Can anyone suggest Trapdoor loads using a 420 gr lead bullet? Powders I have on hand, in quantity, are Trap 14, Green dot, Unique, 7625, 2400, Surplus 4895, WCC846, WCC844 and Black. Obvioulsly I can load black but I don't care for the clean up, particurarly the brass. I have a feeling the 844 would be good, since it is the closest to 4198, but, I have never seen any loads for it in this application.

Is it one of the old time trapdoor rifles?Or one of the new reproduction rifles?Is it IMR4198 or H4198?

It is an original rifle, I want to be nice to it. I don't have enough IMR 4198 to mess with. I was using that as a comparison to the somewhat simmilar but slower WCC844, a surplus powder, that I use in .223.

With an old girl like you have.I would not go over a 350gr bullet.With IMR4198 keep it low,say 32 to 34 grs of powder.For 1421fps.IMR4227 is a good powder for it also.25.0grs=1271fps,29.0grs=1445fps.

Scott;
I looked in my "Lyman 48th edition" they didn't list any powders you mentioned. I have a cutdown trapdoor, I've had good luck with 23 gr's of Accurate 5744 with a Lyman 457124 bullet.
I also loaded 55gr's of Goex CTG grade black with the same bullet. Cleanup isn't as bad as you would think.

Jim

Why not shoot black powder? It's a blast. Besides, that was what it was designed for and the stuff shoots quite well. Black Powder may even be superior at long range.

I have read that the black powder load is ~10k psi, and original trapdoors chambers fail at ~55kpsi.

Published loads for smokeless powder are ~28 kpsi.



420 gr 28 gr 4895, 10 kpsi, 1124 fps

420 gr 46.4 gr 4895, 28 kpsi, 1727 fps



I have been shooting 30 gr 4895 with 405 gr, and kicks about as much as I can take for target practice. 40 gr kicks me into next week.

I've seen loading manuals with sections for "Trapdoors" or for "All .45-70 Rifles In Good Condition" that seem to limit around 18 Kpsi. The sections for "1886 Winchesters, Modern 1895 Marlins" and such seem to be the ones using the SAAMI limit of 28.5 Kpsi. But I can't imagine that SAAMI would have settled on the pressure limit they did for factory ammo without taking into account the large number of original Springfields out there and assuming that their owners would fire factory ammo.

The 4895 loads look like what I was looking for. I have had good luck with it using pure lead swaged paper patch bullets. I'll give it a try.



My beef with black is the clean up fuss. I don't mind with my hooked breeech muzzle loaders. I have a contraption rigged to my wash sink in the garage. It allows me to flush the bore with hot water. Works great. Even the bore cleaning of a breech loader is no big deal. Especially my rolling blocks. I do have a manual decapper for the brass. It is very fast. I just don't like soaking brass or swabbing it out. My time is at a premium these days. If I get time to shoot I don't want to fuss with a pile of brass after.

Most sources on the max pressure for trapdoors are between 18 and 28 k pis or cup:
http://www.geocities.com/CapitolHill/Lobby/1221/maxpress.htm
http://www.galleryofguns.com/shootingtimes/Articles/DisplayArticles.asp?ID=40
http://www.findarticles.com/cf_dls/m0BQY/9_48/89808647/p1/article.jhtml
http://www.riflemagazine.com/magazine/article.cfm?tocid=637&magid=49
http://www.gmdr.com/lever/4570gtext.htm
http://216.239.57.104/search?q=cache:5DiB9l5GTvYJ:www.speer-bullets.com/pdf/ReloadingSupplementalDATA/4570_300.pdf+maximum+pressure+for+trapdoor&hl=en&start=15&ie=UTF-8
http://www.google.com/url?sa=U&start=8&q=http://www.accuratepowder.com/data/PerCaliber2Guide/Rifle/ObsoleteCartridges/45%252070%2520Trapdoor%2520pages%2520361%2520and%2520362.pdf&e=7764

Try the following link to Accuratearms.com
http://accuratearms.com/loaddata_caliber_rifle_obsolete.htm
XMP5744 is a great powder designed for light loads in larger cases. Click on the 45-70 Trapdoor link.
Works great.