The UK's Finest Independent Forum for Shooters and Gun Owners. Est 2010.

Proof originated in the days of wrought iron barrels. With iron, it is possible to have strings of slag in the metal and proof was the only way to detect and eliminate these.
With modern steels, all that proof achieves is to overstress the parts of the gun and this dramatically shortens the fatigue life. If you subject an old gun to re-proof, you are doubling up on this vandalism.
Fred

It also tells you if the maker got it absolutely right in the first place..............it is a contained pipe bomb, after all.
And my experience working in QA labs tells me that modern steels can also fail................

Pete

Pete wrote:It also tells you if the maker got it absolutely right in the first place..............it is a contained pipe bomb, after all.
And my experience working in QA labs tells me that modern steels can also fail................

Pete

how high a percentage rate of failure are we talking Pete?

Sixshot6 wrote:

Pete wrote:It also tells you if the maker got it absolutely right in the first place..............it is a contained pipe bomb, after all.
And my experience working in QA labs tells me that modern steels can also fail................

Pete

how high a percentage rate of failure are we talking Pete?

and how much is the failure rate increased by repeated overpressure events ? strange that few other countries bother with proofing now ?

I can’t remember when or from whom I heard it, but an engineer in the motor industry stated that when developing new parts, drive shafts and the likes, the industry profs those parts as part of the development process to ensure they can take the most excessive loads that they may ever encounter in use on the road. Sound familiar? Just like gun proofing.

The big difference is that these parts would never see use in an actual vehicle because of the destruction at molecular level they would have suffered! But we then shoot them...!

Sim G wrote:I can’t remember when or from whom I heard it, but an engineer in the motor industry stated that when developing new parts, drive shafts and the likes, the industry profs those parts as part of the development process to ensure they can take the most excessive loads that they may ever encounter in use on the road. Sound familiar? Just like gun proofing.

The big difference is that these parts would never see use in an actual vehicle because of the destruction at molecular level they would have suffered! But we then shoot them...!

FredB is who you heard it from.

Sim G wrote:I can’t remember when or from whom I heard it, but an engineer in the motor industry stated that when developing new parts, drive shafts and the likes, the industry profs those parts as part of the development process to ensure they can take the most excessive loads that they may ever encounter in use on the road. Sound familiar? Just like gun proofing.

The big difference is that these parts would never see use in an actual vehicle because of the destruction at molecular level they would have suffered! But we then shoot them...!

As an apprentice, at college we had guys from Hawker Pacific Aerospace, who specialised in landing gear repairs, they all spent time in the testing dept, and all parts made were x-rayed and scanned. 1 in 10 were the destructively tested. no part put under stress was ever fitted to an assembly. I remember this as at the time, they all saw it as a huge waste.

I also know a couple of people that work for Martin Baker. again, all parts and chairs are x-rayed and ultrasonically tested, and high number of samples are stress tested and destructively tested. those parts do not go into chairs, they are destroyed.

yet this country seems to have it enshrined in law that this testing is to be done and then used. i'm sure x-rays or ultrasounds would tell them far more that an over pressure charge and a visual inspection.

bradaz11 wrote:
yet this country seems to have it enshrined in law that this testing is to be done and then used. i'm sure x-rays or ultrasounds would tell them far more that an over pressure charge and a visual inspection.

Come on now - they though long and hard about this when they set up the charter in 1637. It worked ok then, stopping those nasty johnny foreigners selling their cheap guns here whilst protecting the London gun trade, nothing much has changed since then.

Sim G wrote:I can’t remember when or from whom I heard it, but an engineer in the motor industry stated that when developing new parts, drive shafts and the likes, the industry profs those parts as part of the development process to ensure they can take the most excessive loads that they may ever encounter in use on the road. Sound familiar? Just like gun proofing.

The big difference is that these parts would never see use in an actual vehicle because of the destruction at molecular level they would have suffered! But we then shoot them...!

I'm an engineer in the medical device industry and this is similar to the fatigue testing of implants. The testing is performed as part of the design validation phase to ensure the design has no inherent fatigue issues. The processes to make the implant are also validated to ensure that the process remains in control, and therefore always produces acceptable components, therefore you do not need to perform this destructive fatigue testing on every single part.

It puzzles me as to why this approach isn't acceptable for the firearms industry, surely you are potentially introducing unnecessary stress into the firearm which could fail during normal loadings at a later date especially older firearms.

Whilst the system is antiquated and has its flaws, i think we’ve all seen or heard of some very poor examples of gunsmithing over the years.
If gunsmiths worked to the standards of the aircraft,medical implant, motor industry etc. Had the various controls and quality standards in place then , self certification would no doubt be applicable. As far as i’ aware just about every pressure vessel has to go through a test procedure that includes a test over and above its working pressure , and in the case of gas cylinders this is repeated at intervals.
Given that many shooters handload, it is quite likely that some loads exceed the design parameters for the cartridge/chamber in question.
The gunsmiths i’ve used are usually far more concerned with the physical damage the proof house inflict on firearms through careless handling and packing rather than the effects of proof.
Also in the unlikely event that a firearm failed catastrophically causing injury to anyone close by, a lack of proof would give any insurer instant wriggle room in the event of a claim.
Though must be said if i owned an old gun i cared about, not sure i’d be too keen putting it through proof again.