Longknife
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Loc: Illinois
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I have acquired an Army Navy 12 bore SXS rifle and will need some pointers on working up a load. Thanks!
Army Navy 12 bore SXS
-------------------- Longknife
Edited by Longknife (04/01/25 08:08 AM)
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DarylS
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Now that is a nice rifle, Ed & in lovely condition. Love those fences. Do you have it in hand yet?
Seems to me I recall reading here about a forum member having the heavier SxS 12bore meant for the heavier 7 dram load, but that the case was also 3" in length. When I was shooting round balls in a SxS 12 I had, I was using a 2 3/4" plastic hull and getting the full 7 dram load in it along with bore sealing "cupped" wads. LOTSA recoil - too much recoil for the 7 1/2 pound gun I had. This looks, by the fences, to be a round ball gun. Might not be, but that is the impression I get.
W.W.Greener gives 1 round ball load for 12 bore, using a 547gr. ball. The calibre of that gun is listed as .725" with 110gr.(4 drams) "powder" for a 7 1/2 pound gun & producing 1,384fps.
A different load of 7 drams, ie: 191gr. "powder" and 599gr. projectile (I assume short conical) with gun weight of 13 pounds & producing 1,584fps.
The cross section of an 8 bore round ball load, shows powder, then a thin card wad, then thicker fiber wad and another thin cupped upper surface to hold the ball, then the case crimped into the ball.
OH- do I see NP on the bottom of the barrels? Appears so. If so, then Lyman Shotshell manuals give 12 bore data for round balls as well as conicals up to 525 or so grain weight.
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fjrdoc
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Beautiful SxS.
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lancaster
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yes








-------------------- Norwegian hunter misses moose, shoots man on toilet
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bringing civilisation to the barbarians
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Huvius
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Loc: Colorado
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The more I look, the more I like it!! What a rifle!
-------------------- He who lives in the past is doomed to enjoy it.
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85lc
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Loc: Georgia, USA
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That is a very nice 12 bore double rifle. I like the tasteful engraving. That looks liked a fun rifle to shoot and just look at/handle.
-------------------- RB
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DarylS
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I just noticed the weight, missed it before. Intermediate weight from between the light 4 dram load & 7 dram load. The 5 dram load was also used. Thought that was also in Greener's book, but couldn't find it right away. 5 drams = 136.5gr.
-------------------- Daryl
"a gun without hammers is like a Spaniel without ears" King George V
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NitroX
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Nice 12-bore rifle. I think a 12-bore makes a nice versatile bore double rifle.
-------------------- John aka NitroX
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Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
"A Sharp spear needs no polish"
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DarylS
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Same here, John. The round ball is large enough and heavy enough to be useful for a wide range of game, if not shooting conicals, light or heavy.
-------------------- Daryl
"a gun without hammers is like a Spaniel without ears" King George V
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CM76
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Loc: Wollongong, NSW Australia
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Lovely A&N 12 bore rifle. Congratulations!
Chris
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Longknife
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I just got back to this jewel after plowing and shoveling snow for two days! The bores are of a slightly different size as it says in the description. I used my digital caliper to come up with the groove depth. The ball, or bullet size is going to be an 11 bore.
R 18.9 mm--.744--gr .754 L 18.8 mm--.740--gr .750
A .754 groove dia pure lead ball weighs 643 gr. (calculated). Accurate molds make several different style of bullet molds starting with the 74-700 at about 700 grains that you can tweak (enlarge) up to .015. There are other changes you can make too. So do I go with a round ball, or a bullet, and what size? Thanks, ED
https://accuratemolds.com/catalog.php?page=33#catalog-anchor
Edited by Longknife (07/01/25 10:37 AM)
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3DogMike
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Ball or bullet will somewhat depend upon the rifling twist. I have three 12 bore rifles and one has a 1:96 (slow) twist while the other two have a 1:52 twist. The slow twist one for sure likes round ball loads. The faster twist rifles do fine with a conical from Accurate Molds or a round ball.
Personally I’d get either ball or bullet sized at .750 and be happy. With soft(ish) bullets they will bump up to fit the bore and you have nice deep rifling to grip the projectile as well Do your ball or bullet from 1-40 to 1-20 tin/lead, they cast much nicer than pure lead.
You will need to figure out if your rifle is a brass case or paper case chamber. With your groove diameter I would guess brass case. You would know which right away if a ball in a paper case wont chamber (thicker case mouth). If you go with brass cases I’d suggest avoiding the cases from Track of the Wolf. The turned brass have a sharp 90° junction at the web and fail very quickly at bore rifle pressures due to the stress point.
Have fun, Mike
-------------------- "Will Rogers never met a fighter pilot"
- Anon
“Always carry a flask of whiskey in case of snakebite, and furthermore always carry a small snake."
-- W. C. Fields
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DarylS
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What about mag-tec brass from Buffalo Arms? I think it might only be 2 5/8" long, though. Next step, Ed, is to find the rate of twist.
-------------------- Daryl
"a gun without hammers is like a Spaniel without ears" King George V
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93x64mm
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Longknife, you have one pretty little piece there indeed! Love the exquisite engraving, just beautiful in my eyes. Hope you get it going soon before it gets too cold over your side of the pond. Will be interesting to see how you go with such a variation in groove/bore sizes, hopefully one load will be a stand out for you! Lucky bugger!
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Longknife
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Loc: Illinois
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Thanks for all the kind words, she sure is a beauty!!!!
Daryl and 3 Dog, thanks for the loading info. I did measure the twist, just forgot to list it, somewhere around 1-44. A faster twist for shure in a bore rifle, and it should shoot conical bullets fine. I put a steel .750 slug into a plastic case and it was a slip fit, but it chambered fine, I don't have any paper to try. I think I will order an AM 73-700 mold and have it enlarged to .750. I also have some Mag-Tech brass that takes small pistol primers and some G FIOCCHI marked (Italian) brass, that takes shotgun primers. They both mic about .770 inside. I have a lot of pure lead ingots and a lot of WW ingots, will the ww work sufficiently. I hear the BN is about 12.5 and can be raised to 23 or so by dropping them in water? any thoughts? ....Ed
Edited by Longknife (09/01/25 04:00 AM)
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DarylS
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Water dropping the alloys from the mould will make them too hard. It takes about 12 hours for maximum hardness to be reached, then over time of years, they will slowly soften back to the original WW alloy's brinel. Due to the slightly differing temperatures when they hit the water, the brinel reached will normally be from about brinel 25 to 32 or 33 max. This is way too hard. The trick is going to be to use a bullet soft enough to obturate, but hard enough to 'take' the rifling. I would suggest a mix of 50:50, pure lead and your WW alloy to get a brinel around 8. This alloy worked VERY well in my .50 Alaskan with 550gr. bullets. They were very accurate and "took" the 24" ROT very well. Straight WW alloy is likely too hard to obturate. This would suggest an even softer alloy, likely to pure lead would also work in your 12 bore. Paper cases might be too thick in the 'neck'. Most compression formed plastic cases are VERY thin in the neck. The cheaper plastics, are thicker.
-------------------- Daryl
"a gun without hammers is like a Spaniel without ears" King George V
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degoins
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Wowie!!
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