Viewpoint - British Army Contract for L96A1 Sniper Rifle (by Gil Boyd B.E.M)

[Lee Enfield]

I'm not sure that I would agree with that L-E, thread 108 above. There were in fact TWO locking rings available in much the same way that there were 4 bolt heads available for the L42. While this was a novel idea, it made adjusting the CHS a barrel removal job too! As for the interchangeability of the bolt and body, well, they were interchangeable......., but only in so far as they are also 'interchangeable' on the L42, L1A1 rifle, the Bren etc etc. They would change but would not necessarily be correct afterwards. That's the reason why the L96 bolt and hood were numbered.

I think that you must be reading a different EMER to me.

...snip...

that may be an example of practice vs. theory, but you can't do that with a Parker-Hale/Remington/Winchester/Mauser ect.

With them it's a case of cut & try, repeat, cut & try...

I watched an interview with Dave Walls where he stated that a current production bolt will headspace into any (same action) gun manufactured in c.1990...

I don't have EMERs on it, but I might have a few CFTOs and physical examples of Parker-Hale, Remington, Winchester, Mauser, AI AT and Lee Enfields ect....

[Peter Laidler]

I have to say that I haven't seen the video you both speak of. I just go from my memory, the repair information, the CES, the inspection standards, the operators instructions, the ESPD, the Gen Inst index etc etc.....

[Gil Boyd]

Roy,
Absolutely right Dave Walls oversaw what went on at Dartford the recommended MOD manufacturer, but they soon realised on acquiring two CNC machines that they could best do all this at Portsmouth and thats what they did...........don't blame them!

[Peter Laidler]

There was a big problem with material used early on that was at odds with the spec quoted and trialed. That resulted in the first '.....er........, back to the drawing board' moment.

Anyone interested in reading about that or is that all old-hat now?

[Gil Boyd]

Peter,
That would be interesting to hear the official version.

[Roy W]

Roy,
Absolutely right Dave Walls oversaw what went on at Dartford the recommended MOD manufacturer, but they soon realised on acquiring two CNC machines that they could best do all this at Portsmouth and thats what they did...........don't blame them!

But does anyone know which engineering firm in Dartford they used? Out of curiosity Gil

[sd4f]

Nothing to do with the production facility - the difference was 1 single new part:
From what I've read here, and everything I know about the AI, and other guns, the reason AI won was the locking collar that the bolt locks into which controls head spacing.

Basically by controlling 3 dimensions, you guarantee consistent repeatable headspacing.

By keeping the collar a consistent known value, and controlling the chamber and bolt geometry you guarantee as nearly as possible interchangeable parts.

ie, any AI barrel & bolt are interchangeable with any other.

pull an AI 308 barrel out of any existing rifle, or new off the shelf and once the torque value is the same, the headspace "Should be" exact.

basically they created a situation, where (as nearly as possible) the receiver is just another replaceable part. The AI AT and the AI AXMC have taken this to ne next logical step by formalizing the process.

Think of an AR15 barrel extension where the barrel extension is simply sandwiched between the receiver and the barrel.
ie. no short chambering, action truing, bolt lapping ect. necessary.

The thing is, what you've said literally applies to any firearm. It's not a factor of the design, but rather the design of the production and tolerancing, because if you control the factors relating to head space, to the same degree in other firearm, then you achieve the same result, complete parts interchangeability with consistent head space.

But the thing to take out of this academic discussion is that the others didn't do this, which meant their parts weren't interoperable and I suppose they were the ones whose production operations looked like garden sheds in comparison to AI, ignoring production scale.

Ultimately I've answered my own question, as it's not a matter of the functional design of the AI that won it over (I think that the reports establish that), rather the design of its production and parts supply chain. Fact of the matter is, any of the other rifles could have been manufactured to achieve the same level of parts interoperability, provided the critical dimensions were controlled... which they weren't...

[Gil Boyd]

BSA did go further and I think many thought it would win the tender, but Peter is currently telling the story from documents he has found.
In terms of the Dartford engineering company, not sure I'm afraid.

[Peter Laidler]

They CERTAINLY don't feature in any of the documentation - so far!

[Gil Boyd]

I'll ask Dave Wall