Springfield Trapdoor oversize bullet

Spin a casted bullet in the mold with a drill with some lapping compound to make the mold bigger. You will have to polish out a sized to .463 or so. I would powder coat them if it was me.

The Lee "459/405HB" bullet mold usually drops bullets that are .462-.463" in diameter when using pure lead with 1 to 2% tin added to improve fill-out. If it casts a bit too small it is relatively easy to lap it a few thousandths larger as Troy Fairweather commented. Or powder coating will also add a few thousandths. Often people who are not all that familiar with casting pure or nearly pure lead alloys cast at too low a temperature to get the slugs to fill out properly and end up with under size bullets. I cast nearly pure lead projectiles at 775 to 800 degrees in a thermostatically controlled pot. Using black powder, a slightly under size soft bullet will slug up upon firing. The original "carbine" load was 55 grains of FFg black powder and a pasteboard wad (to take up the extra room in the case) and the .405 grain bullet of 50 to 1 alloy. Using smokeless powder requires your bullet be at least groove diameter or preferentially .002" over or you will get bore-leading from hot powder gasses escaping past the bullet.

.462-.463, Wow, how old is it. Was it made for paper patched bullets?

Unless you measure with a anvil micrometer it’s pretty hard to get a accurate measurement. If you accurately measured it that is a normal size. You need to get this book https://the4570book.com/ I use the Lee 405 HB mold and with a 30 to 1 lead/tin they drop at .460 to .462. My 1873 is .4615 to .462. I powder coat and size to .460 and pan lube. With 60 to 65 grains of Goex it’s hitting a 6” plate at 100 yards every shot. For my 62 year old eyes and this 137 year old Trapdoor I’m pretty happy with it.

if you have Wolf's book you'll have read that .460+ is a typical bore diameter for the original trapdoor (not the H&R replica). The oversize bore was meant to accommodate fouling. The correct bullet diameter is .459", but that's assuming you're shooting a hollow base 405 gr. bullet cast from 20:1 lead:tin alloy.

Check out the Mountain Molds website. You can select the menu in the upper left hand corner and select the nominal bullet diameter and then design your own bullet. The program is excellent and actually draws a picture of the bullet for you.
You may have to play with some of the parameters a little bit until you fully understand what each one does, but it's a lot of fun and you can get almost exactly what you want

https://www.mountainmolds.com/

Alternately, if that seems unappealing, check out the Accurate Molds catalog. You can select a pre-existing bullet from it and then specify any changes you need. The bullet that you select shows a measured drawing, so you can specify minor changes such as the diameter and any other changes that you want. There are a number of molds shown on page 19 of the catalog under the heading 46-405E or L or whatever.

http://www.accuratemolds.com/

These molds really aren't that expensive and you can buy an aluminum mold for less cost.
If your groove diameter really is .462" then a .464" bullet diameter would be needed for accuracy I would think.
If it's a soft lead bullet with black powder, then perhaps a .462" or .463" bullet would obturate and be sufficient.

soonerfan66 said:

I got Wolf's book after I bought my first Trapdoor several years ago . Lots of good stuff in it . If I could hit a 6'' target I would be pretty happy with this carbine . The rifling in both Trapdoors look pretty close and the first one I put 55 gr in it with the 405 lee bullet and it does ok but have been playing with different loads , 2f and 3f even some smokeless powder in this one and just can't seem to find a sweet spot . That why I thought about going to a larger bullet size . Don't feel bad about your eyes I am 53 and got white out on all my old rifles ( a assortment of stuff from WW2 to flintlocks ) front sight posts .

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I have purchased all of the expanders and dies that Wolf mentioned in his book from Track of the Wolf and load them how he says to. I’ve had very good luck with doing so. I don’t load the 70 grain loads as much as I do the 60 to 65 grain ones. For smokeless I use H4198 and only load at 27 grains. Those smokeless loads are not as accurate as using Goex as I don’t want to try going above 27 grains to see if higher loads would be more accurate.
That trapdoor has been in our family since before 1900 as it was my grandfathers and I don’t want to risk blowing it up.
Unless your barrel is in bad condition if you follow loading like Wolf suggests you will get it shooting well.
The reason I powder coat and pan lube for blackpowder is it took me weeks to get the lead and crap out of it and many 50 caliber brushes and I don’t want to take the chance of it getting any leading. The lands doubled in size after the cleaning and other than a very minor amount of pitting in the last 6 inches or so of the barrel it looks like it came from the factory.
I thought the barrel was clean and just worn but after I started cleaning it went from having a shine to black with craters, rusty and I really thought it was junk to what it is today.
If you go with a 500 grain bullet then you don’t have to worry about the hollow base. Read the book from Wolf it’s all in there.

soonerfan66 said:

Reeferman do you think a 500gr flat bottom based bullet shoot good in a carbine . I need to grab my book and see if Wolf says anything about that . Has anyone tried that weight in a carbine ?

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The 405 grain was used in carbines till the end of production. What expander and dies are you using?

You need to really read that book especially sections 5 and 6. I have expanders from Track of the Wolf that fit the Lee dies that will expand the case down .67”. This is very important especially using the hollow base bullet. I bought all the expanders, dies, powder compression plug and wads from them as shipping to Canada is expensive. A couple sets of Lee dies are cheap as well as the plugs for you down there. With a 2 1/2 foot drop tube I just use the bullet and wad to compress the powder up to 65 grains. The 70 grain loads I had to use the compression die.
There are others that say they don’t load the Trapdoor like Wolf lays out in his book and get better results and that may very well be true but it has worked for me. I don’t shoot more than 100 yards with it usually but can hit a 2 foot by 2 foot steel pretty much every shot at 200 yards. That’s shotgun pattern for many but dead eye Dick for me.
Not sure about yours but with my rifle at 100 yards I’m aiming about a foot lower than the target. At 200 yards at the bottom of the it.

soonerfan66 said:

I cast using pure lead at 7-800 and they come out at .460 , if I adding some tin would that help fill them out ? ..

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Yes, adding at least 2% tin to your casting alloy will improve mold fill-out providing your casting temperature is correct. With the Lee mold, keeping a good, reasonably fast casting cadence is essential to getting full-diameter bullets. If you let the mold cool down in between pours those bullets will be slightly smaller.

Also--The "hollow base" in the Lee .459/405HB does NOTHING to expand the base of the bullet upon firing. It is there to get the desired bullet profile within the correct weight and to move the center of gravity of the bullet slightly forward. Sometimes a .460/.125 card wad between powder and this bullet helps a little with accuracy.

Curator said:

Yes, adding at least 2% tin to your casting alloy will improve mold fill-out providing your casting temperature is correct. With the Lee mold, keeping a good, reasonably fast casting cadence is essential to getting full-diameter bullets. If you let the mold cool down in between pours those bullets will be slightly smaller.

Also--The "hollow base" in the Lee .459/405HB does NOTHING to expand the base of the bullet upon firing. It is there to get the desired bullet profile within the correct weight and to move the center of gravity of the bullet slightly forward. Sometimes a .460/.125 card wad between powder and this bullet helps a little with accuracy.

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There has been a lot of discussion about whether or not the Lee hollow base obturates. I’m not smart enough to be able to prove this but some who are seem to think that it does. I would think that the more lead the bullet has the better the chance of it doing so. The way Wolf explains it makes sense to me and it appears to work so that’s the best I can come up with.

soonerfan66 said:

Reeferman do you think a 500gr flat bottom based bullet shoot good in a carbine . I need to grab my book and see if Wolf says anything about that . Has anyone tried that weight in a carbine ?

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I haven't ever tried it in a Springfield Trap Door carbine, so I don't know if this is much help.
However, I own an 100+ year old Ideal tong tool in .45-70 Govt - 500, which has has a wonderful condition 500 grain military round nose bullet mold.

I once fired some factory strength smokeless reloads using this bullet through a Ruger #3 carbine and they shot well. (wheel weight alloy)
It rocked me back on my heels though.

The Ruger #3 has a rifling twist rate of 1:20"
The Springfield rifle and carbine have a rifling twist of 1:22"

This Lyman #457125 mold is very similar.

Old Stumpy said:

I haven't ever tried it in a Springfield Trap Door carbine, so I don't know if this is much help.
However, I own an 100+ year old Ideal tong tool in .45-70 Govt - 500, which has has a wonderful condition 500 grain military round nose bullet mold.

I once fired some factory strength smokeless reloads using this bullet through a Ruger #3 carbine and they shot well. (wheel weight alloy)
It rocked me back on my heels though.

The Ruger #3 has a rifling twist rate of 1:20"
The Springfield rifle and carbine have a rifling twist of 1:22"

This Lyman #457125 mold is very similar.

View attachment 864699

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You are a lucky man to have that mold. I bet it did rock you.

With pure lead or alloy softer than Wheelweight (ie:range scrap), the Lee .459” 405gr RFN will obturate.
Black powder or fast pistol/shotgun powders will obturate the slug.
I’ve had great luck with RedDot, GreenDot, Unique, and #2400 in the .45/70.

A close friend gave me the mold, along with 5gal bucket of Linotype if I’d keep him in pure lead Lee HB 405’s. It’s been a good deal. He shoots them in a .45/90 Sharps repro over Pyrodex. We’ve shot 3”groups (5-shots) at 250yds. A compressed load of Pyro, SPG LUBE in Base of bullet over a 0.30” vegetable wad, and @ magnum primer. He’s taken several deer with it too.

My Marlins like it sized .460” over 24.0gr of #2400. Shoots bug holes, as do the 405gr FN (solid base), and 30.0gr under a RCBS 300gr FNGC (318gr).

Did you ever check the crown of the barrel.