Trapdoor Springfield problem

[harledavid]

Help! I recently aquired an apparently original model 1873 trapdoor Springfield which was supposed to shoot 45-70. I tried to load some Remington facory loads that were marked safe for all rifles but the breach wouldn't close. I disassembled the cartridge and tried to chamber the casing only after resizing it. No luck; although it fit in the chamber, the breach would not close on it. The rifle has no caliber markings that I can see. Is it possible the caliber has been changed somewhere along the line? The barrel and action all appear to be original. Any suggestions?

[Hawg Haggen]

I wouldn't shoot any smokeless load in a 73. That's just too weak of a receiver.

Do a chamber cast.

[ken22250]

its possible, but doubtful that it is a 50-70, which is a shorter case. check the bore and make sure its a .45 cal. good luck and have fun
ken

[Hawg Haggen]

A chamber cast removes all doubt.

[harledavid]

Thanks for the help. I've never done a chamber cast. Can you give me any guidance?

[the rifleer]

I've never done one, but compare the cast to a round and see in there is any noticeable difference. use a pair of calipers.

[Hawg Haggen]

The best way is to get cerrosafe from Midway or Brownells but crayons will work, they're just more fragile.
Plug the bore about an inch beyond the chamber with a patch. Melt your cerrosafe and fill the chamber and let it cool. Push it out and you have a perfect mold of the chamber including any imperfections. You can measure it and compare it to your loaded rounds. If it doesn't match your loads you can compare measurements for other calibers to find out what you have.
BTW, if you decide to go the cheaper route with crayons, they stink.:D

[harledavid]

Thanks. Before I saw your post, I did a little measuring and got an approximate chamber length of 1.75 inches. I'm pretty sure it's some kind of 45 because a .458 bullet fits the bore and a 45 LC casing chambers fine. Any idea what I have?

[JMtoolman]

I'm fairley sure it is indeed a 45/70. You may have a broken off piece of a case stuck in the front of the chamber. Try a oversize brush on a stout cleaning rod and run it through the barrel and into the action, sometimes it will push a piece of case out with the bore brush. Good luck finding the problem. The toolman.

[Hawg Haggen]

A 45-70 case is 2.035 inches

[whitedemon89]

I use paraffin for chamber casts. Its kind of soft, but it's cheap and easy to find.
Also if there is a broken shell I use a reamer, just a little smaller than the chamber. Drive it in with a mallet and twist slightly as you pull it out.

[harledavid]

Well, I guess if all else fails, take a look. Using a mirror and bore light, it does look like something "brasslike" is down there. I tried the brush thing, even wrapping a couple of patches around it, but no luck. Guess I'll go to a smith and see if he can get it out.

[sundance44s]

You should have to drive a .458 dia bullet into the bore ....if it is an easy fit ..it is a 50 cal .

[harledavid]

Tried it from the muzzle end and stopped at the ogive. I would have had to drive it to get it through and didn't want to get it stuck too with who knows what at the other end. As it turns out, I took it to a smith who confirmed it was a broken case. Also, the firing pin was pretty much frozen, so he's going to check it out thoroughly before I shoot it. Thanks for all the help.