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Thread: Nitro in a BP revolver.

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    Nitro in a BP revolver.

    A friend of mine has obtained some nipple replacements which with small modification to the hammer allow the use of shotgun primers in his .45 Cattleman repro . He has been told that he can put up to 3 grains of nitro in it, which he has been using with no ill effects (so far). The gun is clearly marked "BP only". It has not been re-proofed for nitro.

    Unfortunately he has now obtained a Chrono and is finding MV to be far too low with ball and (naturally) even lower with the much heavier bullets he has started casting. He wants to up the load. I have expressed some concerns at this (both the starting point and his ambitions to up the load) since I believe that the pressure curve with nitro is much shorter and steeper than with BP.


    Anyone admit to doing this?

    Anyone know what BP vs nitro proof load pressures are?

    Short of re-proofing it is there any way to safely explore this whole idea?

    How can you determine if safe limits are being reached?

    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?

    He is shooting on land he owns and AFAIK there is no legality problem with this.
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    Quote Originally Posted by Turnup View Post
    A friend of mine has obtained some nipple replacements which with small modification to the hammer allow the use of shotgun primers in his .45 Cattleman repro . He has been told that he can put up to 3 grains of nitro in it, which he has been using with no ill effects (so far). The gun is clearly marked "BP only". It has not been re-proofed for nitro.

    Unfortunately he has now obtained a Chrono and is finding MV to be far too low with ball and (naturally) even lower with the much heavier bullets he has started casting. He wants to up the load. I have expressed some concerns at this (both the starting point and his ambitions to up the load) since I believe that the pressure curve with nitro is much shorter and steeper than with BP.


    Anyone admit to doing this?

    Anyone know what BP vs nitro proof load pressures are?

    Short of re-proofing it is there any way to safely explore this whole idea?

    How can you determine if safe limits are being reached?

    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?

    He is shooting on land he owns and AFAIK there is no legality problem with this.
    There is one VERY good reason why BP loads and nitro loads are not usually interchangeable. The material from which BP handguns are made is NOT of the same grade as that used to make nitro-firing guns. The elastic limits of a cylinder designed for 18-20 kpsi maximum are reached much quicker when you are shooting loads with pressures double that.

    Your friend might find that out the hard way.

    He can do what he likes on his own land. So long as he has someone who'll know where he is to go look for him.

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    as tac says bp only.
    i would like to know how strong the pietta bp pistols are though as they supposed to be made of modern steel etc.
    just to make sure.......i am only curious and would never use smokeless in any bp pistol.
    on a side note......uberti make nice .44 russian revolvers that use smokeless loads....are these made of different steel ?

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    Quote Originally Posted by loiner1965 View Post
    as tac says bp only.
    i would like to know how strong the pietta bp pistols are though as they supposed to be made of modern steel etc.
    just to make sure.......i am only curious and would never use smokeless in any bp pistol.
    on a side note......uberti make nice .44 russian revolvers that use smokeless loads....are these made of different steel ?
    Must be so. Although the original was a BP load. Remember that over in the US the Ruger Old Army has a following of people who regularly swap out the BP cylinder for a .45 lead bullet only Long Colt cartridge-firing version. You'll recall that ALL ROAs are made of high-grade stainless steel in any case. But even so, the Nitro cylinder is entirely a new one and must have different heat treatment to increase its mechanical performance.

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    I would not use nitro in a BP revolver, or any BP gun.
    I don't think the steel is good enough to stand the higher pressures. I suspect that many reproductions use the minimum grade steel and are case hardened to reduce wear.
    The quality of the steel on originals, locks, triggers etc. is harder than modern reproductions. And the steel on some original barrels seems better too.

    I have not tested the hardness of the metal but how a file or oil stone cuts the surface is a fairly good guide.

    The priming compound in a shotgun primer is probably 2-3 times more than an ordinary N0.11 cap. That extra brissance from the shotgun primer will help to increase the pressures with the nitro. It is like using a magnum primer!

    He should try the shotgun primers with BP and work a load up.

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    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

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    Quote Originally Posted by enfield2band View Post
    He should try the shotgun primers with BP and work a load up.
    Quite. The rest of your post is therefore unnecessary - you've said ALL that is needed.

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    Quote Originally Posted by sclg View Post
    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.

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    Thank you gentlemen. You have confirmed my concerns, particularly that there is no way to know when limits are being approached.
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    Quote Originally Posted by tacfoley View Post
    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

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    It's a no no!

    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.
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    Quote Originally Posted by Turnup View Post
    [/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.
    Last edited by tacfoley; 08-04-2020 at 08:20 PM.

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    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?!

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    Quote Originally Posted by springfieldm6 View Post
    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

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    Quote Originally Posted by tacfoley View Post
    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.

    Quote Originally Posted by tacfoley View Post
    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.
    True freedom includes the freedom to make mistakes or do foolish things and bear the consequences.
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