Ken Water’s “Pet Loads” breaks down .44-40 loads into 3 categories depending on action strength, ’73s being in the “weak” category. His ’73 measured .429″ groove dia., though there can be wide variations in barrels of this period. Thing is, if you can’t find .426, what’s the alternative, if you want to keep shooting? Well, you can buy a custom mould.
These are not exactly what you want but they are in stock. Made from the old Ideal/Lyman 427098 mold. No crimping groove as it’s designed for black powder where the base of the bullet rests on top of the powder. I have used this bullet in Winchester 1873 rifles as well as Colt Frontier Six Shooter revolvers.
You could ask them if they would size to .426 inches or do it yourself.
My original 1873’s seem to like these sized to .428 inches. As Clarence suggested .429 inches might be even better for a worn bore.
https://www.buffaloarms.com/428-200-grain-rnfp-hand-cast-427098.html
I call myself a collector as it sounds better than hoarder
I was just reading a factory specification for the Model 92 & 53 in 44wcf.
It has a “Finish Bore” at .4225 with the “Depth of Groove” at .003 (X 2). So added together makes for .4285
There’s also a note “Bore Size Leading” with Min. .4225 and Max. .4235
So it looks like the factory tolerance was between .4285 and .4295 including the depth of groove of .003 x 2.
Also interesting is that they Reamed the barrels four times starting with the initial drill hole between .4125 – .4165 to get to the final bore size.
Sincerely,
Maverick
Note: I edited my post as I forgot “simple” math that the depth of groove is on both sides of the bore.
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I do not recall Winchester ever manufacturing .426″ bullets unless you are referring to Winchester’s jacketed soft point .4255″.
Regardless of manufacture bore specs, Winchester’s 44-40 bores varied between .4225″ and as large as .433″ according to original data.
It has been reported that Winchester’s factory swaged lead bullets were .427″ but I have yet to be able to confirm this. Factory dissected cartridges yielded lead bullets as small as .4245″ but that could be due to the lead being deformed by the crimping of the case neck when loaded.
In general, Winchester only manufactured .427″ Swaged lead bullets and .4255″ JSP bullets of which the manufacturing method had never changed, at least until they re-introduced the Cowboy Loads of which I measured .429″ on their swaged lead bullets.
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