Nitro in a BP revolver.

[sclg]

Short of re-proofing it is there any way to safely explore this whole idea?
Not unless you are attracted to the idea of possible maiming.

How can you determine if safe limits are being reached?
It's safe until it isn't.

Would it be feasible to assume that if MVs are kept within reason (he wants to get to 750fps) then peak pressures are not excessive?
No!
Standard ballistics curves show you the chamber pressure against distance travelled down the barrel. The area under that curve is the bullet velocity. Hence if you want more velocity you need a longer barrel or a higher chamber pressure. The problem is that a) he has no idea what peak pressure he's generating and b) he has no idea what peak pressure is excessive.

There are far too many unknowns.
S

[tacfoley]

Short of re-proofing it is there any way to safely explore this whole idea?
Not unless you are attracted to the idea of possible maiming.

How can you determine if safe limits are being reached?
It's safe until it isn't.

Would it be feasible to assume that if MVs are kept within reason (he wants to get to 750fps) then peak pressures are not excessive?
No!
Standard ballistics curves show you the chamber pressure against distance travelled down the barrel. The area under that curve is the bullet velocity. Hence if you want more velocity you need a longer barrel or a higher chamber pressure. The problem is that a) he has no idea what peak pressure he's generating and b) he has no idea what peak pressure is excessive.

There are far too many unknowns.
S

You can take it to the bank that NEITHER UK Proof House would proof-test-fire a BP handgun for ANY nitro load. Apart from the fact that it would be illegal, that is.

A firearm made for a nitro load is deemed fit for use with BP - indeed, many replicas of rifles can shoot both types of cartridge safely - Trapdoor Springfields [with lead only], Sharps, Smith, Rolling blocks, High Walls et al, ALL with lead projectiles, but not the other way around.

[Turnup]

Thank you gentlemen. You have confirmed my concerns, particularly that there is no way to know when limits are being approached.

[Turnup]

You can take it to the bank that NEITHER UK Proof House would proof-test-fire a BP handgun for ANY nitro load. Apart from the fact that it would be illegal, that is.

A firearm made for a nitro load is deemed fit for use with BP - indeed, many replicas of rifles can shoot both types of cartridge safely - Trapdoor Springfields [with lead only], Sharps, Smith, Rolling blocks, High Walls et al, ALL with lead projectiles, but not the other way around.

tac, can you support these two claims? Seems to me that nitro proof testing a gun which already has BP proof marks is no more risk than nitro proof testing a gun which has no proof marks. And exactly what law is broken here? Just trying to learn.

Completely understood

[lilguy43uk]

Some time ago I posted pictures on here of a BP revolver that one of our club members loaded with nitro. I can't remember all the exact details but he saw the word "universal" on the powder bottle and assumed it would be OK in all guns.

It was very lucky that nobody got hurt when the cylinder blew out. The divisions between the firing points took most of the force but someone stood behind him caught a small piece of shrapnel in the face. Fortunately it didn't do any permanent damage.

As a result, anyone home loading now has to pass a short course and submit loads for evaluation.

[tacfoley]

[/COLOR]

tac, can you support these two claims? Seems to me that nitro proof testing a gun which already has BP proof marks is no more risk than nitro proof testing a gun which has no proof marks. And exactly what law is broken here? Just trying to learn.

Completely understood

Be my guest, and take your BP proofed gun to London or Birmingham and ask for it to be proofed for nitro. The law is the CIP regulations, which are NOT advisory, but compulsory in those countries that have signed up to them. The UK is one such country and the rules are called the Proof Acts, which make them into law.

I'll just say it again - if your .44cal under-lever rifle or carbine has been proofed for nitro, as most, if not all, modern production are, then it will be safe to use the equivalent BP load.

But if your original .44cal under-lever rifle or carbine was proofed for a BP load, then it would be extremely unlikely to survive the nitro-proof load, typically 1.25 - 1.5 times the maximum load for a NITRO firearm. The words 'black powder only' on a firearm are not there for fun.

[springfieldm6]

I don’t believe there is any legislation which specifically prohibits you from sending your blackpowder proofed revolver to the proof house to be reproofed to nitro - many have had firearms reproofed from blackpowder to nitro. HOWEVER the proofmaster may not accept a firearm for proofing if he considers that it will put him and his assistants in “unusual danger”. The consequences of using nitro in firearms intended for blackpowder are well documented. I believe that the revolver cylinders made by the likes of Westlake and Anvil for nitro loads are specially made for nitro, rather than modified blackpowder proofed cylinders, and I do not doubt that they would have exercised, and have been able to demonstrate, diligence to the proof master prior to submission for testing. Personally I would not risk using nitro in a blackpowder revolver - i value my hands, face, friends, etc too much. I’d also question how your friend has managed to get authorisation to use the revolver on his own land - vermin control?!

[sclg]

I’d also question how your friend has managed to get authorisation to use the revolver on his own land - vermin control?!

That's a very good point. I can't see the police ever giving authorisation for a BP pistol other than for 'target shooting' which means an 'authorised range' condition would apply. i.e. a range with a formal risk assessment and full insurance cover.

S

[Turnup]

[QUOTE=springfieldm6;7845586 I’d also question how your friend has managed to get authorisation to use the revolver on his own land - vermin control?![/QUOTE]

That's a very good point. I can't see the police ever giving authorisation for a BP pistol other than for 'target shooting' which means an 'authorised range' condition would apply. i.e. a range with a formal risk assessment and full insurance cover.

This has little to do with my post but trust me on this - in respect of firearms law it's all legit (never quite understand why folk instantly jump to other conclusions). He has an appropriate range on his own land. He has vermin control on his own land. He has Humane Dispatch with no limitations on location. I will not go into further detail as this might identify him but there are good reasons for this endeavour.

[Turnup]

Be my guest, and take your BP proofed gun to London or Birmingham and ask for it to be proofed for nitro.

Not my gun and like you I want nothing to do with the whole idea - trying to keep my friend in one piece.

The law is the CIP regulations, which are NOT advisory, but compulsory in those countries that have signed up to them. The UK is one such country and the rules are called the Proof Acts, which make them into law.

That is no answer to the question "What makes it illegal to submit a BP proofed gun for nitro proofing" You have asserted that to do so is illegal and when asked for support you in effect have simply repeated "It is against the law (CIP and Proof Acts). There is no such provision in either of them. Neither is there any particular law against owning or shooting a gun which is not proofed, or is out of proof or in loading it with more than the proofed load. The law prohibits only the sale of such an item.

[tacfoley]

Not my gun and like you I want nothing to do with the whole idea - trying to keep my friend in one piece.

That is no answer to the question "What makes it illegal to submit a BP proofed gun for nitro proofing" You have asserted that to do so is illegal and when asked for support you in effect have simply repeated "It is against the law (CIP and Proof Acts). There is no such provision in either of them. Neither is there any particular law against owning or shooting a gun which is not proofed, or is out of proof or in loading it with more than the proofed load. The law prohibits only the sale of such an item.

Sir, since you clearly know far more about the Firearms and Proof Acts in this county than I do, particularly with regard to requesting that a gun made explicitly for BP propellant be retested to see if it will withstand the rigours of shooting a nitro load, I hand the thread over to you.

As noted above, Mr Westlake's cylinder are made to shoot nitro loads, as, indeed, are the cylinders used to convert the ROA to shooting nitro cartridge loads. AFAIK, and I'm sure that you can correct me here, of all the countries on the planet where BP firearms are legal, only 3/4 of the UK has this ridiculous loose-nitro muzzle-loading revolver requirement.

[pothunter]

You can take it to the bank that NEITHER UK Proof House would proof-test-fire a BP handgun for ANY nitro load. Apart from the fact that it would be illegal, that is.

A firearm made for a nitro load is deemed fit for use with BP - indeed, many replicas of rifles can shoot both types of cartridge safely - Trapdoor Springfields [with lead only], Sharps, Smith, Rolling blocks, High Walls et al, ALL with lead projectiles, but not the other way around.

Why would it be illegal for the proof house to carry out what is effectively a pressure test on a BP firearm with nitro, when the reason for its existence is to pressure test firearms to ensure that they are safe??
Before submitting it to a proof charge the firearms are inspected to indicate as to whether they are safe to test and can be rejected at that point.
Rather than individuals submitting firearms for proof or reproof it is normally done by a maker of smith who has already carried out any work required prior to submission.

This is the link to Birmingham, Linky

[harrysmith]

I always assumed that it would be the complete firearm that is proof tested. So, if a BP pistol is converted to nitro is only the cylinder tested? Doesn't this mean that the only part of the firearm that is nitro capable is the cylinder? Or is that the only part that needs to be.

[simgre]

I had a nitro converted revolver years ago when they first began to emerge. First point, as with your friend, I chrono’d mine and was also surprised at the very low velocity. It was a .36 cal and with ball gave an average of 565fps! That’s a ME of just over 50ft/lbs! But, I lived with it as the ES was very, very low and this consistency equates to very nice groups at 25yds!

Secondly, the proof marks were displayed on the barrel, frame and cylinder and on the barrel was etched something like; (3.0gns Herco. #209) with a proof mark after it. That was the load and primer it had been proofed for.

[vbull]

As most of you guys know, there are several companies in the US that manufacture nitro conversions for most BP revolvers. The frame and barrel of a BP revolver will apparently take the extra stresses of nitro but the cylinder will not which is why these conversions are basically a stronger cylinder and separate back plate which holds the shotgun primers. If you look at the cylinder walls on say a 44 BP revolver and compare to a 44 nitro revolver cylinder you will see the BP cylinder walls at the front are thinner. Edited in: Just to clarify, the back plate I referred to above DOES NOT take shotgun primers, they have five or six firing pins depending on which model of conversion you go for. These conversions I'm talking about allow the use of metallic cartridges. Sorry if I caused a bit of confusion there, I think the lockdown is getting to me...