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Had a successful day shooting the MH for the first time. Thanks to everyone who gave input regarding the MH and it's ammo. This is not only my first and only MH but also my first attempt at making up BP cartridges. I would like to work up a more gentle load though. I only used 80g of F and it still punished my shoulder. The attached video shows a steel silhouette at 400 yards.
- New2Enfields

 

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I think the British developed a carbine load with 55 grains of BP (interestingly, at least to me, the US also developed a carbine load for the Trapdoor when the regular 70 grain charge was too punishing - it was also 55 grains of propellant). Not sure what or how much filler was used, but expect there was some to compensate for the 30 grain reduction in charge.

As to the 18 grains of Green Dot - I'd be interested in that as well. I expect a bit of kapok fiber would work to keep the charge back next to the primer, but that would be speculation on my part. Seems like green Dot goes off pretty readily, so could be no filer required. Hope we hear soon from Iron Brigade.
 

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The first step in developing a smokeless powder load in the 577/450 Martini is finding solid head cases. Do not use the balloon head CBC cases for smokeless powder. The way pressures generates in a smokeless powder load is much different than in a black powder load. Find some Kynoch or Bertram solid head cases. The CBC case is a semi balloon head case. It i s not designed or intended for smokeless powder.

Fast burning shot gun powders are not good choices for smokeless loads in large volume cases. They can be used but you need to study and understand the Vielle effect before you start loading. George Burrard in his book The Modern Shotgun has a translation Vielle's work. Dell and Schwartz cover these reduced load and describe the there testing of the Vielle effect in their book, the Modern Schuetzen Rifle.



A much better reference for loading smokeless powder in large black powder cartridges is Greame Wrights Loading for the British Double Rifle. This book includes actual pressure testing of loads developed with smokeless powder in black powder cartridges. The loads are developed to duplicate the original black powder pressures with smokeless powder. This allows the double rifle shooter to have a smokeless powder load that regulates in the old doubles, but does not strain these old guns that were designed and built to work at lower pressures. Nitro for Black loading (NfB)is discussed.


If you do not understand or can not comprehend the Vielle Effect, you should not attempt loading smokeless charges in a Martini Case!

If you do not understand NfB loading parameters, you should not attempt loading smokeless charges in a Martini Case!
 

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The first step in developing a smokeless powder load in the 577/450 Martini is finding solid head cases. Do not use the balloon head CBC cases for smokeless powder. The way pressures generates in a smokeless powder load is much different than in a black powder load. Find some Kynoch or Bertram solid head cases. The CBC case is a semi balloon head case. It i s not designed or intended for smokeless powder.

Fast burning shot gun powders are not good choices for smokeless loads in large volume cases. They can be used but you need to study and understand the Vielle effect before you start loading. George Burrard in his book The Modern Shotgun has a translation Vielle's work. Dell and Schwartz cover these reduced load and describe the there testing of the Vielle effect in their book, the Modern Schuetzen Rifle.



A much better reference for loading smokeless powder in large black powder cartridges is Greame Wrights Loading for the British Double Rifle. This book includes actual pressure testing of loads developed with smokeless powder in black powder cartridges. The loads are developed to duplicate the original black powder pressures with smokeless powder. This allows the double rifle shooter to have a smokeless powder load that regulates in the old doubles, but does not strain these old guns that were designed and built to work at lower pressures. Nitro for Black loading (NfB)is discussed.


If you do not understand or can not comprehend the Vielle Effect, you should not attempt loading smokeless charges in a Martini Case!

If you do not understand NfB loading parameters, you should not attempt loading smokeless charges in a Martini Case!
Am not sure I want to track through those equations. Been too long since I did that sort of math, and I have my suspicions as to whether I could get it right, thus leading to disaster. Better I should, instead of trying to develop loads, cook-book them from somebody else who experimented nd got there without breaking his gun.
 

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The British seemed to do OK with cordite loads.I have been firing smokeless in 577/450 for fifty years now,and have found a few things.My "thin" CBC cases have over a hundred smokeless reloads on them.As a pressure indicator,these "thin" cases take some twenty reloads before they fireform to the chamber.I use light loads,never exceeding 26gr of smokeless .In the early days,Ballistite was the best powder,never requiring filler or wads.I then tried many kinds of shotgun powder,all needed wads over powder to eliminate hangfires.Then ,when Trailboss hit the market,it was the ideal powder,easy to light,no wads or filler needed.But "experts" say it produced high peak pressures,but I have never seen any evidence .I have now settled on a duplex load of 13gr of TB and 13gr of other,its the most accurate smokeless load I have ever tried,and many other shooters use it too.No filler or wads,I shake the case a little before firing.This is not a recommendation,you must work some things out for youself.
 

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Nice shooting, what bullet did did you use? I have also found that I am taking my Martini to the range less and less due to the excessive recoil by full house loads. Even with a shoulder pad, 20 rounds is all I can do. I usually take 40 with me and the last 10 or so aren't fun at all and I shoot them just do shoot them.

I have experimented with 36 grains of H4198 and a cotton filler but am getting hang fires. Switching to magnum pistol primers and possibly a light crimp on the bullet should fix that but I haven't had a lot of free time. A light charge of Unique (14 grains) has worked well with no ignition issues (no filler needed) but it's a 100 yard plinker load, powder burns too quickly to give the needed velocity for much past that distance. But I have 15 pounds of the stuff so.......don't want to turn this into a smokeless martini thread....

I've used the X Ring parallel sided PP mould with great results as well as the regular .468 grease groove mould. My next batch is using Lee .457 bullets I casted and patched up to .468. They should shoot well.
 

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US also developed a carbine load for the Trapdoor when the regular 70 grain charge was too punishing - it was also 55 grains of propellant). Not sure what or how much filler was used, but expect there was some to compensate for the 30 grain reduction in charge.

QUOTE]

The 45 Gov (45/70) Carbine load used a cardboard tube that reduced the volume of the case. Some of the case from The Little Big Horn Battle field were found in the 1990s with the tube still intact. Worst for wear but there.
 

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US also developed a carbine load for the Trapdoor when the regular 70 grain charge was too punishing - it was also 55 grains of propellant). Not sure what or how much filler was used, but expect there was some to compensate for the 30 grain reduction in charge.

QUOTE]

The 45 Gov (45/70) Carbine load used a cardboard tube that reduced the volume of the case. Some of the case from The Little Big Horn Battle field were found in the 1990s with the tube still intact. Worst for wear but there.
Thanks for that information, Dan. I've read the report done by Fox et al after the big fire, and it included discussion of cases, but concentrated on identifying whether any came from the same guns (and yes, some did). Don't recall anything about filler tubes. Meaning just that - don't recall. I see no reason that wouldn't work, and much easier in a straight-case than the bottle-necked 577-450.
 
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