1873 trapdoor keyholing with 45-70 MB 405 grn bufallo .459 diam bullet

[bassin57]

Hi,
I am a new member and a friend recommended this web site for boolit casting. I have a problem using the 45-70 Missouri bullet (405 grn FB .459 brinell hardness of 18) in my 1873 trapdoor. I think the bore diameter is too large for this bullet. I have purchased a Lee mold from Track of the Wolf. Its a 405 grn hollow base bullet with a diam of .459 I plan on casting with a softer alloy. What alloy hardness would allow this bullet to expand and seal the bore? I have set aside some soft clip on wheel weights and some tin for this project. Also after reading a post on this web site regarding powder coating I gave it a try on the cast MB I had purchased. After powder coating the bullet diameter increased to .462- .463. I have used powder coated bullets in my handgun with success but in a an original 1873 45-70 will I have pressure problems ...I load my bullets at 1200 fps with smokeless. I have considered slugging the bore but am afraid of damaging the rifle. Any suggestions from forum members would be appreciated.
Bassin57

[Larry Gibson]

I shoot lots of the Lee 459-405-HBs in TDs. At 1200 fps I suggest a 1-20 tin - lead alloy. I also suggest leaving the bullets "as cast" and not sizing them to .459. You can hand lube them, TL them or pan lube them all of which can work fine. My Lee mould drops them at .463 with 1 - 20 alloy and they shoot extremely well in original TDs.

Larry Gibson

[dh2]

I have this project going too with my trap door I cast the lee 405 gr HB mold with stick on wheel weights trying to get close to pure lead I am pushing it with IMR4198 , I need to get it to the range I hope it will improvement over the RCBS 45-405 FP .

[masscaster]

I have everyone I know shooting a Lyman #457483 - GC boolit. I also shoot this in mine. It is the GC version of the Lyman #457124.
Lyman list the boolit @ 378 grs. Lyman #2, but I use 30 lbs. COWW & 20 lbs. PB with a little solder/tin fluxed in. Water quenched and sized to .458. White Label 2500+ is the lube w/ Gator Checks. Comes out at around 400 grs. when done.
With Smokeless it is very accurate out to 150 yards, perhaps more but I don't go past that.

NOE had a GB on this boolit as clone listed as NOE - 462483 ( I got a 4 Cav.). ; )
One person does prefer it sized to .459.

Jeff

[ascast]

what larry g said, also big and soft if that does not work, look long and hard at the muzzle. These guns were cleaned from the front. It is not un-common to find the rifling has been scrubbed away in the first inch or so. Its worth taking a good look at.

[country gent]

Try slugging your bore to find out what size it actually is. .459 is probably small and at 18 bhn not slugging up to fit seal the bore properly. 20-1 is popular as is 16-1, 30-1 and 40-1. Some evan use pure lead. You need a bullet that will bump up ( obtrate) when fired. With lower pressure a softer alloy is needed.

[Rebel Dave]

Use pure Lead. Those guns ran on it, that's what they used back in the day. Use it with black powder also, which is also what was used.

Rebel Dave

[Char-Gar]

The TDs have bore specs all over the map but that didn't seem to matter. The Army used soft lead and black powder and the bullet upset to fill whatever size bore it was fired in. You are on the right track looking for larger and softer bullets.

[Doc Highwall]

I would suggest buying this book.

http://4570products.info/Loading-Cartridges-for-Original-45-70-Springfield-1.htm

[bassin57]

Thank you for the replies...I have just melted wheel weights to ingots. I cast a few cww with the .459 mold and they measure .459. I may powder coat these to add a little diam thickness. The softer stick on wheel weights I am saving to make 20-1 alloy when I have enough alloy to make bullet alloy Larry suggested. I have the Lyman cast 4th edition, but a book more suited for my needs may be needed . Thank you your replies...Bassin57

[MT Chambers]

Slug your bore, use 20-1 or pure lead, and real black powder, in your trapdoor.IMHO

[StrawHat]

20/1 is a bit harder than I like. I am down around 30/1 and sometime 40/1 depending on what the particular rifle likes. I use black powder and an appropriate lube. The lee HB boolit is a good one.

Kevin

[cold1]

I am working on paper patched rounds for mine. I have a reduced load using a Lee 452 RF at 255g paper patched up to .460. It works great. Might even go the PP route for a 400+ grainer this summer.

[aap2]

The Lee hollow base 459-405-HB has worked will in every original trapdoor that I have fired it in using an alloy of 1/20-1/30 tin/lead. You can slug the bore is you want to, but I would pan lube the slugs as cast and load a dummy round and see if it will chamber. If it chambers freely, don't bother with sizing the slug. I think that the late Spence Wolf's book was right about using a HB slug for the light 405gr loads and a properly designed 500gr plain based slug for the heavier loads. Real BP slightly compressed with an enlarged primer flash hole (segregate these cases for BP only) and a firm crimp are accurate and a hoot to shoot; but light smokeless loads (I have used SR4759) also work. IMHO: try loading your Lee 405 hollow-based boolits lubed as cast out of whatever not too hard alloy that you have....The results will probably surprize you.

[44man]

The best boolit we used in a TD was the 500 gr govt boolit from rapine at .461". Cast from 20 to 1 and using 3031. Extremely accurate to 100 yards where we stopped. Fit still works even with softer. The worst was the Lee with the pointy nose, recovered boolits from snow showed off center nose slump with rifling marks on one side of the ogive.
I never got many 405 gr boolits to shoot, most were too small and the sample of Laser Cast were too small.
Even with soft, get boolits to fit what the grooves need.
We proved that with Minie' balls in muskets where a large backstop could not be hit at 50 yards. Lapping the molds for a tight thumb push allowed us to clang steel at 200 meters.
3031 is more accurate and will have less recoil then 4198.

[Doc Highwall]

Mihec just finished a group buy for a hollow base 2 cavity mould for the 45 caliber in .460 and .462 diameter, see if he has any left over.