Proofing

Sparks

Tackleberrywho wrote: »

The real accuracy of a rifle is not tested until after 50 metres.

That's just plain wrong Tack.

Several rifles can 1 hole @50 metres

Yeah, but they have to make larger holes with far more kinetic energy behind the round than demonloop's do in order to hold that 1 hole group...

Honestly, you can't compare demonloop's bleiker to your .223; in any fair, accuracy-based metric, you'll lose. They don't cost five grand and up per rifle just for the nametag...

rowa

The comparison i drew between things like hydraulic hoses and steam boilers and the barrels of firearms was merely to illustrate that a lot of common everyday products are pressure tested. The method of their testing (explosive or a slowly applied load) is in keeping with how they operate.

As for metallurgy , even a 10% overload would still be in the barrels steel elastic region on the stress-strain curve , as the name suggests the steel behaves in an elastic manner and returns to its original shape , if it doesn't the steel has passed into the plastic region and is unsafe. Sparks the possibility of using x-rays or ultrasound on boilers doesn't mean the pressure test (hydraulic or up to pressure under steam) is not done, it is merely an extra line of testing. I used to be involved in that game , not anymore.

The government repeeling the proof act was done at a time when there was no firearms
manufacturing being done in ireland anymore and any new gun sold here came in from abroad
and was tested abroad, the new custom rifle builders have exposed the lack of independent
testing of newly made irish rifles.

Its not just the uk tackleberry that have those laws , but practically every member of the
european union and the likes of russia and saudi arabia amongst others.

http://en.wikipedia.org/wiki/Commission_Internationale_Permanente_pour_l'Epreuve_des_Armes_à_Feu_Portatives

Tackleberrywho

Sparks wrote: »

That's just plain wrong Tack.

Yeah, but they have to make larger holes with far more kinetic energy behind the round than demonloop's do in order to hold that 1 hole group...

Honestly, you can't compare demonloop's bleiker to your .223; in any fair, accuracy-based metric, you'll lose. They don't cost five grand and up per rifle just for the nametag...

Thats where you and I will differ on opinion.
I have a vernier calipers that says I can put 10 rounds into a smaller hole than 7mm....

When your €5k .224 calibre rifle can shoot under an inch at 200 yards I'll take my hat off.
Your right in one thing, you can't compare a .22lr with a .223 Custom Rifle that stands me ~€2.5K before I scoped it.

It's like comparing high quality go-carts with F1 cars

Sparks

rowa wrote: »

As for metallurgy , even a 10% overload would still be in the barrels steel elastic region on the stress-strain curve

It's supposed to be. But hell, if you can go by what it's supposed to be rowa, you wouldn't need to test in the first place. That's why I mentioned the sioux city crash above - that was caused by a turbine blade that passed all surface inspection tests, failing catastrophically (explosively in fact) because of a flaw in the metal in the interior of the blade. If such a flaw existed in the steel of your barrel, you could look at it all day and not see it; and proofing wouldn't be guaranteed to spot it, because it takes time for the flaw to develop; one proofing shot might not necessarily cause it to let go.

Sparks the possibility of using x-rays or ultrasound on boilers doesn't mean the pressure test (hydraulic or up to pressure under steam) is not done, it is merely an extra line of testing. I used to be involved in that game , not anymore.

Yup, not saying the pressure test wouldn't be done; I'm just saying that proofed doesn't necessarily mean safe; it just means proofed. More than one way for a barrel to fail, and proofing doesn't check them all.

demonloop

Tackleberrywho wrote: »

With the greatest of respect, a .22lr and a centrefire rifle SAAMI pressures are chalk and cheese.

Over-pressure is over-pressure though.

Tackleberrywho wrote: »

Did you ever consider your Lilja may do 6mm groups had it not been proofed .

No, because I have the test group from BEFORE it was proofed too. Its 12mm.

Tackleberrywho wrote: »

The real accuracy of a rifle is not tested until after 50 metres.

Damn, Sparks beat me to it...

Tackleberrywho wrote: »

Several rifles can 1 hole @50 metres, infact my .223 can shoot consistently better groups than your Lilja at the same distance. Should I get that proofed to prove otherwise?

Any measured groups you can post on here? I have loads...

Tackleberrywho wrote: »

Custom centrefires are 600-1200 yard Rifles depending on calibre, things only get tricky after 50m;)

I shoot with my elbows 1m behind the line so must be just as tricky then?

Tackleberrywho

rowa wrote: »

The comparison i drew between things like hydraulic hoses and steam boilers and the barrels of firearms was merely to illustrate that a lot of common everyday products are pressure tested. The method of their testing (explosive or a slowly applied load) is in keeping with how they operate.

As for metallurgy , even a 10% overload would still be in the barrels steel elastic region on the stress-strain curve , as the name suggests the steel behaves in an elastic manner and returns to its original shape , if it doesn't the steel has passed into the plastic region and is unsafe. Sparks the possibility of using x-rays or ultrasound on boilers doesn't mean the pressure test (hydraulic or up to pressure under steam) is not done, it is merely an extra line of testing. I used to be involved in that game , not anymore.

A youngs modulus, I can hear my college lectures still ....

.243

Tackleberrywho wrote: »

All proofing does is takes the good out of custom polished barrels,

wrong !!! all proofing does is to make sure the guns chamber can pass a pressure test for firing ammunition safely,
it basically means that it can be safe to use,
can you explain how one "hot load" fired in a chamber effects accuracy

It wasn't me!

Does anyone really believe a barrel is less accurate as a result of having been proofed? If so, I'd love to hear the rationale.

demonloop

It wasn't me! wrote: »

Does anyone really believe a barrel is less accurate as a result of having been proofed? If so, I'd love to hear the rationale.

It seems some do. Hard to prove either way though.

It wasn't me!

demonloop wrote: »

It seems some do. Hard to prove either way though.

Personally I think it's bollocks, and there's certainly no useful rationale behind it. I don't think proofing is particularly useful or necessary, but there's nothing wrong with it either. It's not a bad thing.

Sparks

Mod note: Split out the .22lr-v-.223 stuff to its own thread.

Tackleberrywho

demonloop wrote: »

It seems some do. Hard to prove either way though.

In my experience, the things that shave mm off groups are small and subtle.
The crown, the machining of the rifling, the chamber, the trigger break setting pressure. (the ammo :eek:)

I have tweaked with all of these over the past couple of years.
when shooting under 1/2" @100 from baseline, getting the groups smaller is harder and harder the tighter the groups go.

So just when you find that sweet spot, go in excess of your SAAMI approved powder charge and try to detune or Burst.:eek:

would you buy a Ferrari and pay someone to leave it on the rev limiter for an hour?

.243

Tackleberrywho wrote: »

In my experience, the things that shave mm off groups are small and subtle.
The crown, the machining of the rifling, the chamber, the trigger break setting pressure. (the ammo :eek:)

I have tweaked with all of these over the past couple of years.

So just when you find that sweet spot, go in excess of your SAAMI approved powder charge and try to detune or Burst.:eek:

in what way have you "tweeked" the chamber to make your gun shoot better???

unless you are reloading the above quote is void,and if you are reloading and go beyond the max powder charge (which is one of the golden rules of reloading that you should never do)and blow your gun,you shouldnt deserve a gun,
oh and you also dont have to go to the max powder charge to blow a chamber there is another factor that will cause it,
its called excessive pressure,