/milliseconds later as the internal gas vents slowly and silently to atmosphere.

It's all down to the internal inswept design of the muzzle cap and the mathematically calculated area of the plenum chamber. There is absolutely no doubt in my mind that the arch genius George Patchett dreamed up this feature but that the NPL perfected it for him. There was a second design on offer by Sterling shown elsewhere in the book that eliminated the plenum chamber or extension tube (TGOD; 31) whereby the muzzle cap sat on top of the plenum chamber via a .75" or so long tubular ring that replaced the extension. But there were few, if any, takers. George Patchett had heard my oft repeated words. If it ain't broke, then don't fix it.........

If you liked or appreciated this short explanation, please tick the thanks box..........