Go Back   CMP Forums > CMP General > Ask Each Other
Register FAQ Members List Calendar Mark Forums Read

Reply
 
Thread Tools Display Modes
  #1  
Old 07-11-2018, 03:59 PM
Nodak71 Nodak71 is offline
 
Join Date: Jan 2014
Location: North Dakota
Posts: 942
Default Shooting a M1873 Trapdoor

This is a question about something I am somewhat ignorant about. I have several of the old trapdoors I have picked up but have never tried to fire any of them. This spring a good friend who I worked with for many years retired and I gave him an extra trapdoor rifle I had as a retirement gift. Today he comes over and wants to shoot this old rifle on my range. I told him I had no gauges for these and thought that the breach block was tight but other than that I was a tad leery of shoothing something that old without having it checked out. He had loaded a few rounds with Pryodex and a 400 grain lead bullet. From what he told me the loading was lighter than the original, something like 50 some grains. The old rifle fired just fine and actually hit the paper but the rounds were actually hitting the paper sideways, keyhole? Was this a function of too weak a load? Just wondering. Thanks
__________________
NRA Life Member
GCA
CMP Customer Since 98

Feedback Thread
http://forums.thecmp.org/showthread.php?t=167261
Reply With Quote
  #2  
Old 07-11-2018, 04:08 PM
Rick B Rick B is offline
 
Join Date: Oct 2009
Location: Hinckley,Ohio
Posts: 1,693
Default

Key holeing is do to a bad barrel or to small of a bullet diameter. The Trapdoors were made to take about 60 Grains of powered. Problem is they need to be cleaned after with Black Powder loads. I have a friend loading modern powder and it is clean burning which makes that not an issue. They are also normally set for 200 yards or more so they shoot high unless you get a higher front site blade. Again Key holeing is a rifle bore or muzzle issue more than a powder issue. Is it a 50/70 and you are shooting 45/70 bullets? Rick B
Reply With Quote
  #3  
Old 07-11-2018, 04:33 PM
Nodak71 Nodak71 is offline
 
Join Date: Jan 2014
Location: North Dakota
Posts: 942
Default

Rick, it is chambered in .45-70, is an 1873 model. Ok the bore could be a problem, it is pitted fairly bad like many. My buddy intends to clean it with hot water/soap when he gets home. This was a rifle I picked up a few years ago from the estate of the old guy who ran Trapdoors Galore out in Vegas. His daughter discounted stuff heavy and sold everything. I have several just to collect but have never tried shooting them. Makes sense about it being a barrel issue. We were sighting low to hit the paper, my range is only about 75 yards so makes sense sights would be off at that distance. Thanks for the info, will pass it on to my friend.
__________________
NRA Life Member
GCA
CMP Customer Since 98

Feedback Thread
http://forums.thecmp.org/showthread.php?t=167261
Reply With Quote
  #4  
Old 07-11-2018, 04:56 PM
bobk bobk is offline
 
Join Date: Mar 2010
Location: SW Texas
Posts: 825
Default

These old trapdoor rifles were notorious for having some variations in bore size. When they were fired with the original ammo, the bullets were soft lead with a hollow base and the full charge of 70 gr. of black powder produced enough pressure to expand the base of the bullet to fill the bore and key holing was not an issue. Most of the lead bullets that are available today are hard lead and flat base so they do not expand. So the key holing can be an issue with many of them. I have one, a very nice almost mint 1884 that keyholes bad, and another one an old grungy 1873 that shoots like a champ, right on with no keyholing. So just shoot them and enjoy and if that keyholing is a problem for you then try another rifle till you find one that doesn't. It's just normal variations in the barrels, nothing you can do about it.
Reply With Quote
  #5  
Old 07-11-2018, 05:11 PM
7,62x51mm 7,62x51mm is offline
 
Join Date: Oct 2009
Location: USA Illinois
Posts: 1,384
Default

Most shooters use .459 or .460 dia lead bullets, you need to slug the bore or else use hollow base bullets.

Years ago I use to drop 5 grs of 4759 in the bottom of the 45-70 case then load the black powder (drop tube is best) bore shoots
clean with the small charge of smokeless..
Reply With Quote
  #6  
Old 07-11-2018, 05:26 PM
Nodak71 Nodak71 is offline
 
Join Date: Jan 2014
Location: North Dakota
Posts: 942
Default

I will ask my friend about the lead bullets he is using, could be too small diameter or too hard lead I guess. Several variables to this problem. I am not sure he is going to try to shoot it again or not. I know there are modern loads at the black powder pressures and other modern loads that are too hot for these old rifles.

I have got some really good information from all of you and I will pass this on. Thanks to all who responded, lot of knowledge on this site.
__________________
NRA Life Member
GCA
CMP Customer Since 98

Feedback Thread
http://forums.thecmp.org/showthread.php?t=167261
Reply With Quote
  #7  
Old 07-11-2018, 05:48 PM
bobk bobk is offline
 
Join Date: Mar 2010
Location: SW Texas
Posts: 825
Default

There is a lot more to shooting these old trapdoor rifles than is readily apparent. The caliber 45/70 is still in use today but mostly for modern rifles like the Marlins and some of the Italian repros. I think it is mostly jacketed bullets and higher pressure smokeless loads which are not suitable at all for the original trapdoor. The original bullets were 405 gr hollow base lead with a ratio of 20:1 lead to tin. The bullet diameter would have to be determined by slugging the barrel and either finding a mold that size or having one custom made. Someone who is going to do a lot of shooting of these would probably go that route, but it can be a little disconcerting to someone who just likes to chamber rounds and shoot away. Kind of reminds me of trucks, someone that is used to driving a new Toyota Tundra or other make and then gets a 1925 Model T truck and thinks he is just going to get in, start it and away we go. No so. There are similarities but also there are a lot of little details that if you are going to get serious about shooting the 1873, you will have to do some research and a bunch of practice to get it right. I have been shooting, building, and restoring these old relics for almost 40 years and I still learn something all the time. I am almost at the point where I am going to cast my own bullets and then try to duplicate the original ammo of the 1880s. It's been a slow process but fun also. I have been using what bullets I have been able to find and they are for the most part hard lead with lube for smokeless powder and these are not the best for black powder loads. But soon I should have all the equipment to make the ammo. I wish you and your friend a lot of luck with these. One alternative if you don't want to get so deep into it is to buy black powder loads from Buffalo Arms. It seems to work quite well but it is quite costly. I don't know of anyone else who is currently selling black powder loads commercially at this time. I used to use the Black Dawg ammo from Goex, but I can't find it anymore so I guess they stopped making it. Well good luck with yours and have a good day.
BobK
Reply With Quote
  #8  
Old 07-11-2018, 09:31 PM
jbrower jbrower is offline
 
Join Date: Oct 2009
Location: SE PA
Posts: 412
Default

A lot of people pick up 405 grain cast bullets that are cast of a hard alloy and try them out in their Trapdoor's with poor results, stuff like keyholing bullets.

The rifling in these rifles is not very deep. Add to that a hard alloy bullet and faster burning powder and it's no wonder that they don't work too well.

These guns were made to be shot with black powder. Also, the Goobermint used a soft alloy bullet, IIRC 20:1 Lead/Tin. Two bullets were used: a 405gn Hollow base bullet (similar to a Minie Ball) and a 500gn solid base bullet.

Upon firing, the 405gn bullet would expand to fill the bore and grip the somewhat shallow rifling. A 500 gn bullet would obturate (expand) and also fill the bore and grip the rifling. Bullets cast with Antimony or too much tin are too hard and won't properly obturate. With smokeless powder it's even worse as the powder burns too fast to give the bullet time to "bump up" and expand into the rifling before it's started its journey down the bore.

I suggest picking up the book "Loading Cartridges for the Original 45-70 Springfield Rifle and Carbine" by J.S. and Pat Wolf. There is lots of good info in there on shooting these old guns.

Last edited by jbrower; 07-11-2018 at 09:33 PM.
Reply With Quote
  #9  
Old 07-12-2018, 09:28 AM
Tam 3 Tam 3 is offline
 
Join Date: Oct 2009
Posts: 46
Default

I have loaded 38 gr. of H4895 behind cast lead from a lyman 457125 mold that that shoots to poa at 200 yds. Remember that the 500 gr. is two tenths of an inch longer than the original 405 gr 1873 load. Measured at 1310 fps across a Chrony. The original bp load I believe was 1315 fps.

Fwiw.

Regards,

Tam 3
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On



All times are GMT -5. The time now is 04:03 AM.