.459 Lead Bullet for .45-70

[Alonzo]

I had a nice original Trapdoor once. The groove diameter was .462. It would be well worth slugging your bore. It was hard to find a mould that dropped them large enough so I ordered a custom mould from Accurate Molds. 46-500F that drops a 500 grain bullet that can be used in either the original Trapdoor or an original Winchester 1886. You specify what size you want to size the bullet to and your alloy and he machines the mould accordingly.

This is the probably the most important observation about original trapdoors so far. I have been saying this for years and have been shooting the old originals since the mid 1970's. We found an old Lyman #457193 mold that threw a 0.463 bullet weighing 420 grains with wheel weights. This bullet has been a consistent match winner in BP cartridge matches across three provinces and Montana. The old TD was an 1889 vintage Model 1884 all original gun with the Buffington rear sight.
With the new trapdoor repros it is best to slug the bore first, as mentioned here already, then tailor your loads from there. Do not bother with chasing the extremes in bullet weights (500gr or 350gr, etc). We tried all of those weights, then returned to our old 420.
Historical note here. The Frankford arsenal loading for original 1873 to 1873/79 trapdoor was a 405 grain bullet, with 55 gr powder for the carbine and 70 for the rifle. The 500 grain did not officially come out till the early 1880's. This was after Springfield produced the experimental "Long Range Rifle" (an incredibly rare gun), which was chambered in 45-80-500 using a 500 grain bullet. The performance of this rifle and cartridge combination was of sufficient merit that Frankford experimented with using the bullet in the 45-70. It did very well and was introduced as standard for the rifle in the mid 1880's.

 

[griaguns]

The Lyman Postel .459 535 grn (depending on mix)lubed through a .459 sizing die. behind 12.5 grn of trailboss with an over powder card will be a very accurate load at 100yrds (at least it is in my 1884 ram rod Springfield)I have produced better scores in match's than most of the modern day milsurps in our monthly comp's.
(I love it when one of my 130+++ year old rifles produce better scores than the Swed's and enfields).
It thumps a bit, but man does it shoot

For the 1873 and similar I load .405 grn soft lead sized.459 with an over powder wad and 12grns of trailboss.

If the bullet is undersized you will loose accuracy after about 25 rounds due to leading.
I havnt seen an undersized U.S Springfield Trapdoor rifle and I have a few, even for the 50-70 normally sized at .512 I had a custom mold made by NEI blown out to throw a .515 boolit and this turned the rifle into a match winner from unpredictable.

 

[yonderin]

Getting to be information overload here. All I want to do is shoot my trapdoor, maybe with some handloads that approximated issue carbine loads. Maybe I should stick to factory.

Seriously, this is all pretty interesting. Thanks to all.

 

[griaguns]

Don't shoot factory rounds too much pressure

 

[yonderin]

Hmmm. I've got a couple of boxes of Remington which state safe for all rifles. Don't recall where I read it but I understood these would even be safe in a trapdoor. Guess I've been lucky so far.

Problem I noticed right away firing them was unburnt propellant in breech. Figgered that was from not enough combustion in the barrel because the ammo was produced to approximate original rifle loads and I have a carbine.

That's part of why I'm looking to handload for it.

As an aside, (if I remember right) somebody wrote of modifying cases to initiate the burn from the front end with good effect. But a lot of work involved.

 

[griaguns]

The US Springfield was not designed to shoot loads that were acceptable for Winchester and Marlins.
They were to shoot a black powder loaded round.
The pressures in more modern rounds are to hot.
If the rounds you are shooting are old the unburned powder could be due to age,when reloading and finding unburned powder simply changing to a magnum primer will solve the issue

 

[tigrr]

I'm getting ready to start reloading for an 1873 Trapdoor Carbine (repro). I haven't checked too extensively but all I can find for a 405 gr mold is .459.

From the little bit that I've found, the opinion is to load as is and fire away. Does anybody have experience that shows it's neccessary or at least a very good practice to swage the projectile while loading?

I have a good good supply of pure lead to get started so I don't see any concern in regard to higher pressures. I intend on starting with 55 gr of BP or Pyrodex RS to duplicate the issued loads for the carbine, at least to start.
Thanks for any advice.

Give it a twirl!! If you listen to all of the advice you might never get started. The mold might throw the perfect bullet for your gun who knows. You won't know till you try. If not successful then try some other advice. There is lots of recipes out there to try but you have to take the first step and shoot it.
What part of the country are you in?
Oh and I shoot my 405 gr bullet as cast. Lubed with beeswax, lard and lanolin lube.