DP markings

[gerard488]

The sequence of marking is confusing in some ways so here is what I am wondering about: Acceptance marks are made when the rifle enters military service
DP marks are made while it is in service
Proof marks are made when it leaves service


My rifle is Stamped "DP" on top of the receiver. Am I correct in saying this was done by military examiners/inspectors?
The same rifle has proof marks, Am I correct in saying that the proof marks were stamped when the rifle was released from military service? Therefore ,would it be true that the rifle was inspected and safe when sold from military service?
If so, why was the DP not removed or crossed out?
How can I tell if the proof marks were made after the DP marks?
I can post pics of the marks if needed
Thanks in advance,, I know Peter will have the answer.

Information

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[Robert303]

It has all been said before. Look up DP marking in the search box. The Rifle may have survived the firing of a proof round and qualified for the proof mark BUT there could be many other things wrong with it that means that the military did NOT think it was serviceable and marked it DP. Mr Laidler has said time and time again that these rifles should NOT be fired. I say this because I spent a few hours earlier today reading the threads on DP / ZF / R over REME and EY marked rifles.

[browningautorifle]

DP Markings? Try this to find the thread you seek.

[Beerhunter]

Acceptance marks are made when the rifle enters military service
DP marks are made while it is in service
Proof marks are made when it leaves service

Your sequence is correct. but Proof is when it enters the civilian marked NOT when it leaves service. Not the same thing at all.

When a firearm is Proofed, it is marled as such. That is all that happens. No other marks are removed or added, unless is it a re-Proof.

BTW, what is the date of Proof? If BNP, look up the Proof Date Code.

[Peter Laidler]

But it is MILITARY proofed before it enters service. Military and commercial are boith to a similar standard but................. Oh, don't get us all going about the stupidity of it all!

[gerard488]

Please forgive me for asking questions about the " stupidity of it all"
My question should have been worded better, what I meant is If a rifle is proofed after it is "DP" stamped, doesn`t that mean it is safe? After all, isn`t that the reason for "proofing " a firearm, to prove that it is up to standards or safe?

[Peter Laidler]

IT simply means that it passed a pressure test on that day

[Alan de Enfield]

Are the proof marks military or civiliam proof marks ?

Option 1
Rifle is proof tested for military use, passes, used for many years and then having all of the necessary calibration equipment, the 'experts' decided that the 'trends' of the measurements showed that very soon the rifle would be out of specification and would become unsafe, to avoid the possibility of 'threat to life' it was down rated to DP and sold to a scrap dealer who sold it onto a country not having civilian proof tests of ex-military firearms.

Option 2
Rifle is proof tested for military use, passes, used for many years and then, having all of the necessary calibration equipment, the 'experts' decided that the 'trends' of the measurements showed that very soon the rifle would be out of specification and would become unsafe, to avoid the possibility of 'threat to life' it was down rated to DP . It was then scrapped by selling it to a scrap dealer, who decided he could make more money selling it as a 'shooter'. He had the proof-house test it and it passed.
All this shows is that it was capable of making one-more shot - who knows, the next shot, or the 100th or the 1000th shot may be the one that 'blows-up'
The proof-test (being at a higher than normal pressure) could actually exacerbate the situation and bring forward the time of 'catastrophic failure'

In the UK we have to have our cars 'tested' every three years to a Ministry Of Transport (MOT) standard - brakes, lights, seatbelts, emissions etc etc. The vehicle either passes or fails.

It could pass the test and on the way home, the exhaust could 'blow' and a bulb fail. All the test shows is that at the moment of testing it met the required specification. It makes no comment about how many more miles the car will do before the brake pads need replacing (for example)

Edit for fat finger spulling

[RobD]

Alan, do you know how stringently, at the London or Birmingham Proof House, the rifle also undergoes measuring with gauges e.g. headspace gauges?
The Birmingham proof house doesn't say much on their website http://www.gunproof.com/Proofing/proofing.html whereas the London proof house suggests gauges are used The Proof House

"At the London Proof House, proof is carried out in three steps:
•
Physical examination. The barrel and action are inspected to ensure that there are no visible signs of weakness or undue wear. The barrels are also measured and gauged to ensure that they conform to precise dimensions and tolerances.

•
Proof firing. Guns that pass examination are taken to an enclosed firing room, where they are secured in a holding device, which is aimed into a “snail” bullet catcher, a box containing a lubricated and hardened steel spiral that can safely dissipate the momentum of a bullet. The snails used at the London Proof House are safe for bullets upwards of .50 calibre. The gun is then loaded with a proof cartridge that, depending on the type of gun, will produce 25% to 50% more than the theoretical maximum service pressure. the firing chamber is closed, and the gun is fired remotely

•
Proof marks. After re-inspection and gauging, guns that pass the test, and the vast majority do, are then marked with the London proof mark. Typically, this consists of the initials GP beneath a crown, although there are special marks for unusual tests and circumstances.

[Thunderbox]

I've never heard of any Proof House comment on headspace in a full bore weapon; certainly not in any of the few hundred weapons I've submitted. I have come across quite a few rifles bearing Birmingham or London proofs that were outside headspace limits, so I assume that this is not a mandatory check. Given the things TR shooters and builders of exotic calibre weapons get up to, I'd be surprised if the Proof Houses were in a position to define all headspace conditions.


There might be a headspace check on .22"RF weapons.

---------- Post added at 05:41 PM ---------- Previous post was at 05:32 PM ----------

A

would become unsafe,

to avoid the possibility of 'threat to life'

may be the one that 'blows-up'

bring forward the time of 'catastrophic failure'

Unfortunately, this is where all the hyperbole comes in. I'm not aware of even a single documented incident of any of the above, let alone a statistical trend over millions of rifles.

There is no evidence whatsoever that rifles become dangerous simply because they have worn past a set of arbitrary gauging limits. There is not a word about this in any of the usual contemporary reference sources. If someone knows of a stack of incident reports, then lets have them here in the public domain.