AIA #4 clone proofing

[harry mac]

They'd only pass Birmingham proof if they were exported to England, and that still is not a good judgment of function without it being checked for microscopic cracks.
Dimitri

That's exactly my point. They have been exported to The UK and are up to UK proof standards. If the rifles are strong enough to pass UK proof then there is no issue with their strength. As far as I'm aware UK proof standards are more stringent than SAAMI.

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[Dimitri]

If the rifles are strong enough to pass UK proof then there is no issue with their strength.

That is where your wrong, a proof load can be passed with a rifle of questionable manufacture that would not hold up after repeated firings.

Its like a weight lifter, a weight lifter can max out with 500 pounds and do it a couple of times without showing signs of not being able to, just as a rifle can handle a couple of proof loads, but when that same weight lifter does sets, he may only be able to do 250 pounds 15 times before having to stop.

Metal fatigue is the issue, not necessarily the rifle passing the proof testing. Especially when materials of questionable origin are used. Most military and commercial arms continue to use the same few materials as they always have because the arms designers know they work and will hold up in the long term with little to no metal fatigue from repeated firings, as well as can handle the pressures generated with proof loads.

Dimitri

[villiers]

That is where your wrong, a proof load can be passed with a rifle of questionable manufacture that would not hold up after repeated firings.

Its like a weight lifter, a weight lifter can max out with 500 pounds and do it a couple of times without showing signs of not being able to, just as a rifle can handle a couple of proof loads, but when that same weight lifter does sets, he may only be able to do 250 pounds 15 times before having to stop.

Metal fatigue is the issue, not necessarily the rifle passing the proof testing. Especially when materials of questionable origin are used. Most military and commercial arms continue to use the same few materials as they always have because the arms designers know they work and will hold up in the long term with little to no metal fatigue from repeated firings, as well as can handle the pressures generated with proof loads.

Dimitri

When this topic was previously discussed and I pointed out that my rifle had been proofed in the UK AND in Germany, I `phoned the Federal German proofing authority and was assured that proofing standards in the EU are NOT limited to proof firing the weapon. The action is removed from the stock and inspected for material damage, headspace is checked and the weapon inspected thoroughly. Proof houses in Germany and the UK have been doing their job for hundreds of years. They are government agengies and would be liable for any damage caused by their negligence.

So why should I heed the impotent bleating of self appointed "experts" who cast doubt on the reliability of an item that has not only been thoroughly proof tested, but has further stood the test of two World Wars?

[Alfred]

When this topic was previously discussed and I pointed out that my rifle had been proofed in the UK AND in Germany, I `phoned the Federal German proofing authority and was assured that proofing standards in the EU are NOT limited to proof firing the weapon. The action is removed from the stock and inspected for material damage, headspace is checked and the weapon inspected thoroughly. Proof houses in Germany and the UK have been doing their job for hundreds of years. They are government agengies and would be liable for any damage caused by their negligence.

So why should I heed the impotent bleating of self appointed "experts" who cast doubt on the reliability of an item that has not only been thoroughly proof tested, but has further stood the test of two World Wars?

I think you're conflating the previous discussion of WW2 era No.4 actions in 7.62 NATO with this No.4 styled but not actually No.4 or Enfield M10 action and its differing metalurgy and manufacturing techniques.

The basic Lee design elements remain, but this is not a No.4 any more than a No.4 is a Lee Metford.

A rear locking action is more subject to metal fatigue if for no other reason than much more of the receiver's structure is subjected to stress under pressure.
The receiver ring is highly unlikely to fail, because unlike front locking actions the receiver ring serves only to secure the barrel to the rails of the receiver.

The only real question as far as the M10 is concerned is how durable the alloy used in its construction is to repeated stress of firing the more intense .308 loadings or the highest pressure 7.62 loadings such as M118 Long Range Special Ball.

Proof testing eliminates the defective rifles, but doesn't predict the effect of continued use, and can't forsee abnormal conditions that a rifle might be subjected to. An example of such abnormal conditions came up on a long range brench rest forum recently. Ammunition loaded to maximum safe pressures where temperatures hovered around 60 degrees proved to be a dangerous overload when the shooter went to a match where temperatures approached 90 degrees.
A reported failure of a No.4 rifle using a European MkVIIIZ type ammunition suggested that the ammo had been developed for use in low temperatures and higher ambient temperatures resulted in excessive pressures.
A quoted reference to extra hot loaded MkVIIIZ ammunition in use in a desert environment told of extreme high pressures with the primers so flattened as to looked "painted on".

My opinion on the converted No.4 rifles proofed to the 19 T mark is that they should be safe enough with ammunition that generates pressures no higher than standard Ball Ammo, around 48,000 CUP which is equivalent to MkVIIIZ.

The question of whether the M10 action is strong enough for extended use of higher pressure loads like the M118 LRSB or the hottest commercial .308 ammunition will be answered with time and use by owners of these rifles.


As for casting doubt on the reliability of the Lee Enfield type action, no action type has a perfect safety record, The Ross debates provided numerous examples of LE action failures, and the warnings that SMLE action bodies can crack if a wet cartridge is fired indicate that theres always been concerns about the safety margin of the SMLE at least. The No.4 receiver and metalurgy are stronger than that of the No.1 in most cases, but the bolt itself is marginally stronger at best.


A rifle can last for generations if not abused by loads that exceed its design limitations. No sense letting emotional attachment or pride over ride common sense in chosing the best ammunition.

I wouldn't subject a 1893 Mauser to the highest pressure 7MM ammunition available today, I wouldn't subject a high number Springfield to the hottest possible .30/06 loads either.

[ireload2]

>>>They are government agengies and would be liable for any damage caused by their negligence.<<<

Just because the agency has fulfilled the requirement to proof a rifle does not mean they have any further liability. All they do is prove the rifle is not an immediate threat for catastrophic failure.
There is one case that I know of where the proof house struck the proof mark and cracked the receiver of an expensive rifle. The manufacturer had to pay for the replacement receiver. The damage was never noticed by the proof house or by the manufacturer. The odd thing is the rifle design was one which has the locking shoulders in the barrel extension. The receiver does not bear any load from firing. Yet the proof house had to stamp the receiver and they stamped it near the edge cracking it.